WO2015159434A1

WO2015159434A1 - Steel sheet pile

Info

Publication number: WO2015159434A1
Application number: PCT/JP2014/061085
Authority: WO
Inventors: 鈴木　崇; 裕章中山; 篤史加藤; 典佳原田; 隆太田中; 和秀戸田; 慎也林; 浩山下
Original assignee: 新日鐵住金株式会社
Priority date: 2014-04-18
Filing date: 2014-04-18
Publication date: 2015-10-22
Also published as: JP6108031B2; WO2015159445A1; CN105765130A; JPWO2015159445A1; CN105765130B

Abstract

A steel sheet pile for which a workability evaluation coefficient (C) and an economic evaluation coefficient (E) expressed by formulas (18, 19) below satisfy any of the following conditions (24 - 28) below when the unit weight of the soil of the target foundation (γ) is 1.8×10^-8 kN/mm³, the coefficient of friction (μ) between the soil and the steel sheet pile is tan 15°, the Rankine passive earth pressure coefficient (ν) is tan²(45°+(√15×N+15)/2), the N value is 20, and the installation depth (Z_ν) is 15000 mm. C=F_closure/A (18) E=A₀/Ze (19) 0.12 ≤ C ≤ 0.66 and -0.0225×C+0.066 ≤ E ≤ 0.08 (24) 0.66 <C ≤ 0.85 and -0.0225 × C+0.066 ≤ E ≤ -0.0306×C+0.0997 (25) 0.85 < C ≤ 0.89 and 0.0469 ≤ E ≤ -0.0306×C+0.0997 (26) 0.89 < C ≤ 1.04 and 0.0469 ≤ E ≤ 0.0077×C+0.0793 (27) 1.04 < C ≤ 1.20 and 0.0469 ≤ E ≤ 0.0795 (28)

Description

Steel sheet pile

The present invention relates to a steel sheet pile used as a retaining wall, revetment, etc. in the civil engineering and construction fields.

Conventionally, regarding steel sheet piles, hat-shaped steel sheet piles (for example, see Patent Documents 1 and 2) and Z-shaped steel sheet piles (for example, see Patent Document 3) are generally known.
Patent Document 1 focuses on minimizing the penetration resistance of the hat-shaped steel sheet pile at the time of placing, and shows a hat-shaped steel sheet pile with improved workability. As a workability evaluation technique for the hat-shaped steel sheet pile, a workability index R created based only on the knowledge of a soil tank test of a steel sheet pile scale model is shown. The workability index R is an evaluation formula calculated by the flange width, web angle, and section height of the hat-shaped steel sheet pile, that is, the product of the tangent of the web angle and the ratio (flange width / section height). It is shown that there is a positive correlation between the workability index R and the penetration resistance. Using the workability index R, a hat-shaped steel sheet pile set to a web angle that minimizes penetration resistance with respect to a predetermined second moment of section is characterized.

Patent Document 2 uses the same evaluation formula as the workability index R as a workability evaluation technique for a hat-shaped steel sheet pile, and shows a hat-shaped steel sheet pile with improved economy and workability. Yes.
Patent Document 3 uses an evaluation formula similar to the workability index R as a workability evaluation technique for a Z-shaped steel sheet pile, and shows a Z-shaped steel sheet pile with improved economy and workability. Yes.
Patent Document 4 discloses a method for setting a cross-sectional shape of a Z-shaped steel sheet pile in which economic efficiency and workability are optimized using an evaluation formula similar to the workability index R.
Thus, conventionally, workability is evaluated based on the workability index R as a workability evaluation technique for steel sheet piles.

Japanese Patent No. 3488233 JP 2012-158910 A Japanese Patent No. 4873097 JP 2012-193540 A

However, the workability index R in the conventional hat-shaped steel sheet pile or Z-shaped steel sheet pile has the following problems.
Since the conventional workability index R is created based only on the knowledge of the model test, the applicability to the workability evaluation of a full-scale steel sheet pile has not been verified. Then, the inventor verified the applicability of the workability evaluation to the full-scale steel sheet pile of the conventional workability index R. That is, a full-scale construction test was performed on the full-size steel sheet pile with a placement depth of 13 m, the workability of the full-size steel sheet pile was evaluated based on the workability index R, and compared with the dynamic resistance of each steel sheet pile. Here, the dynamic resistance is a measured value calculated based on the hydraulic pressure value of the construction machine, etc., and the steel sheet pile with a small dynamic resistance has a small hydraulic value necessary for penetration, that is, the placing resistance is suppressed. It is evaluated as a steel sheet pile with excellent workability.

As shown in FIG. 25, when the reference steel sheet pile (steel sheet pile (1)) is set to 1, the relationship between the ratio of the workability index R of each steel sheet pile and the ratio of the dynamic resistance is examined. A correlation of the number 0.401 is obtained. This is contrary to the results obtained in the model tests described in Patent Documents 1 to 3, and the correlation is low.

Next, the limit of the scope of application of the conventional workability index R was investigated in detail. Each steel sheet pile is composed of a first flange and a pair of webs extending from both ends of the first flange, and a pair of second sheets having a joint at the tip extending in parallel with the first flange on the opposite side of the first flange of the web. It is a hat-shaped steel sheet pile made of a flange, and the effective width is 900 mm or less and the effective width is 1270 mm or more when the length between the fitting centers of the pair of joints at the tip of the second flange is the effective width. Steel sheet pile.

When paying attention to the steel sheet pile (4) having an effective width of 900 mm or less, the steel sheet pile (4) has a correlation coefficient between the ratio of the workability index R in FIG. 997, indicating that the correlation is extremely high.
Further, when paying attention to the steel sheet piles (1), (2) and (3) which are steel sheet piles having an effective width of 1270 mm or more, the straight line in which the ratio of the workability index R and the ratio of the dynamic resistance Ru in FIG. The correlation coefficient was 0.349, indicating that the correlation was low.

In other words, the conventional workability index R can be used to evaluate the workability of a full-size steel sheet pile having an effective width of 900 mm or less, and is not applicable to the workability evaluation of a full-size steel sheet pile having an effective width of 1270 mm or more. It was revealed that there is an applicable range related to the effective width for evaluating the workability of large steel sheet piles. That is, it has been clarified that the conventional workability index R has a problem that there is no applicability of workability evaluation of a full-size steel sheet pile with an effective width of 1270 mm or more.
Therefore, there has been a demand for a workability evaluation technique that can reliably apply the workability evaluation of an actual steel sheet pile having an effective width of 1270 mm or more.

Therefore, regardless of the effective width, it is possible to favorably evaluate the workability with respect to the shape of all regions, and in particular, an actual width of 1270 mm or more that is outside the application range of the conventional workability index R. There was room for improvement in terms of workability evaluation technology that enabled evaluation of workability of large steel sheet piles.

The present invention has been made in view of the above-described problems, and creates an obstruction resistance formula indicating occlusion resistance that becomes a dominant resistance when placing a steel sheet pile, and uses this occlusion resistance formula to make existing steel It aims at providing the steel sheet pile of the suitable cross-sectional shape excellent in the performance of at least one among workability and economical efficiency compared with a sheet pile.

In order to achieve the above object, according to the present invention, there is provided a steel sheet pile constituting a wall, which is substantially parallel to the neutral axis of the wall, symmetrically located across the neutral axis and parallel to each other. A steel sheet pile having one flange and a second flange, a web connecting the first flange and the second flange, and having a unit between the midpoints of the adjacent first flanges or the second flanges in the wall body When two flanges provided at both ends of one unit in the steel sheet pile are used as the second flange, a joint for fitting the steel sheet piles is formed at the end of the second flange. and a length of the effective width between the mating centers of the second flange pair of joints formed at the distal end of the effective width is more than 1270 mm, the section modulus Ze is fully the range of 1700 ≦ Ze ≦ 2300cm ³ / m To a steel sheet pile, unit weight γ of 1.8 × ¹⁰ -8 kN / mm ³ of soil subject ground, the friction coefficient μ of tan 15 ° soil and steel sheet pile, the Rankine passive earth pressure coefficient number ν

When the relative density Dr is 80%, the N value is 20, and the placement depth Z _ν is 15000 mm,
A steel sheet pile, wherein the workability evaluation index C and the economic evaluation index E represented by the following formulas (18) and (19) satisfy any of the following formulas (20) to (23): .
C = F _obstruction / A (18)
E = A ₀ / Ze (19)
0.11 ≦ C ≦ 1.00 and −0.0208 × C + 0.0809 ≦ E ≦ 0.0884 (20)
1.00 <C ≦ 1.20 and −0.0208 × C + 0.0809 ≦ E ≦ −0.03 × C + 0.1186 (21)
1.20 <C ≦ 1.40 and 0.0560 ≦ E ≦ −0.03 × C + 0.1186 (22)
1.40 <C ≦ 1.80 and 0.0560 ≦ E ≦ 0.0766 (23)
However, F _occlusion : the following formulas (6), (3) ′, (4), (14), (12), (13), (1) ′ and (2) ′ and (7) or (7) Blocking resistance (kN / sheet) calculated based on ', A: sectional area (cm ² / sheet), A ₀ : sectional area (cm ² / m) per 1 m width in the wall direction at the time of wall formation , Wf: width (mm) of the first flange, H: cross-sectional height (mm) which is a distance between the first flange and the second flange in a direction orthogonal to the neutral axis, θ: the web and the second It is a web angle (°) that is a complementary angle of the angle formed by the flange.

Further, according to the present invention, the steel sheet pile constituting the wall body is substantially parallel to the neutral axis of the wall body, is symmetrically located across the neutral axis, and is parallel to each other. In the steel sheet pile having a flange and a web connecting the first flange and the second flange and having a unit between the midpoints of the adjacent first flanges or the second flanges in the wall body, the steel sheet pile When two flanges provided at both ends of one unit in the above are used as the second flange, a joint for fitting steel sheet piles is formed at the end of the second flange. the length between the mating centers of the pair of joints formed at the tip effective width, the effective width is more than 1270 mm, a steel sheet pile section modulus Ze satisfies the range of 2300 <Ze ≦ 3400cm ³ / m , Unit weight γ of 1.8 × ¹⁰ -8 kN / mm ³ of soil subject ground, the friction coefficient μ of tan 15 ° soil and steel sheet pile, the Rankine passive earth pressure coefficient number ν

When the relative density Dr is 80%, the N value is 20, and the placement depth Z _ν is 15000 mm,
The steel sheet pile, wherein the workability evaluation index C and the economic evaluation index E represented by the following formulas (18) and (19) satisfy any of the following formulas (24) to (28): .
C = F _obstruction / A (18)
E = A ₀ / Ze (19)
0.12 ≦ C ≦ 0.66 and −0.0225 × C + 0.066 ≦ E ≦ 0.08 (24)
0.66 <C ≦ 0.85 and −0.0225 × C + 0.066 ≦ E ≦ −0.0306 × C + 0.0997 (25)
0.85 <C ≦ 0.89 and 0.0469 ≦ E ≦ −0.0306 × C + 0.0997 (26)
0.89 <C ≦ 1.04 and 0.0469 ≦ E ≦ 0.0077 × C + 0.0793 (27)
1.04 <C ≦ 1.20 and 0.0469 ≦ E ≦ 0.0795 (28)
However, F _occlusion : the following formulas (6), (3) ′, (4), (14), (12), (13), (1) ′ and (2) ′ and (7) or (7) Blocking resistance (kN / sheet) calculated based on ', A: sectional area (cm ² / sheet), A ₀ : sectional area (cm ² / m) per 1 m width in the wall direction at the time of wall formation , Wf: width (mm) of the first flange, H: cross-sectional height (mm) which is a distance between the first flange and the second flange in a direction orthogonal to the neutral axis, θ: the web and the second It is a web angle (°) that is a complementary angle of the angle formed by the flange.

Further, according to the present invention, the steel sheet pile constituting the wall body is substantially parallel to the neutral axis of the wall body, is symmetrically located across the neutral axis, and is parallel to each other. In the steel sheet pile having a flange and a web connecting the first flange and the second flange and having a unit between the midpoints of the adjacent first flanges or the second flanges in the wall body, the steel sheet pile When two flanges provided at both ends of one unit in the above are used as the second flange, a joint for fitting steel sheet piles is formed at the end of the second flange. A steel sheet pile satisfying a range between a fitting center of a pair of joints formed at the tips, an effective width, the effective width being 1270 mm or more, and a section modulus Ze of 3400 cm ³ / m <Ze, Earth Unit weight γ of 1.8 × ¹⁰ -8 kN / mm ³ of soil, the friction coefficient μ of tan 15 ° soil and steel sheet pile, the Rankine passive earth pressure coefficient number ν

When the relative density Dr is 80%, the N value is 20, and the placement depth Z _ν is 15000 mm,
The steel sheet pile, wherein the workability evaluation index C and the economic evaluation index E represented by the following formulas (18) and (19) satisfy any of the following formulas (29) to (31): .
C = F _obstruction / A (18)
E = A ₀ / Ze (19)
0.13 ≦ C ≦ 0.36 and −0.0237 × C + 0.0538 ≦ E ≦ 0.0642 (29)
0.36 <C ≦ 0.52 and −0.0237 × C + 0.0538 ≦ E ≦ −0.025 × C + 0.0732 (30)
0.52 <C ≦ 0.75 and −0.0237 × C + 0.0538 ≦ E ≦ 0.0602 (31)
However, F _occlusion : the following formulas (6), (3) ′, (4), (14), (12), (13), (1) ′ and (2) ′ and (7) or (7) Blocking resistance (kN / sheet) calculated based on ', A: sectional area (cm ² / sheet), A ₀ : sectional area (cm ² / m) per 1 m width in the wall direction at the time of wall formation , Wf: width (mm) of the first flange, H: cross-sectional height (mm) which is a distance between the first flange and the second flange in a direction orthogonal to the neutral axis, θ: the web and the second It is a web angle (°) that is a complementary angle of the angle formed by the flange.

In the present invention, a steel sheet pile constituting the wall body, the first flange and the second flange that are substantially parallel to the neutral axis of the wall body, are symmetrically located across the neutral axis, and are parallel to each other, and In the steel sheet pile having a web connecting the first flange and the second flange and having one unit between the midpoints of the adjacent first flanges or the second flanges in the wall body, one unit in the steel sheet pile When the two flanges provided at both ends of the second flange are second flanges, the length between the fitting centers of a pair of joints at the ends of the second flange is the effective width, and the effective sheet width is 1270 mm or more. In the region surrounded by a pair of webs extending from both ends of the first flange and the first flange at the time of placing, frictional resistance generated at the interface between the steel sheet pile surface and the ground overlaps. Therefore, a blockage resistance formula showing the blockage resistance that becomes the dominant resistance when placing steel sheet piles along the blockage region where higher restraint pressure is generated than the surrounding ground is created, and regardless of the effective width based on this blockage resistance formula In addition, it becomes possible to evaluate the blocking resistance with respect to the shapes of all the regions, and it is possible to evaluate the workability suitably.

And the workability evaluation index which shows the ratio with respect to the cross-sectional area of the obstruction | occlusion resistance calculated | required by the said obstruction | occlusion resistance formula per said sheet pile in the existing steel sheet pile, and per 1m of width | variety of the wall direction at the time of wall formation in the existing steel sheet pile According to the graph showing the relationship between the ratio of the cross-sectional area to the section modulus, and the economic evaluation index, the section coefficient Ze discretely classified on the lower limit line of the workability evaluation index and the economic evaluation index Three cross-sectional shape groups are grouped, and the three cross-sectional shape groups formulated as a performance range that defines the upper limit of the steel sheet pile, the lower limit region of the workability evaluation index and the economic evaluation index of the existing steel sheet pile Three formula groups are set, that is, the workability evaluation index and the economic evaluation index of the steel sheet pile to be evaluated are formulated according to the expression group including the section modulus of the steel sheet pile to be evaluated. By comparing with the performance range of the improved workability evaluation index and economic evaluation index, it can be evaluated in comparison with the workability evaluation index and economic evaluation index of the existing steel sheet pile.
The steel sheet pile to be evaluated is an expression group corresponding to the section modulus Ze of the steel sheet pile to be evaluated among the three expression groups, and the workability evaluation index and the economic evaluation index of the steel sheet pile to be evaluated. It can set so that at least one value may become smaller than the value of any existing steel sheet pile.
Therefore, in this invention, compared with the conventional existing steel sheet pile, the cross-sectional steel sheet pile excellent in at least one performance among workability | operativity and economical efficiency can be provided.

Further, in the present invention, a steel sheet pile having a small cross-sectional shape and a large steel sheet pile can be evaluated with a workability evaluation index and an economic evaluation index to determine a suitable cross-sectional shape. For example, the evaluation method of the present invention can be applied even to a steel sheet pile having an effective width of 1270 mm or more for which workability could not be evaluated by the conventional evaluation method.

In the present invention, the length between the fitting centers of the pair of joints at the tip of the second flange is the effective width, and the effective width can be 1270 mm or more.

In the present invention, the cross-sectional height H and the thickness of the first flange excluding the joint, the thickness of the web, or the minimum thickness t which is the minimum thickness among the thicknesses of the second flange, It is preferable that the ratio H / t is set so as to satisfy a range of less than 39.

In the present invention, when the N value of the target ground is less than 35, among the plate height of the first flange, the plate thickness of the web, or the plate thickness of the second flange excluding the joint height H and the joint It is preferable that the ratio H / t to the minimum plate thickness t, which is the minimum plate thickness, is set so as to satisfy the range of less than 45.

Further, in the present invention, the first flange width of the steel sheet pile, the geometric constraint determined by the web angle, and the structural constraint defined by the width-thickness ratio according to the steel material yield strength for buckling prevention are set. Preferably it is.

In this case, the geometric constraints determined by the first flange width and web angle of the steel sheet pile are satisfied. For example, the buckling performance required by the standards is satisfied with the width-thickness ratio constraints set by the EUROCODE class 3 standard as structural constraints. Therefore, it is possible to provide a steel sheet pile that satisfies the geometrical and structural constraints of the steel sheet pile.

In the present invention, the steel sheet pile is preferably manufactured hot. In the manufacture of hot steel sheet piles, it is possible to make a difference in sheet thickness within the cross section of the steel sheet pile, making it possible to increase the thickness of the section where the cross section is easily deformed, and to reduce the cross section deformation at the time of placing. It can suppress more effectively and can suppress an increase in placing resistance.

The steel sheet pile includes a first flange and a pair of webs extending from both ends of the first flange, and a pair of joints having a joint at a tip extending in parallel with the first flange on the opposite side of the web from the first flange. A hat-shaped hat-shaped steel sheet pile having a second flange may be used. The steel sheet pile has a hat shape by fitting a joint into a Z-shaped steel sheet pile comprising a pair of parallel flanges having joints at opposite ends of the web and opposite ends of the web. A pair of Z-shaped steel sheet piles, and in the two-sheet set of Z-shaped steel sheet piles, both flanges on the side where the joint is fitted are the first flanges, and both sides on the side where the joint is not fitted The flange may be the second flange.

According to the steel sheet pile of the present invention, a steel sheet pile having a suitable cross-sectional shape excellent in at least one of workability and economic efficiency compared to any existing steel sheet pile by using an evaluation method in consideration of blocking resistance. Can be provided.
Since it becomes the steel sheet pile in which the obstruction | occlusion resistance which becomes dominant resistance at the time of steel sheet pile driving | running | working was suppressed, a construction load can be reduced and a large construction heavy machine becomes unnecessary and construction cost can be suppressed. In addition, because the ratio of the cross-sectional shape factor (cross-sectional height / minimum sheet thickness), which has a high correlation with the amount of change in the total width that has a large effect on the construction speed, is limited, the total amount of deformation of the steel sheet pile during placement is produced The steel sheet pile with a thin and large cross section with high rigidity is economical because it is possible to perform a good construction equivalent to the driving speed of a steel sheet pile in a healthy state that is suppressed within the tolerance and hardly changes in the entire width. However, it is possible to prevent a decrease in the construction yield.
Furthermore, because it satisfies the structural constraints on buckling prevention specified by the width-to-thickness ratio according to the steel yield strength, it can prevent local deformation at the time of placing while being a thin and economical steel sheet pile. A steel sheet pile can be provided.

It is a figure which shows the structure of the Z-shaped steel sheet pile which makes a hat shape by fitting the hat-shaped steel sheet pile or cross-section with a hat shape, and making it into a hat shape. It is a perspective view which shows the structure of the steel sheet pile for demonstrating the placement resistance evaluation type | formula by embodiment of this invention. It is a figure explaining the obstruction | occlusion area | region of a steel sheet pile. Workability evaluation showing the ratio of blockage resistance and cross-sectional area per pair of Z-shaped steel sheet piles in one pair of hat-shaped steel sheet piles in existing steel sheet piles or by fitting two joints into a hat shape shows an exponential (F _occlusion / a), the relationship between economic evaluation index that indicates the ratio of the cross-sectional area and section modulus per width 1m wall direction during wall formation in existing sheet piles (a 0 _/ Ze) It is. It is a figure which shows the relationship between the coefficient a of the quadratic function of the parabola of the obstruction | occlusion area | region, and the web angle of a steel sheet pile cross section. It is a figure which shows the relationship between the function (Hc) / H which consists of the constant c of the quadratic function of the parabola of the obstruction | occlusion area | region, and the formula comprised from a steel sheet pile cross-section factor. It is a figure which shows the relationship between the function (Uk * L) / A _obstruction | _occlusion regarding an obstruction | occlusion area | region, and the formula comprised from a steel sheet pile cross-section factor. It is a figure which shows the relationship between the placement resistance F by a placement resistance evaluation type | formula, and the placement resistance measured value. It is a figure showing the section modulus of the existing steel sheet pile. It is a figure which shows the flowchart which showed the calculation procedure and calculation conditions of blockage resistance F _obstruction | _occlusion . It is a figure which shows the 1st formula group of FIG. It is a figure which shows the 2nd formula group of FIG. It is a figure which shows the 3rd type | formula group of FIG. It is a figure which shows the relationship between (cross-sectional height / minimum board thickness) ratio and a full width difference of a steel sheet pile. It is a figure which shows the workability | operativity of a steel sheet pile, Comprising: It is a figure which shows the relationship between placement time and placement depth. It is the figure which showed the relationship between the placement resistance F and dynamic resistance by the placement resistance evaluation type | formula by this Embodiment. It is a figure which shows the cross-sectional shape of the steel sheet pile by 1st Example. It is a figure which shows the result of having evaluated the steel sheet pile of FIG. 17 by the 1st formula group. It is a figure which shows the cross-sectional shape of the steel sheet pile by 2nd Example. It is a figure which shows the result of having evaluated the steel sheet pile of FIG. 19 by the 2nd formula group. It is a figure which shows the cross-sectional shape of the steel sheet pile by 3rd Example. It is a figure which shows the result of having evaluated the steel sheet pile of FIG. 21 by the 3rd type | formula group. It is a figure which shows the cross-sectional shape of the steel sheet pile by 4th Example. It is a figure which shows the result of having evaluated the steel sheet pile of FIG. 23 by the 3rd type | formula group. It is a figure which shows the full-scale construction test result which shows the relationship between the workability parameter | index R by a prior art, and dynamic resistance. It is a figure which shows the 1st formula group in case of N value = 1. It is a figure which shows the 2nd formula group in case of N value = 1. It is a figure which shows the 3rd formula group in case of N value = 1. It is a figure which shows the 1st formula group in case of N value = 50. It is a figure which shows the 2nd formula group in case of N value = 50. It is a figure which shows the 3rd formula group in case of N value = 50. It is a graph which shows the ground conditions in the full-scale construction test at the time of setting to the range of (section height H / minimum board thickness t) ratio <= 45. It is a graph which shows the full width difference before and behind casting of the steel sheet pile of (section height H / minimum sheet thickness t) ratio 39. It is a graph which shows the full width difference before and behind casting of the steel sheet pile whose (section height H / minimum sheet thickness t) ratio is 42. It is a graph which shows the full width difference before and behind casting of the steel sheet pile of (section height H / minimum sheet thickness t) ratio 45.

DESCRIPTION OF SYMBOLS 1 Hat-shaped steel sheet pile 2 Z-shaped steel sheet pile 3 Steel sheet pile 11 1st flange 12 Web 13 2nd flange G1 1st type group G2 2nd type group G3 3rd type group

Hereinafter, a steel sheet pile according to an embodiment of the present invention will be described with reference to the drawings.

The steel sheet pile according to the present embodiment is intended for a hat-shaped steel sheet pile 1 having a hat shape or a Z-shaped steel sheet pile 2 having a Z shape. The hat-shaped steel sheet pile 1 and the Z-shaped steel sheet pile 2 are collectively referred to as “steel sheet pile 3”. The steel sheet pile 3 is substantially parallel to the neutral axis of the wall body when the wall body is configured, and is provided with a first flange and a second flange that are positioned symmetrically with respect to the neutral axis and parallel to each other. A web connecting the first flange and the second flange is provided. And it is set as the steel sheet pile which makes between the midpoints of the adjacent 1st flanges or 2nd flanges in a wall a unit. The steel sheet pile as one unit indicates a hat-shaped steel sheet pile 1 or a joint of two (one set) Z-shaped steel sheet piles.

First, the hat-shaped steel sheet pile 1 shown to Fig.1 (a) is demonstrated. The hat-shaped steel sheet pile 1 includes a first flange 11 and a pair of webs 12 extending from both ends of the first flange 11, and extends parallel to the first flange 11 on the opposite side of the web 12 from the first flange 11. It is a hat-shaped steel sheet pile having a pair of second flanges 13 having a joint at the tip.
The Z-shaped steel sheet pile 2 is a Z-shaped steel sheet pile comprising a web 12 and a pair of

parallel flanges

11 and 13 having joints at opposite ends of the web 12 extending in opposite directions. In the case where a pair is formed by fitting a joint into a hat-shaped steel sheet pile, the first flange 11 composed of both flanges on the side where the joint is fitted and the second side on the side where the joint is not fitted And a flange 13.

In the steel sheet pile 3 of the present embodiment, as shown in FIGS. 2 and 3, in a region surrounded by the first flange 11 and a pair of webs 12 extending from both ends of the first flange 11 at the time of placing. Since the frictional resistance generated at the interface between the steel sheet pile surface and the ground overlaps, a closed region in which a higher restraint pressure than the surrounding ground is generated is formed. As shown in FIG. 2, a blocking resistance that becomes a dominant resistance when a steel sheet pile is placed is generated in the blocking region. An obstruction resistance type F _occlusion that indicates the occlusion resistance is newly created and acts on the outer peripheral surface excluding the _{tip of} the tip resistance F acting on the cross-section of the sheet pile _tip and the peripheral surface facing the obstruction area, for which the evaluation method is already known. A placement resistance evaluation formula for determining the placement resistance F, which is the sum of the placement resistance F and the _outer circumference resistance F to be performed, is created. The placement resistance evaluation formula is based on the actual construction test results described later. It has been verified that it is possible to evaluate the workability in the region of the effective width that was outside the application range of the conventional workability index R. In other words, the validity of the workability evaluation of the newly created blockage resistance formula has been confirmed. In order to devise a cross-sectional shape of a hat-shaped steel sheet pile or Z-shaped steel sheet pile that has better workability than existing steel sheet piles, we focus on the blocking resistance, which is the dominant resistance of placing resistance, and block more than existing steel sheet piles. As a workability evaluation index for finding the cross-sectional shape in which the resistance is suppressed, the blocking resistance per one hat-shaped steel sheet pile or the set of two Z-shaped steel sheet piles determined by the blocking resistance formula ( In order to devise a hat-shaped steel sheet pile or a Z-shaped steel sheet pile that is set with a workability evaluation index (F _closed / A) indicating the ratio of the F _closed ) to the cross-sectional area (A), and further excellent in economy. The economic evaluation index (A ₀ / Ze) indicating the ratio of the cross-sectional area A ₀ per 1 m width in the wall direction at the time of wall formation and the section modulus Ze is set, and the workability evaluation index and the economic evaluation index are Graphs expressed as horizontal and vertical axes, respectively There will be created.

FIG. 4 shows the ratio of the cross-sectional area of the occlusion resistance per one set of Z-shaped steel sheet piles per pair of the hat-shaped steel sheet piles in the existing steel sheet piles or in a hat shape by fitting a joint. The relationship between the workability evaluation index shown and the economic evaluation index (A ₀ / Ze) showing the ratio of the cross-sectional area A ₀ and the section modulus Ze per 1 m width in the wall direction at the time of wall formation in the existing steel sheet pile The graph is shown. Furthermore, three cross-sectional shape groups according to the section modulus Ze discretely classified in the lower limit line of the workability evaluation index and the economic evaluation index are grouped, and the workability evaluation index and the economic evaluation index of the existing steel sheet piles Three formula groups (first formula group G1, second formula group G2, and third formula group G3 described later) corresponding to the three cross-sectional shape groups formulated as performance ranges that define the lower limit region as the upper limit of the steel sheet pile 3. ) Is set, and in the formula group corresponding to the section modulus Ze of the steel sheet pile 3 to be evaluated, the workability evaluation index (F _occlusion / A) and the economic evaluation index (A) of the steel sheet pile 3 to be evaluated ₀ / Ze), at least one value is set to be smaller than any existing steel sheet pile value.

The above-mentioned blocking resistance type will be described more specifically.
As shown in FIGS. 2 and 3 (a), when the steel sheet pile 3 is placed, in the region surrounded by the first flange 11 and the pair of webs 12 extending from both ends of the first flange 11 at the time of placing, There is a blockage region (blocking area A _blockage ) where a high parabolic ground stress is generated along the first flange 11 side and convex toward the first flange 11 side in a top view. F _blockage occurs.

This is because the inventor conducted a soil tank test of 1/5, 1 / 7.5, and 1/10 scale steel sheet pile models with different similar laws to the actual steel sheet pile, and the steel after the test. It is based on the result of observing the crushed soil particles adhering to the sheet pile and the surrounding ground. The fact that the soil particles are crushed indicates that high stress was generated at that location. As will be described in detail below, as shown in FIG. 3A, the shattered and finely ground soil particles are surrounded by a first flange 11 and a pair of webs 12 extending from both ends of the first flange 11. In the region, it was confirmed that the region was along the first flange 11 side and adhered in a parabolic shape convex to the first flange 11 side in a top view to form a closed region (see FIG. 3B). Moreover, it became clear that the formation situation of the adhesion soil of a steel sheet pile, ie, the shape of the parabola B of the obstruction | occlusion area | region, changes with the cross-sectional shape of a steel sheet pile.

Further, when the relationship between the coefficient a of the quadratic function of the parabola in the closed region and the distance c from the flange surface to the parabola apex and the cross-sectional shape is investigated, the steel sheet pile model with a scale of 1/5 is shown in FIG. as shown in 7, coefficient a quadratic function of the parabola B occlusion region, function consisting distance c from the origin O to the parabola vertex in FIG 3 (a) (H-c ) / H and occlusion area a _closure, It consists of a function of the peripheral length U of the steel sheet pile 3 facing the closed region, the peripheral length L of the parabola B in the closed region, and the ratio k of the friction force between the steel sheet pile and the ground and the ground-ground friction force (U− k × L) / A _obstruction , cross-sectional web angle θ, and (first flange width Wf / cross-section height H) ratio have a relationship shown in expressions (1) to (4). It became clear.

Further investigation of the closed region confirmed that the shape of the closed region of the steel sheet pile models having a plurality of different scale ratios in which the cross-sectional shape of the steel sheet pile model is similar has a substantially similar relationship. That is, when the scale ratio as a representative value is set to 1/5, for example, the shape of the closed region in the steel sheet pile model with a scale of 1/5 is related to the cross-sectional shape factor by the formulas (1) to (4). The circumferential length U of the steel sheet pile 3 facing the closing region and (U−k × L) necessary for calculating the closing resistance described later using these equations (1) to (4) / A _blockage can be calculated. And in the case where the cross-sectional shape of the steel sheet pile model is similar, the shape of the closed region is also substantially similar, so the circumferential length U of the steel sheet pile 3 facing the closed region for the full-scale steel sheet pile, (U -k × L) / a 5-fold of the _closure respectively model, evaluates to 1/5-fold is calculated clogging resistance Jitsudai sheet piles. For this reason, in the calculation of a full-scale steel sheet pile, when the equations (1) to (3) are transformed by multiplying by a coefficient of 5, the equations (1) ′ to (3) ′ are obtained. About the validity of the evaluation method of the obstruction resistance of the full-scale steel sheet pile calculated in this way, it is confirmed by the full-scale steel sheet pile construction test result mentioned later.

Moreover, the friction coefficient of soil and a steel sheet pile model test body is set, the occlusion resistance evaluated by the occlusion resistance formula which will be described later based on the relational expression of equations (1) to (4) from the cross-sectional shape, and the separately evaluated tip end of the sheet pile acting sectional tip resistance F _tip and the outer peripheral resistance F _periphery acting on the outer peripheral surface excluding the peripheral surface facing the closed area, the sum of the pouring resistance evaluation formula and pouring resistance F scale 1/5 of The measured values of the steel sheet pile model were compared. As a result, as shown in FIG. 8, the value of the casting resistance F according to the casting resistance evaluation formula at each depth shows a good agreement with the measured casting resistance value. The validity of modeling can be confirmed.

The placement resistance evaluation formula shown in Formula (5) is composed of a pair of webs extending from both ends of the first flange and the first flange, and the tip of the web extends in parallel with the first flange on the opposite side of the first flange. In a hat-shaped steel sheet pile made up of a pair of second flanges having joints on the web, and a Z-shaped steel sheet pile made up of a pair of parallel flanges having joints at the ends extending in opposite directions to both ends of the web and web, In a Z-shaped steel sheet pile that is a set of two hat-shaped steel sheet piles or joints fitted into a hat shape, the effective width of the hat-shaped or the set of two Z-shaped steel sheet piles is 1270 mm or more In this case, in the set of two Z-shaped steel sheet piles, when both flanges on the side where the joint is fitted are used as the first flange and both flanges on the side where the joint is not fitted are used as the second flange, Setting In the region surrounded by the first flange and a pair of webs extending from both ends of the first flange, the frictional resistance generated at the interface between the steel sheet pile surface and the ground overlaps to generate a higher restraining pressure than the surrounding ground. Blocking resistance F _blockage, which is a dominant resistance when placing steel sheet piles along the blocking region, tip of resistance _tip F (pure cross-section tip resistance force) acting on the tip section (cross-sectional area A) of steel sheet pile 3, the steel sheet pile It is represented by the sum of the _outer periphery resistance F acting on the outer peripheral surface excluding the peripheral surface facing the closed region.

As shown in FIG. 1, the blocking resistance F _blockage of the above formula (5) is the first flange width Wf of the cross-sectional shape of the steel sheet pile 3, and the web angle which is a complementary angle of the angle formed by the web 12 and the second flange 13. It is calculated based on θ and the section height H. That is, the blockage resistance F _blockage is expressed by Equation (6). A _blockage area is A, U is the circumference of the steel sheet pile 3 facing the blockage region, L is the circumference of the parabola B in the blockage region, and (U−k × L) / A _blockage is as shown in FIG. The web angle θ of the cross-sectional shape, the cross-sectional height H, and the first flange width Wf are calculated by Equation (3). Note that σ _v is the vertical stress in the closed region, and is calculated by Equation (7). In the formula (7), γ is a unit volume weight of the soil (for example, 1.8 × 10 ⁻⁸ kN / mm ³ ). Here, σ _v in equation (7) is equal to or less than the product of the passive earth pressure coefficient and the effective earth cover pressure determined by the N value and relative density of the target ground.

In Expression (7), μ is a friction coefficient between the soil and the steel sheet pile 3 expressed as μ = tan δ. For example, δ = 15 ° is generally used. Z _v are striking設深degree, [nu is a Rankin Passive earth pressure coefficient ^{(ν = tan 2 (45 °} + φ ° / 2), internal friction angle phi is calculated from the value of N for example, the target ground.

Tip resistance F _tip becomes Equation (8). Here, α is a bearing force coefficient, A is a cross-sectional area (mm ² ), and N is a tip N value of the target ground. The bearing capacity coefficient α is set to α = 200 in the road earthwork temporary structure guideline (Japan Road Association, March 1999, pages 68 to 70).

The outer periphery resistance F _{outer periphery} becomes Formula (9). Here, K ₀ is a YAKEY's static earth pressure coefficient (K ₀ = 1−sin φ), and the internal friction angle φ is calculated from the N value of the target ground, for example.

The _{outer periphery} of the U is the peripheral length of the outer peripheral surface excluding the peripheral surface facing the closed region of the steel sheet pile, that is, the outer peripheral length of the closed region, and the intersection coordinates (X ₀ , Y) of the closed area A and the steel sheet pile 3 shown in FIG. ₀ ) is calculated by the simultaneous equations of the parabola B and the straight line T, the equations (10) and (11). Then, the intersection coordinates _(X 0, _{Y 0)} is the official solution, equation (12), can be represented by as a, c of the formula (13), the circumferential length of the steel sheet pile 3 facing the closed area U that is can be calculated by the equation (14). Here, X ₀ is a value greater than zero. And the U _outer periphery which is the obstruction | occlusion area | region outer periphery length becomes the length which deducted U which is the perimeter of the steel sheet pile 3 which faces a obstruction | occlusion area | region from the periphery length of the steel sheet pile 3. FIG.

Note that when the parabola B does not have a solution, such as when the web angle θ, which is a complementary angle of the angle formed by the web 12 and the second flange 13, becomes extremely loose, it means that the closed region does not occur. In that case, what is necessary is just to evaluate that it becomes more than the performance of the existing cross section only about economy. That is, when the inventor evaluated the workability of the existing cross section, the existing cross section has a closed region and a blocking resistance is generated. Since it is clear that it is excellent, it is sufficient to evaluate that only the economic efficiency is equal to or better than the performance of the existing cross section.

Next, the workability evaluation index and the economic evaluation index of the present embodiment will be specifically described. FIG. 4 shows the blockage resistance F _occlusion and cross-sectional area per Z-shaped steel sheet pile per pair of hat-shaped steel sheet piles in existing steel sheet piles or in a hat shape by fitting a joint. a workability evaluation index indicating a ratio of a (F _occlusion / a), economy shows a cross-sectional area a ₀ and the ratio of the section modulus Ze per 1m wide wall direction during wall formation in existing sheet piles evaluation index ( A ₀ / Ze) is a graph showing the relationship. The unit of F _occlusion / A is (kN / sheet) / (cm ² / sheet), and the unit of A ₀ / Ze is (cm ² / m) / (cm ³ / m).

In the graph of FIG. 4, the horizontal axis is the workability evaluation index (F _occlusion / A), and the smaller this value, the harder it is to occlude and it can be evaluated that the cross section is excellent in workability. The vertical axis is the economic evaluation index (A ₀ / Ze). The smaller this value, the cross-sectional area per 1 m in the wall direction when forming the wall, and the lighter the steel weight, the better the economic efficiency. It can be evaluated that there is. In addition, calculation of blockage resistance F _blockage per set of Z-shaped steel sheet piles per pair of hat-shaped steel sheet piles in existing steel sheet piles or by fitting two joints into a hat shape. A flow chart showing the procedure and calculation conditions is shown in FIG. 10, and the blocking resistance F _blocking is the web angle θ of the cross-sectional shape, the section height H, the first flange width Wf, and the calculation conditions μ = 0.27, ν. = 3.3, γ = 1.8 × 10 ⁻⁸ kN / mm ³ , Z _v = 15000 mm, N value of 20, and relative density Dr = 80%.

Here, in the calculation conditions, for example in N value 20 of the target ground to the relative density Dr (%) 80% of ground, are calculated under the conditions Da設the steel sheet pile 3 with striking設深of _{Z v} of 15000mm However, it is not limited to such ground conditions and placement depth. In particular, the N value of the target ground as the ground condition is an example of a calculation condition, and the value is not limited to 20. For example, the N value is defined within a range of 0 to 50, The blockage resistance F _blockage is calculated based on the calculation conditions associated therewith. Here, sigma _v of formula (7) is hit設深degree Z _v has been expressed as an exponential function of, not capable of increased indefinitely in response to striking設深degree Z _v, the upper limit defined by ground Have That is, when σ _v increases according to the placement depth Z _v and rises to a stress level at which the ground at the steel sheet pile tip is in a passive fracture state, the ground at the steel sheet pile tip is in a broken state. _v never increases. Therefore, σ _v in equation (7) is the product (v × σ) of the passive earth pressure coefficient (ν), the effective soil cover pressure (σ _v0 ) determined by the N value (N) of the target ground, and the relative density (Dr). _v0 ) or less. For the evaluation method of effective soil cover pressure (σ _v0 ) of the target ground, see, for example, the technical standards and explanations of port facilities (Japan Port Association, July 2007, Vol. 320-321) As shown, Dr (%) = 21 × [100 × N / (σ _v0 +70)] When the relational expression of ^0.5 is applied, σ _{v in the} equation (7) is {ν × (441 × N ) / Dr ² −0.7} × 10 ⁻⁴ kN / mm ² or less.
That is, σ _v is

If
sigma _v is calculated by the lower of the formula (7) and (7) '.

In the graph of FIG. 4, the workability evaluation index of the existing steel sheet pile is grouped into three cross-sectional shape groups according to the section modulus Ze discretely classified by the lower limit line of the workability evaluation index and the economic evaluation index. And three formula groups (first formula group G1, second formula group G2, second formula group corresponding to the three cross-sectional shape groups formulated as performance ranges defining the lower limit region of the economic evaluation index as the upper limit of the steel sheet pile 3. A group of three formulas G3) is set. The reason why three formula groups corresponding to the section modulus Ze are set is that the existing steel sheet pile having a section coefficient of 1700 cm ³ / m or more has a section modulus of 1700 ≦ Ze ≦ 2300 cm ³ / This is because it is divided into three groups of m, 2300 <Ze ≦ 3400 cm ³ / m and 3400 cm ³ / m <Ze. In addition, one reason why the section modulus of existing steel sheet piles is roughly divided into three groups is that the group of cross-sectional shapes of existing steel sheet piles, which have different cross-sectional sizes and required rolling capacities during manufacturing, are related to manufacturing efficiency. Further, it can be mentioned that the cross-sectional shape and the required shape-reducing ability at the time of manufacturing are gathered and manufactured in a cross-sectional shape group of three cross-section coefficient classes.
Specifically, the formula group includes a first formula group G1 corresponding to the range of the formula (15), a second formula group G2 corresponding to the range of the formula (16), and a third formula corresponding to the range of the formula (17). It is divided into the formula group G3.

In addition, since the existing steel sheet pile with the largest section modulus Ze is less than about 5500 cm < ³ > / m, the limit line of the 3rd formula group G3 mentioned later is the range of the section modulus of the existing steel sheet pile 3400 <Ze <= 5500 cm < ³ >. It is set under the condition of / m. In addition, when producing the steel sheet pile 3 in which the section modulus Ze exceeds 5500 cm < ³ > / m, the economical performance and the performance of workability should just be compared with the performance range shown by 3rd type | formula group G3. That is, the group of equations corresponding to the steel sheet pile 3 having a section modulus Ze exceeding 3400 cm ³ / m is the third equation group G3.

Each formula group G1, G2, G3 is composed of formulas showing a plurality of limit lines as shown in FIG. 11 to FIG. 13, respectively. These limit lines correspond to the formula groups G1 to G3 in FIG. It is a line which envelops the lower limit of each of many plots. However, these lines do not include the plot.
Of the limit lines of these formula groups G1, G2, and G3, the lower limit line holds a steel sheet pile having a hat-shaped cross section or a Z-shaped steel sheet pile that is made into a hat shape by fitting two joints into a hat shape. The geometrical constraints determined from the first flange width Wf and the web angle θ of the steel sheet pile 3 and the structural constraints defined by the width-thickness ratio according to the steel yield strength for preventing buckling are set. Yes.
As geometric constraints, the first flange width is Wf> 0 and the web angle is 0 ° <θ <90 °.
The structure as a constraint, for example, the width-thickness ratio of class3 shown in Eurocode (Reference :( first flange width Wf / flange thickness tf) / ε <66, wherein the yield strength 240 N / ^m when the ² epsilon = 0. 99) is a limitation.

The limit lines (formulas) constituting each formula group described above will be described more specifically.
As shown in FIG. 11, the first expression group G1 includes seven limit lines G1a, G1b, G1c, G1d, G1e, G1f, and G1g.
The first limit line G1a is represented by A ₀ /Ze=0.0766 when 1.40 ≦ (F _occlusion / A) ≦ 1.80, and becomes the upper limit line of the economic evaluation index of the first formula group G1. .
The second limit line G1b is expressed by A ₀ /Ze=−0.03×(F _occlusion / A) +0.1186 when 1.00 ≦ (F _occlusion / A) ≦ 1.40, and the first expression group It corresponds to the upper limit line of the economic evaluation index and workability evaluation index of G1.
The third limit line G1c is represented by A ₀ /Ze=0.0884 when 0.11 ≦ (F _occlusion / A) ≦ 1.00, and corresponds to the upper limit line of the economic evaluation index of the first formula group G1 To do. The fourth limit line G1d is expressed by F _occlusion / A ₌ 0.11 in 0.0785 ≦ (A ₀ /Ze)≦0.0884, and is set in the first expression group G1 set from geometric constraints or structural constraints. The lower limit line is shown.
The fifth limit line G1e is represented by A ₀ /Ze=−0.0208×(F _occlusion / A) +0.0809 when 0.11 ≦ (F _occlusion / A) ≦ 1.20, and is set from the structural constraints. The lower limit line of the first expression group G1 is shown.
The sixth limit line G1f is represented by A ₀ /Ze=0.0560 when 1.20 ≦ (F _occlusion / A) ≦ 1.80, and represents the lower limit line of the first expression group G1 set from the structural constraints. Show.
The seventh limit line G1g is represented by F _occlusion / A ₌ 1.8 in 0.0560 ≦ (A ₀ /Ze)≦0.0766, and corresponds to the upper limit line of the workability evaluation index of the first formula group G1 To do.

As shown in FIG. 12, the second expression group G2 is composed of eight limit lines G2a, G2b, G2c, G2d, G2e, G2f, G2g, and G2h.
The first limit line G2a is represented by A ₀ /Ze=0.0713 when 1.04 ≦ (F _occlusion / A) ≦ 1.20, and corresponds to the upper limit line of the economic evaluation index of the second formula group G2. To do.
The second limit line G2b is expressed as A ₀ /Ze=−0.0077×F _occlusion / A ₊ 0.0793 when 0.89 ≦ (F _occlusion / A) ≦ 1.04, and the economy of the second equation group G2 It corresponds to the upper limit line of the workability evaluation index and the workability evaluation index.
The third limit line G2c is represented by A ₀ /Ze=−0.0306×F _occlusion / A ₊ 0.0997 when 0.66 ≦ (F _occlusion / A) ≦ 0.89, and the economy of the second equation group G2 It corresponds to the upper limit line of the workability evaluation index and the workability evaluation index.
The fourth limit line G2d is represented by A ₀ /Ze=0.0795 when 0.12 ≦ (F _occlusion / A) ≦ 0.66, and corresponds to the upper limit line of the economic evaluation index of the second formula group G2. To do.
The fifth limit line G2e is represented by F _occlusion / A ₌ 0.12 in 0.0633 ≦ (A ₀ /Ze)≦0.0795, and is the second expression group G2 set from geometric constraints or structural constraints. The lower limit line is shown.
The sixth limit line G2f is represented by A ₀ /Ze=−0.0225×F _occlusion / A ₊ 0.066 when 0.12 ≦ (F _occlusion / A) ≦ 0.85, and is set from the structural constraints. The lower limit line of group 2 group G2 is shown.
The seventh limit line G2g is represented by A ₀ /Ze=0.0469 when 0.85 ≦ (F _occlusion / A) ≦ 1.20, and represents the lower limit line of the second expression group G2 set from the structural constraints. Show.
The eighth limit line G2h is represented by F _blockage / A ₌ 1.2 in 0.0469 ≦ (A ₀ /Ze)≦0.0713, and corresponds to the upper limit line of the workability evaluation index of the second formula group G2. To do.

As shown in FIG. 13, the third expression group G3 is composed of six limit lines G3a, G3b, G3c, G3d, G3e, and G3f.
The first limit line G3a is represented by A ₀ /Ze=0.0602 when 0.52 ≦ (F _occlusion / A) ≦ 0.75, and corresponds to the upper limit line of the economic evaluation index of the third formula group G3 To do.
The second limit line G3b is expressed by A ₀ /Ze=−0.025×F _occlusion / A ₊ 0.0732 when 0.36 ≦ (F _occlusion / A) ≦ 0.52, and the economy of the third equation group G3 It corresponds to the upper limit line of the workability evaluation index and the workability evaluation index.
The third limit line G3c is represented by A ₀ /Ze=0.0642 when 0.13 ≦ (F _occlusion / A) ≦ 0.36, and corresponds to the upper limit line of the economic evaluation index of the third formula group G3 To do.
The fourth limit line G3d is expressed by F _occlusion / A = 0.13 when 0.0506 ≦ (A ₀ /Ze)≦0.0642, and is set in the third expression group G3 set from geometric constraints or structural constraints. The lower limit line is shown.
The fifth limit line G3e is represented by A ₀ /Ze=−0.0237×F _occlusion / A ₊ 0.0538 when 0.13 ≦ (F _occlusion / A) ≦ 0.75, and is set from the structural constraints. The lower limit line of group 3 group G3 is shown.
The sixth limit line G3f is represented by F _occlusion / A = 0.75 when 0.0360 ≦ (A ₀ /Ze)≦0.0602, and corresponds to the upper limit line of the workability evaluation index of the third formula group G3 To do.

Further, FIG. 14 shows a ratio (H / t) of (section height H / minimum sheet thickness t) which is a section shape factor having a high correlation with the section deformation at the time of construction, and was obtained in an actual construction test. It is data. Since a full-scale steel sheet pile may be constructed by holding the first flange at the site, an eccentric external force may act on the steel sheet pile, and the steel sheet pile cross section may be deformed. When the steel sheet pile cross-section is deformed, the placement resistance may increase according to the change in the cross-sectional shape. Then, when the relationship between cross-sectional deformation and various shape factors was investigated based on the actual construction test results of a plurality of steel sheet piles, when H / t exceeded 39, there was a relationship that a cross-sectional deformation exceeding 10 mm was caused in the total width difference. It became clear that there was. That is, it has been clarified that when the JIS production tolerance is 10 mm in total width and H / t exceeds 39, a large cross-sectional deformation exceeding the JIS production tolerance occurs. From this knowledge, if the ratio of the cross-sectional height H to the minimum flange thickness t of the first flange plate thickness, web plate thickness or second flange plate thickness exceeds 39, a large deformation exceeding 10 mm of the JIS production tolerance occurs. It is desirable that the constraint value of the ratio between the cross-sectional height H and the minimum plate thickness t is less than 39.
Note that the data shown in FIG. 14 and the value of the constraint value 39 of H / t are for a standard ground on which a steel sheet pile having an N value of less than 50 on the target ground can be placed without an auxiliary method such as a water jet. Therefore, although the constraint value varies depending on the type and strength of the ground, using this index with the N value 50 of the target ground as the upper limit can cover normal steel sheet pile driving.

FIG. 15 compares the construction time of the steel sheet pile (5) with H / t <39 shown in FIG. 14 and the steel sheet pile (6) with H / t = 39. As a result, the steel sheet pile (6) has a longer placement time than the steel sheet pile (5) as the placement depth becomes 7 m or less, and is about twice as long as the steel sheet pile (5) by the 15 m placement. It can be confirmed that the workability is significantly reduced. Therefore, good workability can be secured by setting H / t to less than 39.

Next, it is verified that the placement resistance F by the placement resistance evaluation formula created in the present embodiment can be quantitatively evaluated from the viewpoint of workability of a full-size steel sheet pile as shown in FIG. ing.
FIG. 16 shows the ratio of the placing resistance F and the ratio of the dynamic resistance Ru according to the placing resistance evaluation formula according to the present embodiment of each steel sheet pile when the steel sheet pile (steel sheet pile (1)) as the reference is 1. FIG. Each steel sheet pile in FIG. 16 includes a steel sheet pile having an effective width of 900 mm or less and an effective width of 1270 mm or more. In this case, the correlation coefficient between the ratio of the placement resistance F and the ratio of the dynamic resistance Ru according to the placement resistance evaluation formula is 0.912, and the placement resistance evaluation formula is the shape of all regions regardless of the effective width. On the other hand, it is possible to suitably evaluate the workability, that is, it is possible to evaluate the workability of a full-scale steel sheet pile having an effective width of 1270 mm or more that is outside the scope of application of the conventional workability index R. I can confirm.

Next, the effect | action of the steel sheet pile mentioned above is demonstrated in detail based on drawing. As shown in FIGS. 2 and 3, in the present embodiment, in the steel sheet pile having a hat shape or a Z shape, both ends of the first flange 11 and the first flange 11 at the time of placing shown in the above formula (6). In a region surrounded by a pair of webs 12 extending from the steel sheet pile, the friction resistance generated at the interface between the steel sheet pile surface and the ground overlaps, so that the steel sheet pile is driven along the closed region where a higher restraint pressure is generated than the surrounding ground. The blockage resistance formula that uses the blockage resistance F _blockage, which is a typical resistance, as a calculation item is created, and the blockage resistance F _blockage is evaluated based on this blockage resistance equation. It is possible to suitably evaluate the workability with respect to the shape of, and in particular, the length between the fitting centers of a pair of joints at the tip of the second flange that is outside the scope of application of the conventional workability index R Is the effective width The effective width is possible workability Evaluation of Full Scale sheet piles over 1270 mm.

Then, using the closing resistor F _closed, a closing resistor F _occlusion of Z-shaped steel sheet pile per set comprising a set of two you hat shape by the hat-shaped steel sheet pile fitted with one or per joint together a workability evaluation index that indicates the ratio of the cross-sectional area a, graph the relationship between the economic evaluation index indicating the cross-sectional area a ₀ and the ratio of the section modulus Ze per 1m wide wall direction during wall formation in existing sheet piles By grouping the cross-sectional shape groups according to the section modulus Ze, the first expression group G1 to the third expression group G3 sorted according to the section modulus Ze described above are provided, and this is the performance range of the steel sheet pile 3 It can be.

Therefore, it becomes possible to set the limit area | region of a workability evaluation index and an economical evaluation index by these formula groups G1, G2, and G3. That is, the workability evaluation index and the economic evaluation index of the steel sheet pile 3 to be evaluated are the workability evaluation index and economic evaluation formulated by the formula group G including the section modulus Ze of the steel sheet pile 3 to be evaluated. In the limit region of the index, it can be evaluated in comparison with the workability evaluation index and the economic evaluation index of the existing steel sheet pile. The steel sheet pile to be evaluated can be set so that at least one of the workability evaluation index and the economic evaluation index is smaller than the value of any existing steel sheet pile.
Therefore, compared with the conventional existing steel sheet pile, the steel sheet pile of the cross-sectional shape excellent in at least one performance among workability and economical efficiency can be provided.

Further, in the present embodiment, in a steel sheet pile having a hat shape or a Z shape, a steel sheet pile having a suitable cross-sectional shape is evaluated with a workability evaluation index and an economic evaluation index for a steel sheet pile having a small cross-sectional shape. Can be determined. For example, when the effective width is the length between the fitting centers of a pair of joints at the tip of the second flange, which is outside the scope of the conventional workability index R, the effective width is 1270 mm or more. Even if it is a large steel sheet pile, this evaluation method can be applied.

Further, in the present embodiment, the (section height / minimum thickness) ratio, which is a sectional shape factor having a high correlation with the section deformation at the time of construction, is provided as a constraint value of the formula group, and (section height / minimum thickness) By setting it as the steel sheet pile which becomes the range of ratio <39, the construction which suppressed the deformation amount of the full width of the steel sheet pile within the JIS production tolerance can be performed.

Moreover, in this Embodiment, as shown to said Formula (6), it applies to a full-scale steel sheet pile from the 1st flange width Wf, web angle (theta), and cross-section height H of the cross-sectional shape of the steel sheet pile of evaluation object. A series of possible formulas: Formula (3) ′, Formula (4), Formula (14), Formula (12), Formula (13), Formula (1) ′ and Formula (2) ′ and Formula (7) Or there exists an advantage which can calculate the _{obstruction |} occlusion resistance F _{obstruction | occlusion} easily using Formula (7) '.

Furthermore, in the present embodiment, for example, a hat-shaped steel in which the width-thickness ratio constraint set in the EUROCODE class 3 standard is a structural constraint, and the cross-sectional shape determined from the first flange width and web angle of the steel sheet pile is a hat shape. A set of formulas that satisfy the geometric constraints for holding a pair of Z-shaped steel sheet piles in a hat shape by fitting a sheet pile or a joint can be set, and the performance required by the standard is satisfied A steel sheet pile having a cross-sectional shape can be provided.

In the steel sheet pile according to the present embodiment described above, a steel sheet pile having a suitable cross-sectional shape excellent in at least one of workability and economic efficiency as compared with existing steel sheet piles by using an evaluation method in consideration of blocking resistance. Can be provided.

Next, examples for supporting the effects of the steel sheet pile according to the above-described embodiment will be described below.

(First embodiment)
In the first embodiment, the steel sheet pile shown in FIG. 17 has a section modulus Ze of 1700 ≦ Ze ≦ 2300 cm ³ / m (formula (15)) in the first formula group G1 (see FIG. 18). It is an example. In this 1st Example, it is a Z-shaped steel sheet pile which makes a pair by fitting two joints and each dimension is shown in FIG. In addition, as shown in FIG. 18, the lower limit of the workability evaluation index (F _occlusion / A) in the existing steel sheet pile of the first formula group G1 is 1.4, and the economic evaluation index (A ₀ / Ze) The lower limit is 0.0766.

As shown in Table 1, the steel sheet pile of the first example is included in the first formula group G1 because the section modulus Ze is 2134 cm ³ / m, and each limit line G1a to G1g of the first formula group G1 (See FIG. 11).
As shown in FIG. 18, the workability evaluation index (F _occlusion / A) of the steel sheet pile of the first example set to the cross-sectional shape of Table 1 is 0.94, and the economic evaluation index (A ₀ / Ze) Was 0.0734. In other words, the steel sheet pile of the first example is smaller than the lower limit (0.0766) of the economic evaluation index (A ₀ / Ze) of the existing steel sheet pile in terms of economy, and is compared with the existing steel sheet pile of the first example. The performance is improved by about 4%. Moreover, in the workability, among the existing steel sheet piles, the economic evaluation index (A ₀ / Ze) is the lower limit value of the workability evaluation index (F _occlusion / A) of the existing steel sheet pile, which is the lower limit value (0.0766). .40, the performance of the first embodiment with respect to the existing steel sheet pile is improved by about 33%.

Moreover, the workability evaluation index (F _blockage / A) of the steel sheet pile of the first example is 0.94, and the steel sheet pile of the first example and the workability evaluation index (F _blockage / A) are the same (0. 94) When compared with the lower limit (0.0884) of the economic evaluation index (A ₀ / Ze) of the existing steel sheet pile, the performance of the first embodiment with respect to the existing steel sheet pile is improved by about 17%.

(Second embodiment)
The second embodiment is an example of a steel sheet pile included in the second formula group G2 (see FIG. 20) in which the section modulus Ze shown in FIG. 19 is in the range of 2300 <Ze ≦ 3400 cm ³ / m (equation (16)). . In this 2nd Example, it is a Z-shaped steel sheet pile which makes a pair by fitting a joint and making it into a hat shape, and each dimension is shown in FIG. In addition, as shown in FIG. 20, the lower limit value of the economical evaluation index (A ₀ / Ze) of the existing steel sheet pile compared with this cross-sectional shape is 0.0713, and the economic evaluation index (A ₀ / Ze) However, the lower limit of the workability evaluation index (F _occlusion / A) of the existing steel sheet pile at 0.0713 is 1.04.

As shown in Table 2, the steel sheet pile of the second embodiment is included in the second formula group G2 because the section modulus Ze is 3057 cm ³ / m, and each limit line G2a to G2h of the second formula group G2 is included. (See FIG. 12).
As shown in FIG. 20, the workability evaluation index (F _occlusion / A) of the steel sheet pile of the second example set to the cross-sectional shape of Table 2 is 0.68, and the economic evaluation index (A ₀ / Ze) Was 0.0643. That is, the steel sheet pile of the second embodiment is smaller than the lower limit (0.0713) of the economic evaluation index (A ₀ / Ze) of the existing steel sheet pile in terms of economy, and is compared with the existing steel sheet pile of the second embodiment. The performance is improved by about 10%. Moreover, in workability, among the existing steel sheet piles, 1 is the lower limit value of the workability evaluation index (F _blockage / A) of the existing steel sheet piles where the economic evaluation index (A ₀ / Ze) is the lower limit value (0.0713). .04, the performance of the second embodiment with respect to the existing steel sheet pile is improved by approximately 35%.

Moreover, the workability evaluation index (F _blockage / A) of the steel sheet pile of the second example is 0.68, and the steel sheet pile of the second example and the workability evaluation index (F _blockage / A) are the same (0. 68), compared with the lower limit (0.0789) of the economic evaluation index (A ₀ / Ze) of the existing steel sheet pile, the performance of the second embodiment with respect to the existing steel sheet pile is improved by about 19%.

(Third embodiment)
The third embodiment is an example of a steel sheet pile included in the third formula group G3 (see FIG. 22) in which the section modulus Ze shown in FIG. 21 is in the range of 3400 cm ³ / m <Ze shown in formula (17). The third embodiment is a Z-shaped steel sheet pile which is a set of two pieces fitted with a joint to form a hat shape, and the dimensions are shown in FIG. In the third embodiment, H / t> 39. In addition, as shown in FIG. 22, the lower limit value of the economic evaluation index (A ₀ / Ze) of the existing steel sheet pile compared with this cross-sectional shape is 0.0602, and the economic evaluation index (A ₀ / Ze) However, the lower limit of the workability evaluation index (F _occlusion / A) of the existing steel sheet pile at 0.0602 is 0.52.

As shown in Table 3, the steel sheet pile of the third example is included in the third formula group G3 because the section modulus Ze is 4466 cm ³ / m, and each limit line G3a to G3f of the third formula group G3 is included. (See FIG. 13).
As shown in FIG. 22, the workability evaluation index (F _occlusion / A) of the steel sheet pile of the third example set to the cross-sectional shape of Table 3 is 0.49, and the economic evaluation index (A ₀ / Ze) Was 0.0507. In other words, the steel sheet pile of the third embodiment is smaller than the lower limit (0.0602) of the economic evaluation index (A ₀ / Ze) of the existing steel sheet pile in terms of economy, and is compared with the existing steel sheet pile of the third embodiment. The performance is improved by about 16%. Moreover, in workability, among the existing steel sheet piles, ₀ is the lower limit value of the workability evaluation index (F _occlusion / A) of the existing steel sheet pile in which the economic evaluation index (A ₀ / Ze) is the lower limit value (0.0602). .52, the performance of the third embodiment relative to the existing steel sheet pile is improved by about 5%.

Moreover, the workability evaluation index (F _blockage / A) of the steel sheet pile of the third example is 0.49, and the steel sheet pile of the third example and the workability evaluation index (F _blockage / A) are the same 0.49. When compared with the lower limit (0.0609) of the economic evaluation index (A ₀ / Ze) of the existing steel sheet pile, the performance of the third embodiment with respect to the existing steel sheet pile is improved by about 17%.

(Fourth embodiment)
The fourth example is an example of a steel sheet pile included in the third formula group G3 (see FIG. 24) in which the section modulus Ze shown in FIG. 23 is in the range of 3400 cm ³ / m <Ze shown in formula (17). In this 4th Example, it is a Z-shaped steel sheet pile which makes a pair by fitting two joints and each dimension is shown in FIG. In the fourth embodiment, a constraint condition of H / t <39 is provided. In addition, as shown in FIG. 24, the lower limit value of the economical evaluation index (A ₀ / Ze) of the existing steel sheet pile compared with this cross-sectional shape is 0.0602, and the economic evaluation index (A ₀ / Ze) However, the lower limit of the workability evaluation index (F _occlusion / A) of the existing steel sheet pile at 0.0602 is 0.52.

As shown in Table 4, the steel sheet pile of the fourth embodiment has a section modulus Ze of 4916 cm ³ / m, and thus is included in the third formula group G3, and each limit line G3a to G3f of the third formula group G3. (See FIG. 13).
As shown in FIG. 24, the workability evaluation index (F _occlusion / A) of the steel sheet pile of the fourth example set to the cross-sectional dimensions of Table 4 is 0.43, and the economic evaluation index (A ₀ / Ze) Was 0.0562. In other words, the steel sheet pile of the fourth example is smaller than the lower limit (0.0602) of the economic evaluation index (A ₀ / Ze) of the existing steel sheet pile in terms of economy, and is compared with the existing steel sheet pile of the fourth example. The performance is improved by about 7%. Moreover, in terms of workability, the workability evaluation index (F _occlusion / A) of the steel sheet pile of the fourth example in which the economic evaluation index (A ₀ / Ze) is the lower limit (0.0602) among the existing steel sheet piles. It is smaller than the lower limit of 0.52, and the performance of the fourth embodiment with respect to the existing steel sheet pile is improved by about 18%.

Moreover, the workability evaluation index (F _blockage / A) of the steel sheet pile of the fourth example is 0.43, and the steel sheet pile of the fourth example and the workability evaluation index (F _blockage / A) are the same 0.43. When compared with the lower limit (0.0625) of the economic evaluation index (A ₀ / Ze) of the existing steel sheet pile, the performance of the third embodiment with respect to the existing steel sheet pile is improved by about 10%.

As mentioned above, although embodiment of the steel sheet pile by this invention was described, this invention is not limited to said embodiment, In the range which does not deviate from the meaning, it can change suitably.

For example, in the above-described embodiment, the conditions for calculating the blocking resistance F _blocking are μ = 0.27, ν = 3.3, γ = 1.8 × 10 ⁻⁸ kN / mm ³ , Z _v = 15000 mm. , N value 20 and relative density Dr = 80% will be described as an example. FIGS. 11 to 13 show respective formula groups (first formula group G1, second formula group G2, third formula group G3) determined under the above conditions. ), The limit areas of the workability evaluation index C and the economic evaluation index E are set by these formula groups, and this is used as the performance range of the steel sheet pile. However, the scope of application of the present invention is not limited to this. For example, the N value which is the ground condition in the calculation of the blockage resistance F _blockage is set to a different value, and the steel sheet pile is based on each formula group determined in the calculation conditions associated therewith. A performance range may be defined.

Therefore, in the following, as an example, in each of the case where the N value is 1 and the case where the N value is 50, formula groups in each case (first formula group G1, second formula group G2, third formula group G3) The limit areas of the workability evaluation index C and the economic evaluation index E when the N value is 1 and 50 are illustrated.

(When N value = 1)
As conditions for calculating the blocking resistance F _blocking , μ = 0.27, ν = 2.0, γ = 1.8 × 10 ⁻⁸ kN / mm ³ , Z _v = 15000 mm, N value 1, relative density Dr = 20%. Formula group G at this time is as shown in Table 5 below. FIGS. 26 to 28 illustrate a plurality of limit lines constituting each of the expression groups G1 to G3 shown in Table 5. Each expression is similar to FIGS. 11 to 13 described in the above embodiment. The performance range of the steel sheet pile shown by a group is shown.
Under these conditions, the occlusion resistance F _occlusion of the steel sheet piles of Examples 1 to 3 is calculated, and the workability evaluation index (F _occlusion / A) and the economic evaluation index (A ₀ / Ze) of Examples 1 to 3 are calculated. Values are plotted in FIGS. 26-28, respectively. 26 to 28, in the case of N value = 1, the steel sheet piles of Examples 1 to 3 are within the performance range of the steel sheet piles indicated by the respective formula groups as in the case of N value = 20. Even if the ground conditions change, the shape of the sheet pile does not change, and it can be a cross section that is superior in terms of workability and economy compared to existing steel sheet piles.

(N value = 50)
As the conditions for calculating the blocking resistance F _blocking , μ = 0.27, ν = 5.1, γ = 1.8 × 10 ⁻⁸ kN / mm ³ , Z _v = 15000 mm, N value 50, relative density Dr = 100%. The formula group G at this time is as shown in Table 6 below. FIGS. 29 to 31 illustrate a plurality of limit lines constituting each of the expression groups G1 to G3 shown in Table 6. Each expression is similar to FIGS. 11 to 13 described in the above embodiment. The performance range of the steel sheet pile shown by a group is shown.
Under these conditions, the occlusion resistance F _occlusion of the steel sheet piles of Examples 1 to 3 is calculated, and the workability evaluation index (F _occlusion / A) and the economic evaluation index (A ₀ / Ze) of Examples 1 to 3 are calculated. Values are plotted in FIGS. 29-31, respectively. 29 to 31, when the N value = 50, as in the case where the N value = 20, the steel sheet piles of Examples 1 to 3 are within the performance range of the steel sheet pile shown by each formula group. Even if the ground conditions change, the shape of the sheet pile does not change, and it can be a cross section that is superior in terms of workability and economy compared to existing steel sheet piles.

As shown in FIGS. 26 to 28 and 29 to 31, the performance range of the steel sheet pile is specified from the plurality of limit lines constituting the formula group G even when the condition for calculating the closing resistance F _closing is changed. It can be seen that a steel sheet pile having a cross-sectional shape excellent in at least one of the workability and the economical efficiency can be provided. That is, it can be seen that the technology of the present invention can be applied under all ground conditions.

Further, for example, in the above-described embodiment, as described with reference to FIG. 14 and the like, it is set so as to satisfy the range of (section height H / minimum plate thickness t) ratio <39. It is not limited to providing such a restriction. Specifically, when the ground condition is an N value ≦ 35, it may be set so as to satisfy a range of (section height H / minimum plate thickness t) ratio ≦ 45. Below, the reason is demonstrated with reference to the graph about the full-scale construction test at the time of setting to the range of (section height H / minimum sheet thickness t) ratio <= 45.

FIG. 32 is a graph showing the ground conditions in the full-scale construction test, and represents the N value depth distribution. FIGS. 33 to 35 are graphs showing the total width difference before and after the casting of a steel sheet pile having an effective width of 1270 mm or more. Each graph has a ratio (section height H / minimum sheet thickness t) of 39, 42, 45. The case is shown.

As shown in FIG. 32, in the ground conditions for the actual construction test here, the N value is 35 at a depth of 8 m, and the N value is 35 or less in a shallower layer. Further, as shown in FIGS. 33 to 35, the ground having an N value of 35 or less (a layer shallower than a depth of 8 m) in any steel sheet pile having a (section height H / minimum sheet thickness t) ratio of 39, 42, and 45. It can be seen that the total width difference is within the range of -5 mm to 10 mm which is the JIS production tolerance. In other words, if the ground condition is N value ≦ 35, the (section height H / minimum sheet thickness t) ratio of the steel sheet pile can be set in the range of 45 or less.

As described above with reference to FIGS. 32 to 35, the range setting of the (sheet height H / minimum sheet thickness t) ratio of the steel sheet pile may be suitably set according to the ground conditions. It is not limited to the range of (section height H / minimum plate thickness t) ratio <39 set in the form.

Moreover, the steel sheet pile according to the present invention may be manufactured hot. In the manufacture of hot steel sheet piles, it is possible to make a difference in sheet thickness within the cross section of the steel sheet pile, making it possible to increase the thickness of the section where the cross section is easily deformed, and to reduce the cross section deformation at the time of placing. It can suppress more effectively and can suppress an increase in placing resistance.

In addition, it is possible to appropriately replace the constituent elements in the above-described embodiments with known constituent elements without departing from the spirit of the present invention.

The present invention can be applied to steel sheet piles used as retaining walls, revetments, etc. in the civil engineering and construction fields.

Claims

It is a steel sheet pile constituting the wall body,
A first flange and a second flange that are substantially parallel to the neutral axis of the wall body, are symmetrically positioned across the neutral axis and are parallel to each other, and a web connecting the first flange and the second flange;
In the steel sheet pile with one unit between the midpoints of the first flanges adjacent to each other or the second flanges in the wall body,
When two flanges provided at both ends of one unit in the steel sheet pile are second flanges,
A joint for fitting steel sheet piles to each other is formed at the end of the second flange,
The length between the fitting centers of a pair of joints formed at the ends of the two second flanges is an effective width, the effective width is 1270 mm or more, and the section modulus Ze is in a range of 1700 ≦ Ze ≦ 2300 cm 3 / m. Satisfactory steel sheet pile,
The unit volume weight γ of the soil of the target ground is 1.8 × 10 −8 kN / mm 3 , the friction coefficient μ between the soil and the steel sheet pile is tan 15 °, and the passive earth pressure coefficient ν of Rankine is

When the relative density Dr is 80%, the N value is 20, and the placement depth Z ν is 15000 mm,
A steel sheet pile, wherein the workability evaluation index C and the economic evaluation index E represented by the following formulas (18) and (19) satisfy any of the following formulas (20) to (23): .
C = F obstruction / A (18)
E = A 0 / Ze (19)
0.11 ≦ C ≦ 1.00 and −0.0208 × C + 0.0809 ≦ E ≦ 0.0884 (20)
1.00 <C ≦ 1.20 and −0.0208 × C + 0.0809 ≦ E ≦ −0.03 × C + 0.1186 (21)
1.20 <C ≦ 1.40 and 0.0560 ≦ E ≦ −0.03 × C + 0.1186 (22)
1.40 <C ≦ 1.80 and 0.0560 ≦ E ≦ 0.0766 (23)
However, F occlusion : the following formulas (6), (3) ′, (4), (14), (12), (13), (1) ′ and (2) ′ and (7) or (7) Blocking resistance (kN / sheet) calculated based on ', A: sectional area (cm 2 / sheet), A 0 : sectional area (cm 2 / m) per 1 m width in the wall direction at the time of wall formation , Wf: width (mm) of the first flange, H: cross-sectional height (mm) which is a distance between the first flange and the second flange in a direction orthogonal to the neutral axis, θ: the web and the second It is a web angle (°) that is a complementary angle of the angle formed by the flange.
It is a steel sheet pile constituting the wall body,
A first flange and a second flange that are substantially parallel to the neutral axis of the wall body, are symmetrically positioned across the neutral axis and are parallel to each other, and a web connecting the first flange and the second flange;
In the steel sheet pile with one unit between the midpoints of the first flanges adjacent to each other or the second flanges in the wall body,
When two flanges provided at both ends of one unit in the steel sheet pile are second flanges,
A joint for fitting steel sheet piles to each other is formed at the end of the second flange,
The length between the fitting centers of a pair of joints formed at the ends of the two second flanges is an effective width, the effective width is 1270 mm or more, and the section modulus Ze is in a range of 2300 <Ze ≦ 3400 cm 3 / m. Satisfactory steel sheet pile,
The unit volume weight γ of the soil of the target ground is 1.8 × 10 −8 kN / mm 3 , the friction coefficient μ between the soil and the steel sheet pile is tan 15 °, and the passive earth pressure coefficient ν of Rankine is

When the relative density Dr is 80%, the N value is 20, and the placement depth Z ν is 15000 mm,
The steel sheet pile, wherein the workability evaluation index C and the economic evaluation index E represented by the following formulas (18) and (19) satisfy any of the following formulas (24) to (28): .
C = F obstruction / A (18)
E = A 0 / Ze (19)
0.12 ≦ C ≦ 0.66 and −0.0225 × C + 0.066 ≦ E ≦ 0.08 (24)
0.66 <C ≦ 0.85 and −0.0225 × C + 0.066 ≦ E ≦ −0.0306 × C + 0.0997 (25)
0.85 <C ≦ 0.89 and 0.0469 ≦ E ≦ −0.0306 × C + 0.0997 (26)
0.89 <C ≦ 1.04 and 0.0469 ≦ E ≦ 0.0077 × C + 0.0793 (27)
1.04 <C ≦ 1.20 and 0.0469 ≦ E ≦ 0.0795 (28)
However, F occlusion : the following formulas (6), (3) ′, (4), (14), (12), (13), (1) ′ and (2) ′ and (7) or (7) Blocking resistance (kN / sheet) calculated based on ', A: sectional area (cm 2 / sheet), A 0 : sectional area (cm 2 / m) per 1 m width in the wall direction at the time of wall formation , Wf: width (mm) of the first flange, H: cross-sectional height (mm) which is a distance between the first flange and the second flange in a direction orthogonal to the neutral axis, θ: the web and the second It is a web angle (°) that is a complementary angle of the angle formed by the flange.
It is a steel sheet pile constituting the wall body,
A first flange and a second flange that are substantially parallel to the neutral axis of the wall body, are symmetrically positioned across the neutral axis and are parallel to each other, and a web connecting the first flange and the second flange;
In the steel sheet pile with one unit between the midpoints of the first flanges adjacent to each other or the second flanges in the wall body,
When two flanges provided at both ends of one unit in the steel sheet pile are second flanges,
A joint for fitting steel sheet piles to each other is formed at the end of the second flange,
The effective width is the length between the fitting centers of a pair of joints formed at the tips of the two second flanges, the effective width is 1270 mm or more, and the section modulus Ze satisfies the range of 3400 cm 3 / m <Ze. A steel sheet pile,
The unit volume weight γ of the soil of the target ground is 1.8 × 10 −8 kN / mm 3 , the friction coefficient μ between the soil and the steel sheet pile is tan 15 °, and the passive earth pressure coefficient ν of Rankine is

When the relative density Dr is 80%, the N value is 20, and the placement depth Z ν is 15000 mm,
The steel sheet pile, wherein the workability evaluation index C and the economic evaluation index E represented by the following formulas (18) and (19) satisfy any of the following formulas (29) to (31): .
C = F obstruction / A (18)
E = A 0 / Ze (19)
0.13 ≦ C ≦ 0.36 and −0.0237 × C + 0.0538 ≦ E ≦ 0.0642 (29)
0.36 <C ≦ 0.52 and −0.0237 × C + 0.0538 ≦ E ≦ −0.025 × C + 0.0732 (30)
0.52 <C ≦ 0.75 and −0.0237 × C + 0.0538 ≦ E ≦ 0.0602 (31)
However, F occlusion : the following formulas (6), (3) ′, (4), (14), (12), (13), (1) ′ and (2) ′ and (7) or (7) Blocking resistance (kN / sheet) calculated based on ', A: sectional area (cm 2 / sheet), A 0 : sectional area (cm 2 / m) per 1 m width in the wall direction at the time of wall formation , Wf: width (mm) of the first flange, H: cross-sectional height (mm) which is a distance between the first flange and the second flange in a direction orthogonal to the neutral axis, θ: the web and the second It is a web angle (°) that is a complementary angle of the angle formed by the flange.
The ratio H / t between the cross-sectional height H and the minimum plate thickness t which is the minimum plate thickness among the plate thickness of the first flange excluding the joint, the plate thickness of the web, or the plate thickness of the second flange is 39. The steel sheet pile according to any one of claims 1 to 3, wherein the steel sheet pile is set so as to satisfy a range of less than.
When the N value of the target ground is 35 or less,
The ratio H / t between the sectional height H and the minimum plate thickness t, which is the minimum plate thickness of the first flange plate thickness, web plate thickness, or second flange plate thickness excluding the joint, is 45. The steel sheet pile according to any one of claims 1 to 3, wherein the steel sheet pile is set so as to satisfy the following range.
The first flange width of the steel sheet pile, geometric constraints determined from the web angle,
The steel sheet pile according to any one of claims 1 to 5, wherein a structural constraint defined by a width-thickness ratio according to a steel material yield strength for preventing buckling is set.
The steel sheet pile according to any one of claims 1 to 6, wherein the steel sheet pile is manufactured hot.
The steel sheet pile is
A first flange and a pair of webs extending from both ends of the first flange, and a pair of second flanges having a joint at a tip extending in parallel with the first flange on the opposite side of the web from the first flange. The steel sheet pile according to any one of claims 1 to 7, which is a hat-shaped hat-shaped steel sheet pile.
The steel sheet pile is
In a Z-shaped steel sheet pile made up of a pair of parallel flanges having joints at opposite ends extending in opposite directions to both ends of the web, a pair of Zs formed by fitting the joints into a hat shape A steel sheet pile,
In the set of two Z-shaped steel sheet piles, both flanges on the side where the joint is fitted are used as the first flange, and both flanges on the side where the joint is not fitted are used as the second flange. The steel sheet pile according to any one of claims 1 to 7.