JPS6138100A - Method of filling construction of secondary lining concrete in shielding construction - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION In shield construction, the filling rate of the secondary lining concrete is an important point in controlling the roll thickness.

Particularly in the case of steel segments, a specified amount of concrete enters K<< which directly affects the quality of the finished shape.

The main girders of the segments protrude inward, so when concrete is poured, the air at the bottom escapes to the top, but it is difficult for the air at the top to escape.Especially near the top, the air between the main girders flows through the girders. This is dangerous because the air between the flanges remains on the back side of the segment because there are many 7-flange flanges in the case of steel segments, and the concrete solidifies, which is dangerous. This method has disadvantages such as an increase in the ratio.

In view of these drawbacks, the present invention aims to push out the air on the side where the top end of the segment is being cast, and to push out the air on the side where the top end of the segment has not yet been cast. This invention relates to a method for filling secondary lining concrete in shield construction, with the aim of making it possible to reliably and airtightly place extruded concrete.

Now, to describe an embodiment for achieving the above-mentioned purpose, after the completion of the primary segment burying work, the main girder or 7 langes (2) k which are formed to protrude inward from the concrete segment or steel segment (1). On the other hand, segment) (1
The U-shaped pipe (3) is fitted and fixed so that the open end (3a) is in contact with the inner surface of the pipe.

When fixing the U-shaped pipe (3) and the main girder or flange (2), the space (3b) K in the center of the U-shaped pipe (3) is
The main girder flange (2) is fitted, and the open end (3a) of the U-shaped pipe (3) is positioned very close to the inner surface (1a) of the segment) (11), and the U-shaped pipe (3) and the main Fix it to the girder flange (2) as appropriate.

The U-shaped pipe (3) should be installed above the upper half of the shield (4), especially near the top.

This is because the air in the void formed near the lower half and sides of the shield (4) is easily pushed upwards by concrete pouring and does not remain, but near the top of the shield (4) the air in the void formed near the main girder or 7
This is because the lateral movement is prevented by the lunge (2) and the like and it remains in the gap.

In this application, after preparing as described above, when concrete is poured from the bottom, the air in the voids in the formwork is removed from the concrete.)
(The concrete (5) is pushed out horizontally or upwardly by 51K, and the space between the segment and the formwork is filled with concrete (5).

However, as you go to the top, the main girder 7 lunge (2) becomes a wall surface! i (The air in 61 is compressed by concrete (5) and its volume is reduced, but it does not shrink beyond a certain level, so it is concrete) (5> is not placed).

Therefore, as mentioned above, in this application, the U-shaped pipe (3) is provided so that both sides of the main girder flange (2) are connected. It is discharged through the hole of the U-shaped pipe (3) as shown by the arrow, and in this way it is sequentially discharged from the main girder flange (2).
(The air moves to the inner surface of 11 and finally escapes through the U-shaped pipe (3), passing through the segments and exhausting the air inside.) It can be poured without leaving any residue.

Example: After 53 spans had passed after the start of secondary lining, the filling rate of the U-shaped pipe was improved and the voids at the top were investigated.

and Uo = 4.713> U (2α) = 3. . 90, and at a significance level (risk rate) of 1%, the filling rate was improved by using the U-shaped pipe.

From the above results, the gap at the top was reduced by one order from the unit to the line, and the implant filling rate increased by about 2%. This was achieved by eliminating the air at the top.

As described above, after constructing the Kel segment in the shield work, the opening in the main girder near the top end is provided with counter pressure in the longitudinal direction of the top end of the segment, and the opening approaches the inner surface of the segment and the center of the curved part. The main girder is fitted to the main girder, an appropriate number of U-shaped pipes are installed, and then concrete is poured between the segments and the inner formwork, so it is possible to achieve the desired purpose. be.

[Brief explanation of drawings]

FIG. 1 is a sectional view of the shield, FIG. 2 is an enlarged sectional view of section B in FIG. 1, and FIG. 3 is a sectional view taken along line CC in FIG.

Claims (1)

[Claims] (1) After constructing the segment during shield construction, the opening of the main girder near the top end of the segment is placed in the longitudinal direction, and the opening approaches the inner surface of the segment, and the main girder is fitted into the center of the curved part. A secondary lining concrete filling method in shield construction, characterized by installing an appropriate number of U-shaped pipes and then pouring concrete between the segments and the inner formwork.