JPS6140820B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for placing foot protection concrete, and in particular, at the final stage of placing foot protection concrete in an excavated hole, the concrete remaining in a tremie pipe is measured at its top. while pressing down with the weight of the liquid using a water stop bag containing the liquid,
To block interference between liquid and concrete and push down the top end of residual concrete in a tremie pipe to a predetermined position in a state where the liquid does not adversely affect the concrete.

Piles made of steel pipes, steel columns, etc. are erected in the excavated hole.
When cementing this with concrete, place the tremie pipe 2 facing the bottom of the excavation hole 3 as shown in Figure 1.
Place foot protection concrete 1. At the final stage of pouring, when a predetermined amount of concrete has been poured into the tremie pipe 2, concrete 1' remains inside the tremie pipe 2, particularly as shown in FIG. 1A. This is caused by the difference in specific gravity between the muddy water 9 in the excavated hole 3 and the concrete 1' in the tremie pipe 2, and the adhesion resistance between the concrete 1' and the tremie pipe 2. As a result, the top of the poured concrete 1 and concrete 1' in tremie pipe 2.
There is a difference in height h between the top and the top. If the length of the pile is 100 m, the height h will be 50 m.

Conventionally, in order to push up the concrete inside the tremie pipe, a liquid such as water or muddy water is directly injected from the upper end of the tremie pipe, and the concrete is pushed down by its weight. Similarly, there was a method of pressing down with liquid 7. In the method of directly injecting liquid, the concrete adhering to the inside of the tremie pipe 2 is washed away by the liquid, and the muddy water that has deteriorated and gelled due to the alkaline components of the concrete and the concrete bones adhering to the inside of the pipe are removed. The materials are mixed to form a slime S. It often got mixed into the concrete that had already been placed and was deposited on the upper surface of the concrete. Therefore, if this slime-like material mixes into concrete, it will inevitably reduce the strength of the concrete, and if it accumulates on the top of the concrete, it will become difficult to use next time to form the main body such as a wall. There was a drawback that the continuous portion between the poured concrete and the foot protection concrete became brittle due to the deposits. In addition, even when a special stopper is used, the stopper must be moved downward one after another, so it cannot be brought into close contact with the tremie tube, so there is a gap between the stopper and the tremie tube, and the liquid ends up It is not possible to block concrete interference. Therefore, to a lesser extent, the same disadvantages as the above-mentioned method of directly injecting liquid existed.

Furthermore, these conventional methods also have the disadvantage that the relationship between the height of the concrete top in the tremie pipe and the poured concrete top must be measured separately from the liquid injection.

Therefore, this invention was provided in order to eliminate these drawbacks, and its purpose is to increase the strength of foot-protected concrete by blocking interference between the concrete and the liquid used to push it down in the tremie pipe. The purpose of this is to measure the height of the top of the concrete while pushing down the concrete in the tremie pipe, and to prevent the generation of slime-like precipitates on the top surface of the concrete. The object is to accurately grasp the pressed down position.

That is, this invention, as in the embodiment shown in FIG.
Add a predetermined amount of concrete 1 to the tremie pipe 2
After inserting the concrete into the excavated hole 3 through the tremie pipe 2, insert the waterproof bag 4 into the tremie pipe 2 from its upper end, and measure the top of the concrete 1' inside the tremie pipe 2 at the same time or before or after the insertion. Measurement weight 5
Insert it into the waterproof bag 4 while connected to the string 6,
Separately, a liquid 7 such as water or muddy water is injected into the water-stop bag 4, and the tremie tube 2 is inserted with the measuring weight 5.
The present invention relates to a method of pouring concrete for pouring concrete, which is characterized in that the remaining concrete 1' in the tremie pipe 2 is pushed down by the weight of the liquid 7 while measuring the top of the concrete 1' inside.

Next, the present invention will be explained based on the embodiment shown in FIG.

Foot protection concrete 1 is poured into the excavated hole 3 via the tremie pipe 2. In the excavated hole 3, for example, a steel pile 8, which serves as a reference pile for constructing a continuous inner wall, is built. A part of the foot protection concrete 1 that has been poured remains in the tremie pipe 2. As mentioned above, this is mainly caused by the difference in specific gravity between the muddy water 9 in the excavated hole 3 and the residual concrete 1' in the tremie pipe 2, and the adhesion resistance between the concrete 1' and the tremie pipe 2. It is.

Therefore, the water-stop bag 4 is inserted into the tremie tube 2 from its upper end. Water stop bag 4 is made of vinyl chloride resin,
It is a flexible and waterproof bag made of polyethylene resin or the like, and preferably has a shape that matches the shape of the tremie tube 2. At the same time or before or after inserting the water-stop bag 4, a measuring weight 5 for measuring the top of the residual concrete 1' in the tremie pipe 2 is connected to the string 6, and the water-stop bag 4 is inserted into the water-stop bag. Insert within 4.

Before inserting the water stop bag 4 into the tremie tube 2, the measuring weight 5 is inserted into the water stop bag 4 in advance, and the inserted water stop bag 4 is inserted into the tremie tube 2. The measuring weight 5 also serves as a weight for inserting the water stop bag 4. The same applies when the water-stop bag 4 is inserted into the tremie tube 2 and the measuring weight 5 is inserted into the water-stop bag 4 at the same time. Further, when the water-stop bag 4 is inserted into the tremie tube 2 first, if an appropriate amount of liquid 7 is placed in the water-stop bag 4, this acts as a weight.

The string 6 connected to the measuring weight 5 at its tip may have a scale attached thereto and be read at the upper end of the excavated hole 3, or the string 6 may have a rear end wound around a drum. , it may be of a type that mechanically detects the extended length.

Then, a liquid 7 such as water or muddy water is injected into the water-stop bag 4. At this time, the weight of the liquid 7 is applied to the residual concrete 1' as much as possible through the bottom of the water-stop bag 4. The remaining concrete 1' is then pushed down by the liquid 7, and the concrete 1' is poured into the bottom of the excavated hole 3.

The remaining concrete 1' is pressed down by the liquid 7 while measuring the top position with the measuring weight 5 until the top reaches a predetermined position.
The predetermined position usually means the same height as the top of the foot protection concrete 1 cast at the bottom of the excavated hole 3, but it may be in another positional relationship. By pressing down to this predetermined position, the pouring of the foot protection concrete 1 is completed.

At the end of this process, the opening at the lower end of the tremie pipe 2 may protrude into the foot hardening concrete 1, as shown in FIG. 2, or may be at the top end of the concrete 1. In the latter case, as the top of the residual concrete 1' approaches the top of the foot protection concrete 1, the tremie pipe 2 is pulled up to the above position.

Next, pull up the string 6 to take out the measuring weight 5, close the top of the water stop bag 4 while keeping air in the top so that the water stop bag 4 does not sink, and close the water stop bag 4.
The tremie tube 2 is removed from the excavated hole 3 while still remaining inside. Thereafter, the water stop bag 4 is taken out from the tremie tube 2 and reused.

The order of taking out the measuring weight 5, removing the tremie tube 2, and taking out the water-stop bag 4 can be changed as appropriate. However, if the tremie tube 2 is removed with the water-stop bag 4 still inside, the water-stop bag 4 will be removed more easily than when the water-stop bag 4 is removed alone from the tremie tube 2 in the excavated hole 3 with the liquid 7 still inside. It is easy to remove and also protects the water stop bag 4. Further, the water stop bag 4 may be removed with the liquid 7 still inside, or
Conversely, it may be removed after the liquid 7 has been drained.

According to this invention, since the water-stop bag blocks the liquid from the concrete remaining in the tremie pipe, the liquid does not deteriorate or gel due to the alkaline components of the concrete, and the liquid is mixed with the concrete aggregate to form slime. There will be no condition. Therefore, it does not mix into the foot protection concrete and reduce its strength, nor does it accumulate on the top surface of the concrete, so the strength of the foot protection concrete is ensured, and
Next, the continuous part of the concrete poured on top of the foot protection concrete will also become stronger.

Further, according to the present invention, since the top of the remaining concrete can be constantly measured using a measuring weight, there is no possibility that the concrete will be pushed down too much and liquid will be mixed into the foot protection concrete from the opening at the lower end of the tremie pipe. do not have. Therefore, not only the strength of the concrete is ensured in this respect, but also
This facilitates the treatment of the foot protection concrete and the continuous portion of concrete poured thereon.

[Brief explanation of the drawing]

Figure 1 shows the conventional method of placing concrete for foot protection, A is an explanatory diagram of the remaining state of residual concrete, B is an explanatory diagram showing the conventional method for placing concrete for foot protection, and Figure 2 is the invention. FIG. 2 is an explanatory diagram showing an example of the method. In addition, in the figure, 1 is foot protection concrete, 1' is concrete in the tremie pipe, 2 is tremie pipe, and 3 is concrete.
4 is a water stop bag, 5 is a measuring weight, 6 is a string, and 7 is a liquid.

Claims (1)

[Claims] 1. After putting a predetermined amount of cemented concrete into the excavated hole through the tremie pipe, insert a water stop bag into the tremie pipe from its upper end, and measure the top of the concrete inside the tremie pipe at the same time or before or after the insertion. A measuring weight connected to a string is inserted into a water-stop bag, and a liquid such as water or muddy water is separately poured into the water-stop bag, and the measuring weight is connected to a string. A method for pouring concrete with foot protection, which comprises pressing down residual concrete in a tremie pipe by the weight of the liquid while measuring the top of the concrete in the tremie pipe.