JPH0243410A - Method for building vertical hole on underground structure - Google Patents

Abstract

PURPOSE:To build a vertical hole at an approximately same time when hardening filler is cured, by inserting a pipe applied by antifriction agent around it, into unhardened hardening filler filled in drill trench, then pulling this pipe out after hardening. CONSTITUTION:In the process that hardening filler 2 is filled in drill trench 1 and is replaced by stabilizing solution to construct an underground structure, a pipe 4 is inserted in the hardening filler 2 before it is hardened with an inserting/pulling machine 3. The pipe 4 is used by a steel pipe or the like having the sharp shape at the point, which is applied by antifriction agent around it beforehand, and is inserted vertically, as unit pipes with required lengths are connected, in turn, according to the depth of drill trench 1. After the hardening filler 2 is hardened, the pipe 4 is pulled out by the inserting/pulling machine 3 and a vertical hole 5 is constructed. Therefore, at an approximately same time when hardening filler is cured, a vertical hole can be constructed with a low cost.

Description

Detailed Description of the Invention "Field of Industrial Application" This invention is a method of filling an excavated trench such as an underground continuous wall with a hardened filler such as concrete, solidified mud, or low-strength concrete and placing it with a stabilizing liquid. This relates to a construction method for constructing underground structures that involves constructing a vertical hole at the bottom of an excavation trench for grouting, etc.

``Prior art and problems to be solved by the invention'' Conventionally, in the construction method of filling an excavated trench of an underground continuous wall with hardened filler and replacing it with a stabilizing liquid, When constructing a vertical hole, there is a method of constructing a vertical hole by performing boring after the filler has hardened, and before placing the hardened filler, the pipe is supported in a frame built into the excavation trench and installed in the specified position. There is a method in which the pipe is then turned into a vertical hole by filling the excavated trench with hardened filler.

However, in the former method, poling is performed after the hardened filler has hardened and has been cured for a sufficient number of days.
As the construction period becomes later, the construction cost per unit length of the vertical hole becomes higher and the construction time becomes longer.Moreover, when low-strength concrete is used as a hardened filler, the diameter of the poling hole becomes large, and the area around the hole wall increases. There were drawbacks, such as damage to the hardened filler, which led to deterioration in the quality of the structure.

In addition, in the latter method, a frame is required to maintain the pipe in place against the flow pressure of the hardened filler, and the construction is not easy because it incorporates a frame to support the upper pipe. There were problems such as it being uneconomical as it could only be withdrawn.

"Means for Solving the Problems" In order to solve the above-mentioned conventional problems, the present invention involves inserting a pipe whose periphery is coated with an anti-friction agent in advance into a hardened filler filled in an excavated trench. By pulling out the tube after curing the hardened filler, it is possible to construct a vertical hole at low cost almost simultaneously with curing the hardened filler without having to install a polling tool or support frame for the tube. In addition to shortening the construction period, pipes can be pulled out and reused without being buried, and even if low-strength concrete is used, it is possible to create a rational vertical structure that does not cause quality deterioration of the underground structure. This project proposes a method for constructing holes.

"Embodiments" Below, embodiments of the present invention shown in the drawings will be described.
As shown in Figure 1, a hardened filler 2 such as concrete, solidified mud, or low-strength concrete is filled to improve excavated trenches such as underground continuous walls, and is replaced with a stabilizing liquid. In the process of constructing the medium structure, the tube 4 is inserted into the hardened filler 2 before hardening by inserting and pulling out a3 as shown in FIG.

The pipe 4 is made of a steel pipe with a sharp tip, the circumference of which has been coated with an anti-friction agent in advance, and is inserted vertically into the excavation groove 1 while sequentially adding unit pipes of required length according to the depth of the excavation groove 1.

After that, as shown in FIG. 3, the hardened filler 2 is cured and cured for a required number of days, and then the tube 4 is pulled out by the insertion/pulling machine 3 as shown in FIG. Do a・A.

In this case, since negative pressure is generated in the vertical hole 5 as the tube 4 is pulled out, an opening 6 is provided at the tip of the tube 4 as shown in FIG. 6, and this opening 6 is closed when the tube 4 is inserted. By pulling the stopper 7 upward using a connecting member 8 such as a rod or wire, the vertical hole 5 is communicated with the atmosphere through the opening 6 and the inside of the pipe 4, thereby preventing negative pressure.

In addition, insertion/extraction! For a3, use one that has sufficient operating force for inserting and withdrawing the tube 4, has a vertical adjustment function during insertion, and is it desirable to be able to share insertion and withdrawal. It is also possible to use a common insertion and extraction machine.

Furthermore, as the hardened filler 2 used in this invention, it is preferable to use one with low strength for boat fishing, but even if it is low strength or high strength, it is necessary to start setting in order to facilitate insertion of the tube 4. Late or necessary.

"Effects of the Invention" As described above, according to the present invention, a pipe whose periphery is coated with an antifriction agent in advance is inserted into a hardened filler filled in an excavated groove, and the hardened filler is cured. Since the rear tube is pulled out,
Vertical holes can be constructed at low cost almost simultaneously with curing of the hardened filler without having to install polling holes or support frames for pipes as in the past, shortening the construction period and making it possible to bury the pipes. To be economical in that it can be pulled out and reused without leaving any residue, and to reliably construct a vertical hole without causing quality deterioration of underground structures such as damage to the hole wall even when using low-strength concrete. I can do it.

Furthermore, since an anti-friction agent is applied to the circumference of the tube in advance, the resistance during insertion and withdrawal is reduced, making it possible to easily insert and withdraw the tube.

Furthermore, the diameter of the vertical hole can be arbitrarily changed depending on the purpose by changing the pipe diameter, and the depth of the vertical hole can be freely adjusted by adding pipes.

[Brief explanation of the drawing]

1 to 5 are vertical sectional front views showing the construction process of the present invention, and FIG. 6 is a partial vertical sectional front view showing the tip structure of the pipe used in the present invention. 1. Excavation groove, 2. Hardened filler, 3. Insertion/extraction machine, 4. Pipe, vertical hole. Figure 6

Claims (1)

[Claims] 1) In an underground structure construction method in which a hardened filler such as concrete, solidified mud, or low-strength concrete is filled into an excavated trench such as an underground continuous wall and replaced with a stabilizing liquid, an anti-friction agent is applied to the surrounding area in advance. Construction of a vertical hole in an underground structure characterized by inserting the coated pipe into a hardened filler before hardening filled in an excavation trench, and pulling out the pipe after the hardened filler hardens and cures. Construction method.