JPS62228525A - Removal work of sheathing stressing material by drawing - Google Patents

Abstract

PURPOSE:To permit a stressing material to be drawn out with a low drawing force simply by a method in which a stressing material whose surface is covered with a synthetic resin film is penetrated to form a sheathing wall, and upon completion of construction up to the surface of the ground or of back filling, and the stressing material is pulled out. CONSTITUTION:All surface but a coupling portion 2 of a steel sheet pile 1 is covered with a synthetic resin film 3 with the aid of a water-soluble adhesive. Pits 4 are excavated in given places of the ground, a mud water solidifying liquid is confined in the pits 4, and sheet piles 1 are orderly penetrated and fixed. After the liquid is hardened, the ground between the pits 4 is excavated 5, a mud water solidifying liquid is confined in the pit, and sheet piles 1 are penetrated into the pit to form a continuous sheathing wall. The inside ground of the wall is excavated, a structure is constructed, and backfilling is ended. Afterwards, the sheet piles 1 are pulled out by an oil-pressure jack crane. Since the water of the mud water solidifying liquid permeates between the sheet piles 1 and the film 3 to fluidize the adhesive, the sheet piles 1 can be easily pulled out.

Description

[Detailed description of the invention] This invention enables the earth retaining stress material used in excavation work to be easily pulled out with low tensile force after excavating the inside of the earth retaining wall and completing the construction or backfilling of the structure. .

Conventional technology There are many types of earth retaining methods used in excavation construction, but the steel sheet pile method and the H-copper loss sheet pile method were used in the past.
The PIF construction method and the continuous underground wall construction method have been widely used as mountain retaining wall construction methods since about 2000, and continuous underground walls with high rigidity are frequently constructed in relatively deep excavations.

Recently, mud water solidification method and auger soil mixing method have been adopted for cut-and-cover construction in large urban areas as construction methods to minimize noise, vibration, groundwater drop, subgrade ground law, etc. that disturb the lives of residents around the construction site.

Moreover, even in these earth retaining methods, steel sheet piles and H-steel pile type steel are used as stress materials, and the stress materials are
At present, when the stress exceeds 500 m, it is buried even though it is no longer needed after construction is completed.This is because no method has been found to economically extract the stressed material.
Nowadays, it is required to pull it out and remove it after construction is completed.

This is not only to save resources and reduce costs, but also because it has become difficult to permanently occupy underground areas of public and private land.

If the length is too long, it takes a double or triple effort to excavate with earth retaining on both sides of the stressed material from the ground surface to about 3 meters underground, cut the stressed material, and then fill it back in again.

Therefore, currently, steel sheet piles are mainly used as the stress material in the mud water solidification method, and H steel piles are used as the stress material in the double organ illumination method, but the length is limited to 20 m or less and a single pile without a joint. There is.

Problems to be Solved by the Invention This invention attempts to solve the problem that a stressed material of 20 m or more cannot be easily pulled out with a low tensile force.

Measures to solve the problem: After excavating the ground and filling the hole formed with slurry solidification liquid, apply a synthetic resin film to the surface of the stressed material with a special adhesive, adhesive, or other adhesive. erecting a stress material attached or covered with a tape coated with an adhesive into the excavation hole while engaging and connecting each other's engaging portions;
'After forming an earth retaining wall around the entire circumference, and after completing the trench construction of the underground structure to at least the ground surface or after backfilling, we can save resources by pulling out the stressed material without burying more than 20 m of stressed material. This invention allows for simple and easy pulling out with low tensile force, with less noise and vibration.

Effects and Examples The present application has invented a method for pulling out even long objects of 20 m or more, which has not been tried yet, and for pulling out under sandy and gravel ground conditions.

To explain one example of its implementation, a synthetic resin film (3) is applied to the entire surface of the steel sheet pile (1) except for the engaging part (2) by applying a water-soluble adhesive or by using a tape coated with a water-soluble adhesive. Prepare by attaching or covering.

In parallel with this, an excavator drills holes (4) at regular intervals in a predetermined location in the ground, and after disposing of the remaining soil and filling the holes (4) with slurry solidification liquid, a crane is used to drill the steel sheet piles. (1) is hoisted up and erected, and several steel sheet piles (1) are attached to each other at the joints (
After the predetermined number of erections have been completed, the vertical accuracy and alignment of the steel sheet piles (1) are checked, and the hanging metal fittings are installed until the muddy water solidification wall develops its strength. Hold and secure.

After the mud solidification wall developed its strength, the holes (4) were drilled at regular intervals (5), and the mud water solidification liquid was filled in and the steel sheet piles (
1) to form a continuous retaining wall.

A synthetic resin film (
3), when the building is built, the moisture from the solidified mud permeates between the steel sheet pile (1) and the synthetic resin film (3), causing the moisture from the solidified mud and the adhesive to become fluid. Since the holding resistance is extremely reduced, the synthetic resin film can be easily removed with a tensile force of several tens of tons while leaving it in the solidified muddy material.

After that, the inside of the earth retaining wall is excavated, and once the construction or backfilling of the structure is completed, the steel sheet pile (6) is pulled out using a hydraulic jack crane.

Due to regulations such as the Road Traffic Act, steel sheet piles cannot be transported as long as 25 meters, so they are welded on-site to form a long sheet pile. When welding, we either butt-weld the stressed materials together, or weld them together. A plate is overlapped and welded to one or both sides of the area where the stressed materials are butted together.

Further, the plate may be rectangular, but if the plate is made into a vertically long rhombic plate in consideration of the pull-out resistance, the pull-out resistance can be further reduced.

The results of the on-site pull-out experiments in this application are expressed in a table as follows: After filling the excavated hole formed by excavating the ground with slurry solidification liquid as described above, a synthetic resin film is applied to the surface of the stress material using a special adhesive. , apply adhesive, or apply adhesive or tape coated with such adhesive or adhesive, and build it into the excavation hole while engaging and connecting each other's retaining parts, and install earth retaining around the entire circumference. After the wall is formed, the stressed material is pulled out after the construction of the underground structure up to at least the ground surface is completed, or after it is backfilled, so that the intended purpose can be well achieved.

[Brief explanation of drawings]

Figure 1 is a perspective view of the steel sheet pile, Figure 2 is a plan view of the ground in the excavated area, Figure 3 is a graph from the steel sheet pile pulling experiment, and Figures 4 and 5 are side views of the joint type of the steel sheet pile. , FIG. 6 is a cross section in the case of butt welding, FIG. 7 is a plan view when the plates are overlapped and welded, and FIG. 8 is a front view of the same part. Figure 1 Figure 2 Figure 7

Claims (1)

[Claims] (1) After excavating the ground and filling the mud solidification liquid into the hole formed, apply a synthetic resin film to the surface of the stress material with a special adhesive or adhesive, or apply other adhesives or adhesives. Stressed materials attached or covered with coated tape are built into the excavation hole while engaging and connecting their engaging parts to form an earth retaining wall around the entire circumference, and then the underground structure is constructed at least up to the ground surface. A method for pulling out and removing stress-retaining earth retaining materials, which is characterized by pulling out the stress-retaining materials after construction is completed or after backfilling.