JPS58594A - Method of propulsion construction in stagnated water gravel - Google Patents

Abstract

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

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a propulsion method in a water-stagnant gravel layer, in which groundwater accumulated around a propulsion pipe is propelled while being forcibly discharged.

In the conventional propulsion method for water-retaining sand and gravel layers, a drainage hole is created in the ground near the propulsion pipe to be excavated, and the water accumulated in this drainage hole is forcibly drained from the soil to the outside using a pump, etc. Alternatively, a construction method was used to prevent groundwater from entering the face by injecting a chemical solution into the ground around the propulsion pipe to solidify the earth and sand. -However, as propulsion progressed, groundwater that had accumulated in the ground around the outer circumference of the propulsion tube flowed from the rear into the face at the tip of the propulsion tube, making excavation work difficult or causing the face to collapse, causing problems.

For this reason, chemical liquid is generally injected to stop the water, including at the face part, but it is difficult to specify the improvement range by chemical liquid injection, and even if improvements are made, a space will be created around the propulsion pipe as it is propelled. Once again, it is impossible to completely stop water flow unless water is allowed to flow in from the face.

Therefore, the present invention uses a propulsion tube with holes in the peripheral wall, alternates excavation of the face and propulsion. The purpose is to prevent the earth and sand at the face from collapsing by discharging it out of the shaft using a drainage machine such as a drain pump, and by preventing surrounding water from flowing into the face.

Next, the propulsion method in a water-retaining gravel layer according to the present invention will be explained with reference to the drawings. When performing propulsion work, a launch shaft 2 is constructed in the ground 1 at the entrance of the propulsion pipe.The propulsion pipe 4 is penetrated into the ground by a propulsion device 3 consisting of a hydraulic jack installed in the launch shaft. Although the propulsion pipe 4 at the tip thereof is not provided with a drainage hole, a drainage hole 5 may be provided in the same manner as the propulsion pipe 8 described below depending on the state of water retention in the ground.

Next, the front face portion 1a of the propulsion tube 4 is excavated, a new propulsion tube 8 is connected to the rear part of this propulsion tube 4, and the propulsion device 3 sequentially performs propulsion. Drain pipe 5a having drain holes 5 at two locations approximately at the center height position
A perforated lid 6 is screwed into the drain pipe 5a.The perforated lid 6 has an appropriate number of through holes 6a, and the through holes 6a can propel groundwater in the ground without contamination. This is a container for draining water into the pipe 4.As will be described later, once the water has been drained to the propulsion pipe 8, the blind cover 7 can be screwed into the front drain pipe 5a of the perforated cover 6. Finally, the blind lid 7 is rotated through a hole 7a provided therein. It is preferable for the sake of drainage that the two drainage tubes 5a be provided at positions slightly lower than the center of the propulsion tube, 120 degrees apart from each other with respect to the longitudinal central axis of the propulsion tube 8. The diameter of the drainage hole 5 must be sized according to the gravel in the sand and gravel layer to prevent clogging, and in the present applicant's practice, it is approximately 100 mm in diameter, and the diameter is set to be approximately 100 mm in diameter according to the propagation of the propulsion force. On the other hand, in order to eliminate concerns about strength, two drain pipes 5a were installed diagonally to the grout hole previously provided in the propulsion pipe 8.Furthermore, the front of the propulsion pipe 4 was excavated and the drain pipes 5a were installed at the rear of the propulsion pipe 8. Furthermore, the same propulsion pipe 8 is connected and pushed in continuously, and a pipe is laid in the soil. With a plurality of propulsion tubes 8 connected in series in this manner, spring water that has entered around the propulsion tubes 8 is drained into the propulsion tubes 8 through the drain hole 5 of the drainage tube 5a provided in each propulsion tube 8. 0 A drainage pump 9 is installed in the starting shaft 2, and a propulsion pipe 8
Since the water inside is sucked in and discharged to the outside, the water that has flowed into each of the front propulsion tubes 8 and the propulsion tube 4 through the through hole 6a provided in the perforated lid 6 in the drain tube 5a is not used for propulsion. It passes through the pipe 8 to the starting shaft and is discharged by the pump 9. In this state, the face portion 1a is excavated, and a new propulsion pipe 8 is inserted from the starting shaft 2 to the previous propulsion pipe 8. It is continuously pushed out again by the propulsion device 3. By repeating this process, the underground water in the ground can be discharged and promoted. A blind cover 7 is attached and closed inside the drain pipe 5a where zero drainage has been completed. Note that there is no problem with drainage even if the rear propulsion pipe is not provided with the discharge tube 5a.

As described above, in the present invention, the water around the propulsion tube can flow into the interior through the drainage hole provided on the peripheral wall, and the water can be discharged to the outside by the pump installed in the starting shaft. Water will not enter the working face and cause the working face to collapse.Drainage holes are provided in the propulsion pipe near the working face, so it is difficult for water to enter the working face, and this prevents the working face from collapsing. Improves efficiency0

[Brief explanation of the drawing]

FIG. 1 is a side sectional view showing the propulsion method of the present invention, FIG. 2 is a sectional view taken along the line ■-■ in FIG. FIG. 4 is a front view of the perforated lid attached to the drain pipe, and FIG. 5 is a front view of the blind lid.

Claims (1)

[Claims] A propulsion tube is propelled through the water-retaining gravel layer using a propulsion device, the sand that has penetrated the face is excavated and carried out backwards, and the next propulsion tube is successively propelled after the previous propulsion tube. In the propulsion construction method, which buries the pipe in the soil while excavating the pipe, groundwater stagnant outside the propulsion pipe flows into the propulsion pipe through drainage holes formed in the peripheral wall of the propulsion pipe. The groundwater level is lowered by draining the inflowing water to the outside of the pipe using a drainage pump placed inside the propulsion pipe.
A propulsion method in a water-retaining sand and gravel layer that facilitates propulsion work.