JPS61211423A - Refilling method of excavated trench - Google Patents

Abstract

PURPOSE:To prevent sinking of a road surface at a later date, by a method wherein a chemical solution pouring pipe is installed in a trench in which a pipe is installed, and after a subgrade replacing material is refilled up to a ground surface, vibration is exerted on the subgrade replacing material for compaction, and a chemical solution is poured. CONSTITUTION:After a pipe 5 is installed in an excavated trench 1, a chemical solution pouring pipe 11 is erected out of the ground from the bottom part of the excavated trench 1, and a peripheral sand 8 and a subgrade replacing material 9 are refilled. A mixer 12 and a grout pump 13 are connected to a chemical pouring pipe 11, and a chemical solution, such as cement, is poured through the chemical solution pouring pipe 11 as a rodform vibration compacting machine 14 is inserted into a subgrade replacing material 9 for compaction. This causes the chemical solution to enter a space under replacement of a subgrade material, which still remains even by compaction, for solidification, and prevents sinking of a road surface at a later date.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for backfilling excavated trenches in which pipes such as telephone pipes and power pipes are laid.

(Conventional technology) Conventional backfilling of excavated trenches after pipeline installation is
After laying the pipe 5 in the excavated trench 1 as shown in the figure (a)
As shown in the figure, the surrounding sand 8 is backfilled up to the top of the pipe 5, and after this surrounding sand 8 enters the excavation trench and is compacted using the ramming rod 6, the surrounding sand 8 is compacted using the rolling machine 7. , and then as shown in FIG. lOcr
Backfilling is carried out in n increments, and each backfilling layer is compacted using a rolling machine 7. When the backfilling is completed to the bottom of the backfilling 6, the backfilling 3 and struts 4 are removed, and further down to about 1trL below the ground surface. At the time and point of backfilling, pull out the sheet pile 2 using a pit puller,
Once again, compaction was carried out layer by layer to backfill to the ground surface.

(Problems to be solved by the invention) As described above, in the conventional construction method, backfilling efficiency is poor because compaction is required for each layer, and it requires a lot of time to work inside the excavated trench, making the work very dangerous. Met.

In view of these points, the present invention provides a method for backfilling an excavated trench in which backfilling of an excavated trench can be carried out without entering the trench, and the backfilling work can be carried out efficiently.

(Another means to solve the problem) Therefore, the present invention provides a pipe for injecting a chemical solution into an excavated trench in which the pipe has been installed, and after backfilling the subgrade replacement material to the ground surface, The machine applies vibration to the backfill subgrade replacement material to compact it, and injects the above-mentioned chemical solution.
The chemical solution is injected through a pipe.

(Example) FIG. 1 shows an example of the present invention, in which a pipe 5 is installed at a predetermined depth in an excavated trench 1, and then a chemical injection pipe 11 is inserted into the excavated trench as shown in FIG. 1(a). Stands up from the floor to the road surface,
Sand around the subgrade replacement material up to about 10 ports above the top pipe 5 8
backfill. After that, as shown in Figure (b), when the subgrade replacement material 9 specified by the road administrator is raised and backfilled to the bottom of the subgrade 3, the raised 3 and struts 4 are removed from outside the excavation groove. Then, the subgrade replacement material 9 is backfilled, the sheet pile 2 is pulled out at about 1 m below the road surface, and then the subgrade replacement material 9 is further backfilled up to the road surface as shown in FIG. 3(C). Next, as shown in FIG. 2D, a mixer 12 for mixing the chemical solution into the chemical injection pipe 11 and a grout pump 1 for delivering the chemical solution are installed.
3 is connected, and a rod-shaped vibratory compaction machine 14, which can compact the backfilling subgrade replacement material by vibration for about 1 to 3 m at a time, is inserted into the subgrade replacement material 9, and while compacting it, the chemical injection pipe 11 is inserted into the subgrade replacement material 9. Inject a chemical solution (cement, bentonite aqueous solution, etc.). The chemical injection pipes 11 are installed at appropriate intervals in the longitudinal direction of the excavated trench 1, and as the compaction by the rod-shaped vibrating compaction machine 14 progresses, the mixer 12 and the grout pump 1
3 to the next chemical injection pipe 11, and inject the chemical liquid from that pipe 11. Rod-shaped vibrating compaction machine 14
A sufficient penetration value can be obtained by compaction. pipe 1
The chemical solution injected from 1 enters into the subgrade replacement material,
The sand of the subgrade replacement material does not enter the lower part of the pipe 4 or between each pipe 4 and remains, and the holes left after the sheet piles are pulled out are not sufficiently filled with the subgrade replacement material and solidify. Fill in that blank. The chemical liquid injection pipe 11 is removed after the chemical liquid injection is finished.

(Effects of the Invention) As described above, according to the present invention, after backfilling the subgrade replacement material into the excavated trench to the ground surface, the subgrade replacement material is compacted by a rod-shaped vibrating compaction machine, and at the same time, from the chemical injection pipe. Because it involves injecting chemical liquid, backfilling work can be done without entering the excavated trench, and unlike conventional methods, it is possible to perform tamping work with sticks or compaction every time 20 to 50 m of subgrade replacement material is backfilled. It is possible to improve the efficiency of backfilling work as there is no need to use the subgrade replacement material, and it is also possible to use the subgrade replacement material in the spaces below the pipes and between the pipes that are not fully filled with the subgrade replacement material, and in the spaces created by pulling out the sheet piles. Even if there is a void that remains without being completely filled, the chemical solution will enter the void and solidify, so there is no risk of road surface subsidence caused by such a void at a later date, and the roadbed surrounding the pipe will be The solidification of the chemical solution that has soaked into the replacement material also provides protection against external forces on the pipe.

[Brief explanation of drawings]

FIG. 1 shows an embodiment of the present invention, and FIG. 2 shows an explanatory diagram of a conventional excavated trench backfilling method. 1... Excavation groove, 5... Pipe, 8.9... Subgrade replacement material, 11... Pipe for chemical injection, 14... Rod-shaped vibration compaction machine Year 1 Figure (0-) ( Su (6)
” Chiku 2 Zu (Ku) (I2 (,1)

Claims (1)

[Claims] A chemical injection pipe is installed in the excavated trench where the pipe has been laid, and after backfilling the subgrade replacement material to the ground surface, a rod-shaped vibration compaction machine applies vibration to the backfilled subgrade replacement material to compact it. A method for backfilling an excavated trench, characterized in that, in addition to compacting, a chemical solution is injected from the chemical solution injection pipe.