JPH02171414A - Method for constructing underground continuous wall - Google Patents

Abstract

PURPOSE:To improve drilling efficiency by drilling a following provided longitudinal hole by means of a boring machine 9 along a reverse pipe inserted in an initially provided longitudinal hole and discharging mucks via the reverse pipe on the ground. CONSTITUTION:An initially provided longitudinal hole is drilled by a rotary percusion type boring machine 9. The guide holder 13 of the boring machine 9 is fitted in the guide groove of reverse pipe 2 inserted in the initially provided longitudinal hole and a rotary percusion drill 12 is fallen along the pipe 2 and simultaneously a following provided longitudinal hole is drilled. Next, slime-like mucks mixed with drilling water are pumped and discharged via the pipe 2 and a mud discharge pipe 16 and which are separated into water and mud in a setting tank 17.

Description

Detailed Description of the Invention (Industrial Field of Application) The underground continuous wall construction method of the present invention is particularly suitable for the construction of narrow I.
It is suitable for efficiently constructing an underground continuous wall, and can be used, for example, when constructing an underground water storage tank on rock that has emerged from a coral reef or other rock that has good water permeability.

(Prior Art) In the conventional underground continuous wall construction method, a large number of overlapping vertical holes are individually excavated using a boring machine to form a continuous groove.

(Problems to be Solved by the Invention) However, with the above-mentioned conventional technology, especially when constructing a narrow 1+ underground continuous wall on hard ground such as bedrock,
Because it is difficult to form a continuous groove in a consistent manner from each excavated vertical hole, it is not suitable for constructing an underground continuous wall with the desired shape and strength, and it is difficult to dispose of scraps in the form of shavings. Because it is not easy, there are problems such as reduced excavation efficiency and the inability to excavate deep vertical holes.

Therefore, the present invention aims to provide an underground continuous wall construction method that can solve the problems of these conventional techniques.

(Means for Solving the Problems) The gist of the present invention is to insert a reverse vibe with a missing circular portion into a pre-existing vertical hole that has already been excavated, and use a boring machine to drill a subsequent vertical hole adjacent to the pre-drilled vertical hole. When drilling a hole, a guide part provided on the oval part side of the reverse pipe is fitted into a guide part provided on the boring machine side, and the boring machine is slid along the reverse vibe. This is an underground continuous wall construction method in which the waste generated by the excavation is dropped through the cutout to the lower end of the reverse vibe, and discharged to the ground via the reverse vibe.

(Example) The present invention will be explained below based on the illustrated example.
The figure is an overall view showing the construction state. During construction, first, as shown in Figure 2, the first excavation hole, that is, the pre-existing vertical hole IA, is excavated using a rotary percussion type boring machine, etc. The reverse vibe 2 is inserted into the vertical hole IA. This reverse vibe 2 has a cylindrical shape with a part cut out in a semicircular shape, and a spherical side plate 4 in which a lip groove-shaped guide groove 3 is formed as a guide part is integrated into the main part. As shown in FIG. 3, the lower end side of the reverse vibe 2 is opened in a truncated shape to form an inlet 5.

Further, inside the reverse pipe 2, an air supply pipe 7 is installed along the side plate 4, which is connected to a compressor 6 installed on the ground and discharges air for air lift to the lower end side of the reverse vibe 2. A bit 8 is attached to the lower end of the side plate 4 for stirring the excavated waste in the water.

Next, a subsequent vertical hole IB is excavated adjacent to the preceding vertical hole IA using a rotary percussion type boring machine so as to overlap with the preceding vertical hole IA. This rotary percussion type boring machine 9 is equipped with a rotary percussion drill 12 that can rotate and impact at the tip of a rod 11 supported by a crawler type truck 10 on the ground, for example. A plurality of guide holders 13, which serve as guide portions that are slidably fitted in the guide groove 3 in the vertical direction, are protruded at a plurality of locations at intervals. When drilling the subsequent vertical hole IB, the guide holder 13 of the boring machine 9 is fitted into the guide '1tII3 of the reverse vibe 2 inserted into the preceding vertical hole IA, and the guide holder 13 of the boring machine 9 is drilled parallel to the reverse pipe 2. Rotary percussion drill 1 lowered by
Excavated by 2.

The excavation is carried out in the water filled in the preceding vertical hole IA and the subsequent vertical hole IB, but the insufficient groundwater level 14 is successively supplied from the ground to the vertical hole via a water supply pipe 15. Further, from the reverse vibe 2, the slime-like sludge mixed with the drilling water is pumped up and discharged via the sludge pipe 16 connected to the compressor 6, and after being separated into water and mud by the settling Ha 17, the water is discharged. The water is used again to supply water to the vertical hole via the water supply pipe 15. In this case, the said misalignment is caused by the reverse vibe 2.
The sludge passes through the arc-shaped Ota part of the shaft and is sequentially deposited at the bottom of the vertical hole IA. Riding on the rising water flow generated by the pipe 16 and the air supply pipe 7, the water rises in the reverse pipe 2 like an air lift,
The soil is sequentially removed from the mud removal pipe 16.

After completing the excavation of the subsequent vertical hole IB, the reverse vibe 2 is pulled out from the preceding vertical hole IA and the next vertical hole 1 is removed.
B, and with the subsequent vertical hole IB as a new preceding vertical hole, new subsequent vertical holes are successively drilled in the adjacent part using the boring machine 9 in the same manner as described above.

As shown in FIG. 4, for the group of vertical holes IA to IG drilled in this way, a locking fitting 18a having a T-shaped cross section is attached to the first drilled vertical hole IA from the cylindrical outer periphery. The protruding locking pipe 18 shown in FIG. 5(A) is inserted such that the locking fitting 18g protrudes toward the vertical hole IB side. In addition, the reverse vibe 2 extracted from the previously drilled vertical hole IF is inserted into the last drilled vertical hole IG, and the opposite side of the reverse vibe 2 from the guide groove 3 is shown in FIG. 5(B). As shown in , a locking metal fitting 19 having an H-shaped cross section is fitted in such a manner that it straddles the inside and outside.

The vertical holes IB to IF are provided with the locking fittings 18a.
The water stop sheet 2 is stretched between the and the locking fitting 19.
0 is installed, and concrete is poured into the water stop sheet 20 to construct the preceding element Wl. As shown in FIG. 6(A), this water-stop sheet 20 includes a water-stop member 20a made of, for example, a vinyl sheet, which is shaped like a bag with an open top and bottom and has folds that fit the inner wall surface of each vertical hole. Water stop member 2
The connecting pieces 20b and 20c each have a C-shaped cross section and are respectively provided at both ends of the locking metal fitting 18a and the locking metal fitting 19, and are inserted from above into the locking metal fitting 19 to fit and lock, respectively.

Next, the vertical hole IG on the preceding element W1 side is connected to the preceding vertical hole 2.
1A, a new subsequent vertical hole 21B is excavated using the boring machine 9 in the same manner as described above, and a group of vertical holes for the succeeding element are successively excavated in succession by repeating the same process.

For this group of vertical holes, as shown in FIG. 6(B), a water stop sheet 22 is provided with T-shaped connecting pieces 22b and 22c at both ends of a curtain-like water stop member 22a. Concrete was poured with the above-mentioned preceding elm
- An integral trailing element W2 is constructed continuously from W1. The installation of the water stop sheet 22 was carried out by JJRi ('
l! The reverse pipe 2 and the concrete 1 for the preceding element are sequentially moved to the installed vertical hole side.The connecting piece 20 is attached to the terminal end side of the preceding element Wl by removing the locking metal fitting 19 after pouring. Since a C-shaped cavity 23 surrounded by c is formed, one connection piece 22b is inserted into the cavity 23, and the other connection piece 22C is inserted into the fifth
As shown in Figure (C), this is done by inserting it into a locking metal fitting 24 with a C-shaped cross section that is fitted so as to straddle the inside and outside of the reverse vibe 2.

In this embodiment, in order to share the reverse vibe 2, the separately formed locking fittings 1, 9, and 24 are fitted and attached to the reverse vibe 2. A locking fitting having a T-shaped or C-shaped cross section may be integrally formed.

Thereafter, the following elements are successively constructed in a continuous state using the construction method described above, and their terminal ends are connected to the starting end side of the preceding element W1. Further, the cavities formed at the joints between the elements are filled with mortar or the like after cleaning and closed. As a result, an area surrounded by a continuous underground wall with high water-tightness is formed, and an underground water storage tank can be constructed within this area.

Next, another embodiment of the present invention will be described based on FIGS. 7 to 9. FIG. 7 shows a configuration in which a reverse vibe 2 is inserted into the preceding vertical hole IA in the same manner as in the embodiment described above, and then a plurality of subsequent vertical holes are simultaneously excavated using the reverse pipe 2 as a guide. The rotary percussion type boring machine 25 used here includes a plurality of parallel rods 26a, 26b, 26c and rotary percussion drills 27a, 27b that operate simultaneously.

27c are attached to each. The above-mentioned rods are mutually connected by a guide holder 28, and at the tip of the guide holder 28, although not shown, is fitted and locked into the guide groove 3 of the reverse vibe 2 as in the case of the guide holder 13 of the above embodiment. A T-shaped engagement R3 is provided, and each rod 26a, 26b, 26c has a different length.

Therefore, each rotary percussion drill 27a, 2
7b and 27c are accurately positioned so that each vertical hole can be simultaneously and efficiently excavated, and the reverse vibration 2 is used because the holes are excavated in a stepwise manner and the shavings are sequentially dropped into the pre-existing vertical hole IA side. The soil is removed through the soil in the same manner as in the previous embodiment. After the drilling is completed, the reverse vibe 2 is moved to the position of the vertical hole drilled by the rotary bar cannon drill 27c, and the boring machine 25 drills the adjacent part.

Furthermore, as shown in FIG. 8, ll'i+
Vertical hole 7 is created by continuous cutting! After the $28 is set, concrete may be placed in divided sections for each fixed span as shown in FIG. 9. In this case, locking pipes 29 and 30 each having integrally formed locking fittings, one of which is T-shaped and the other of which is C-shaped, are inserted into vertical holes spaced at predetermined intervals. Next, between each of the locking pipes 29 and 30,
Water stop sheet 3 in an embodiment in which the connection piece 22C of the water stop sheet 22 is attached to the other end of the water stop sheet 20 in the above embodiment.
1, pour concrete, and replace the preceding element W.
Build 1. Further, the trailing element W2 is constructed by pulling out each of the locking pipes 29 and 30, inserting them into the vertical holes of the next span, attaching the water stop sheet 31 in the same manner as described above, and pouring concrete.

Incidentally, the cavity formed in the connection piece portion of the water stop sheet 22 is filled with mortar or the like and closed, as in the case of the previous embodiment.

(Effects of the Invention) As is clear from the embodiments described above, in the present invention, the boring machine excavates the next vertical hole along the reverse vibe inserted into the previous vertical hole, so the continuous narrow +1
1 groove can be easily obtained and is suitable for constructing an underground continuous wall with a desired shape and strength. In addition, the excavated waste falls through the missing circular part of the reverse pipe to the lower end of the reverse pipe and is discharged to the ground via the reverse vibe, so it does not become clogged and reduce excavation efficiency.11. It is possible to easily extract pickpockets, and it is possible to excavate vertical holes at great depths.

[Brief explanation of the drawings] Figure 1 is an overall view explaining the construction state of the construction method of the present invention, Figure 2
The figure is a cross-sectional view taken along the line ■-■ in Figure 1, Figure 3 is an enlarged cross-sectional view of the part ■ in Figure 1, Figure 4 is a plan view illustrating two states in which the construction method of the present invention is applied, Figure 5 is a perspective view of a locking metal part used in the above method, Figure 6 is a perspective view of a water stop sheet used in the same method, and Figure 7 is an explanatory diagram of an excavation state according to another embodiment. FIG. 8 and FIG. 0 are explanatory diagrams of concrete placement states according to other embodiments. [Explanation of symbols] ■A to IG, 2], B... Vertical hole 2... Reverse pipe 3... Guide groove 4... Side plate 5... Inflow port 611. Compressor 7... Air supply pipe 8... Bit 9... Boring machine 10... Crawler type truck 11... Rod 12... Rotary percussion drill 13...
Guide holder 14... Groundwater level 15... Water supply pipe 16... Sludge drain pipe 17... Sedimentation h!
18...Rocking vibe 18a 19,2
4...Lock fitting 20.22...Water supply sheet 20a 22a...Water stop member 20b, 20c, 22b, 22c...Connection piece 23...
Cavity part 25... Boring machine 26a~
26C...Rod 27a-27c...Rotary percussion drill 28...Vertical hole 1 2930...Rocking pipe 31...11-Water sheet Wl...Leading element W2...Following element Fig. 1 Figure 2 Ri-eight - Snow My Life 0 Figure 3 Figure Figure 1 Method

Claims (1)

[Claims] When inserting a reverse pipe with a missing circular part into a previously excavated vertical hole and drilling a subsequent vertical hole with a boring machine adjacent to the previous vertical hole, the side of the missing circular part of the reverse pipe The guide part provided on the boring machine side is fitted into the guide part provided on the boring machine side, and the boring machine is slid along the reverse pipe to excavate, and the gap caused by the excavation is removed from the missing circle. An underground continuous wall construction method characterized in that the wall is discharged through the reverse pipe to the lower end side of the reverse pipe and discharged to the ground through the reverse pipe.