JPS609172B2 - How to build underground structures - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for constructing an underground structure, and particularly to an underground structure in which an underground continuous wall constitutes the wall of the underground structure and transmits the load of the structure to the foundation and the ground. Concerning construction methods.

Conventionally, a method has been proposed for constructing an underground structure by placing cast-in-place concrete in a trench that has been excavated while filling it with muddy water, and constructing a concrete wall to provide support to the wall. Since concrete is poured into drilling mud, there are problems with concrete strength and adhesion strength with reinforcing bars, and there is also the disadvantage that unevenness tends to occur on the wall surface, which increases the cost of repairing it.

In addition, conventionally, plate-shaped precast concrete members (P
A method of constructing an underground structure has been proposed, which involves inserting a concrete (C part village) into an excavated trench and fixing its tip to the bottom of the trench with a foot protection member such as concrete. is excavated with almost the same width as the PC board, but in reality, a gap is created around the PC board, that is, between the excavation trench wall and the PC board, and this is the cause of ground subsidence around the continuous wall made of the PC board. It becomes.

An object of the present invention is to provide a method for constructing an underground structure that eliminates the drawbacks of the conventional methods described above and is superior in construction efficiency and safety.

The method for constructing an underground structure according to the present invention includes excavating a trench underground while filling it with a stable liquid such as bentonite slurry, and inserting a plate-shaped precast into the trench having a thickness smaller than the width of the trench. While inserting the concrete member and suspending it on the ground, in order to harden the precast concrete member, concrete is placed at the bottom of the trench near the lower end of the village, that is, between the precast member and the bottom of the trench. , injecting a foot hardening material such as mortar, solidifying the stabilizing liquid between the groove wall surface and the precast concrete member, and after hardening the foot hardening material, a predetermined area above the foot hardening part of the precast concrete section. including excavating the solidified solids and soil of the stabilizing liquid on one side of the precast concrete section, i.e. on the structure construction side, to a depth; It is characterized by solving problems such as strength and disposal of waste mud water, as well as surrounding ground subsidence when a precast concrete member is simply inserted into a trench and cemented.

The features of the present invention will become clearer from the following description with reference to the illustrated embodiments.

As shown in Figure 1, first of all, a pair of L-shaped guide walls, which are set opposite to each other in advance according to the width and direction of the trench to be excavated, are used to create a groove while satisfying the stabilizing liquid blue rate. An excavator (not shown) excavates the trench to a predetermined depth including over-drilling.

Next, as shown in FIG.
The C member is held on the ground so that its tip 2 does not sit on the groove bottom part S.

For this purpose, as shown in the ``PC Parts Military Boots No. 3'' umbrella, a hanging metal fitting provided integrally with the PC member is provided, and a rectangular hole provided in the hanging fitting is also inserted. The square pipe Katsuomi (Fig. 2) is placed on the pedestal crab fin on the guide wall wing.In this way, the tPC club Murden Hitomi G-machi, the hanging fitting crabro and the square pipe Mai 81 are placed on the ground guide. The guide wall is suspended above the wall board.As mentioned above, the guide wall Kameai also defines the width and direction of the trench dormitory 4, and together with the stabilizing liquid tomb, it also serves to prevent the trench wall from collapsing. It acts to define the level of the pedestal insult for accurate positioning in the Mizo Kanto register of parts. It is closely connected to the village by the matching of the convex Toden Kaoru a and the concave Tomibari (3rd t turtle diagram).

After the installation of PC components Hyakha in Mizoden Kamenaka was completed, “P
Pour hardening concrete 3 in the bottom of the groove 6 near the tip 2 fins of member C.

Mortar can be used instead of concrete for the foot hardening of the PC member 18, but in either case, these foot hardening materials can be used, for example, as shown in Fig. Injected through 3 Eagles. Alternatively, the feed pipe can be placed on the side of the PC member, or it can be placed from the ground to the bottom of the trench independently of the PC member. The cemented concrete 38 is pumped through the pipe 32 and discharged from the hollow at the tip of the PC member to the groove bottom turtle 6.
As is clear from FIG. 5, the PC member is deposited between the tip 28 of the PC member 8 and the groove bottom i6, and the upper part thereof is filled in to create a foot protection portion 34 for the PC member.
At this time, the same volume of stabilizing liquid as the injected concrete is recovered. Next, after waiting for the stabilizing liquid 2, that is, the stabilizing liquid between the groove wall surface and the PC member, to solidify on both sides of the PC member and the hardening of the foot hardening concrete, the PC member is refilled in the groove 4. The square pipe 26, pedestal window fin, and hanging metal fitting 2 that were suspended inside are removed as shown in Figure 6. ``Even after the above-mentioned Negatari Contarito 3 Crab is cast, a solidifying agent is added to the stabilizing liquid and this is removed as necessary, so that a stable liquid with a homogeneous and predetermined strength and water quality can be obtained. In addition, when adding a caking agent to the stabilizing liquid 2 in advance, the caking time can be controlled by appropriately selecting its properties and amount. The stabilizing liquid can be solidified after pouring the foot hardening concrete 3 or when the concrete hardens.
Even if solidified solids of the stabilizing liquid are present on both sides of the PC part, the gap between the PC member and the groove wall is filled with solidified solids having a predetermined strength and water resistance. The ground will be maintained in a state that is prevented from collapsing or subsidence during trench excavation.

As shown in the second figure, even if the guide wall is removed on one side of the PC member electric light, that is, on the structure construction side, which is the right side of the PC member in the figure, the stabilizing liquid will solidify. Heavy waste and earth and sand will be excavated.

This excavation is carried out as a root cut for a PC continuous wall with a foot protection part, while providing a cut-off wall up to a desired depth of 3 points above the foot protection part 8. During this time, excavation will not be hindered by water due to the water-stopping property of the solidified material g'. Even if a pair of Mizo Maki are installed at intervals between the Kiribari Kamama, if a PC member Ryurei similar to the one described above is built in this domain, it will be installed between the opposing PC members.In this way. PC that also has Negataribe Tsurugame
After the underground continuous wall of the member frame weight is cut, structural sections 48 and 42 which are integrated with the continuous wall are constructed to complete the underground structure.

The guide plate 1 remaining on the opposite side of the PC part 8 can be removed as appropriate after the stabilizing liquid has solidified, and it can be backfilled with earth and sand if necessary. According to the present invention, since the PC members are erected without placing ready-mixed concrete in the drilling mud, the reliability of the quality and strength of the continuous wall can be increased, and there is no need to repair the wall surface.

In addition, between the continuous wall and the excavation trench wall, there is a solidified body of muddy water, which is a stable liquid, and it is substantially solid, so that it does not cover the stability of the ground from beginning to end. Due to the water-stopping effect of the solidified body of the stabilizing liquid, it is possible to improve the water-stopping performance when the built-in PC village acts as a mountain crab wall during root cutting. Furthermore, since most of the muddy water used as a stabilizing liquid for trench excavation is used as a solidified filler within the domain, large-scale equipment is not required to treat the waste muddy water, which is advantageous in terms of economy.

[Brief explanation of the drawing]

Figures 1, 2, 5, 6;
FIG. 4 is a side view and a perspective view showing an example of a PC board used for carrying out the method according to the present invention. Tortoise 2-word stabilizer ~ 12' Tristable liquid solidified body "14; Excavation groove t Tortoise groove bottom" 8: PC component "28; PC
The tip of the member, 38 three roots solidified material is also 36: Kaji Kosoko. Shocking joy Shigeki Ekanshige 3 diagrams *4 Koji key Mase Rin Atsushi face fin 7 Kaede

Claims (1)

[Claims] 1. Excavating a trench in the ground while filling it with a stabilizing liquid, inserting a plate-shaped precast concrete member having a thickness smaller than the width of the trench into the trench, and suspending the precast concrete while suspending the trench. Injecting a foot hardening material into the bottom of the groove near the lower end of the member in order to harden the member, and foot hardening after solidification of the stabilizing liquid between the groove wall and the precast concrete member on both sides of the precast concrete member. A method of constructing an underground structure comprising excavating a solid body of stabilizing liquid and soil on one side of the precast concrete member to a predetermined depth above the precast concrete member.