JPH07293195A - Deformation preventive construction method for natural ground - Google Patents

Abstract

PURPOSE:To easily prevent a natural ground from settling, being deformed and softened due to pressure release by arranging timberings and auxiliary structural steel members in underground cavities, and filling a void spaced from the natural ground with a filler, and thereby applying preload to the natural ground. CONSTITUTION:After a bag body 11 has been filled in a void 9 along a timbering 1, filler G is injected with pressure into the bag body 11 via an injection hose 15. In this case, the bag body 11 is of air permeability, water permeability and pressure resistance, and has its initial strength produced because of efficient dewatering as the filler is filled in, and the bag body 11 is quickly expanded. This situation thereby allows the expanded bag body 11 to be closely bonded among the timbering 1, long sized pre-receiving members 5 and a natural ground 7. Let the filler G within the bag body 11 be quickly hardened, and a filler hardened body which is identical in shape to the void 9, and is high in strength, is formed in a state that both the long sized pre-receiving member 5 and the natural ground are thereby preloaded.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for preventing deformation of natural grounds, which prevents the grounds from sinking, deforming, loosening, etc. when excavating an underground cavity such as a tunnel.

[0002]

2. Description of the Related Art As is well known, tunnel supports used in excavation of underground cavities such as tunnels are installed in the tunnel in order to hold the ground between excavation and footwork. In the erected structure to be built, one of the tunnel support works is to bend a steel material such as H-shaped steel and a steel pipe such as a steel pipe according to the shape of the tunnel, and set a certain interval in the excavating direction inside the excavated tunnel. There is a steel support work that is built in and holds sprayed concrete or the like between these steel materials to maintain the ground.

However, in such a steel support work, a gap may be formed between the support work and the ground because the surface of the excavated tunnel is not a flat surface at the time of construction. In this case,
The earth pressure of the natural ground cannot be immediately and evenly transmitted to the supporting work, and there is a possibility that the natural ground is deformed or the supporting work is deformed or twisted.

In addition, at the point where the load is locally concentrated on the legs of the support work, depending on the geology of the ground supporting the load, the ground may sink and the tunnel stability may not be maintained. Has been done.

On the other hand, a long tip receiving member, which is a steel material for the auxiliary construction method, is arranged along the periphery of the ground to be excavated in the drilling direction.
An auxiliary construction method is widely used to prevent ground subsidence by applying natural stress to this long front bearing member and supporting it with support work. In order for the member to perform a predetermined function, the long front receiving member and the supporting member must be in close contact with each other.

However, since the long front receiving member cannot be arranged on the concentric circle, a gap is generated between the long front receiving member and the supporting work, and as a result, the ground is deformed. Cannot be fully prevented.

Therefore, in order to solve these problems,
Conventionally, a method of driving a wedge between the support work and the ground and the long length receiving member to bring the support work and the ground and the long length receiving member into close contact with each other, or concrete on the legs of the support work, etc. In order to prevent the subsidence of the ground, a method of interposing a bottom plate such as a wood plate or an iron plate between the legs of the support work and the ground has been adopted.

[0008]

However, in the method in which the support work is brought into close contact with the natural ground and the long-end receiving member by driving the wedge as described above, when the void has a complicated shape. , It is difficult to prevent the initial settlement of the natural ground by filling the wedge between the supporting work and the natural ground and the long length receiving member. There was a risk that the concrete that was made would flow out.

Further, in the conventional method, since the supporting work exerts the proof stress only after receiving the subsidence of the natural ground, it is impossible to prevent the subsidence of the ground until the proof stress is generated. Also, in the method of preventing the sinking of the support legs by interposing the bottom plate between the legs of the support work and the ground, the contact area with the ground is increased and increased by interposing the bottom plate. It only reduces the stress on the ground for the area
Further, the area of the bottom plate is also limited, so that the load cannot be sufficiently dispersed.

Furthermore, since the shape and thickness of the bottom plate are constant, it is difficult to sufficiently cope with the ground condition that varies depending on the location, and it is difficult to effectively prevent the subsidence of the legs. It was

Needless to say, all of these methods require complicated construction and require a great deal of labor and time. The present invention has been devised in view of such a situation, and in the underground cavity such as a tunnel, the support work and the ground are brought into close contact with each other, and by preloading, the ground is submerged, deformed, loosened, etc. It is an object of the present invention to provide a method for preventing deformation of natural grounds that prevents

[0012]

[Means for Solving the Problems] In order to achieve such an object, a method for preventing deformation of a natural ground according to claim 1 is a steel support work and a natural ground and an auxiliary construction method built in an underground cavity such as a tunnel. The bag is loaded into the space between the steel material, and the filler is pressurized and injected into the bag to expand the space, thereby filling the space and supporting the steel support and the ground and the auxiliary method steel material. Characterized by preloading in between.

According to a second aspect of the deformation preventing method of the natural ground, the bag has air permeability, water permeability, pressure resistance and a check valve, and is made of steel by its dehydrating effect and pressure curing effect. The pressure-filled and hardened body is formed in the gap between the support work and the ground and the steel material of the auxiliary construction method.

[0014]

According to the method for preventing deformation of natural ground according to claim 1,
When the filling material is injected under pressure into the bag body loaded in the void, the bag body expands under pressure conforming to the shape of the void due to the filling material, and preloads the long-length receiving member and the ground.

According to the ground deformation preventing method of the second aspect, when the filling material is pressurized and injected into the bag body loaded in the void, the bag body is pressed by the filling material in conformity with the shape of the void. Expands. Then, the filling material is hardened quickly, and a filled hardened body having the same shape as the void is formed in a state in which the long predecessor member and the ground are preloaded, and the filled hardened body is deformed due to stress release. Prevent.

[0016]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a sectional view of a tunnel for constructing an embodiment of the inventive method according to claim 1 and claim 2, in which:
Reference numeral 1 is a steel supporter built in the tunnel 3 at a constant interval in the excavation direction, and 5 is a long tip receiving work arranged in the drilling direction of the tunnel 3 along the peripheral edge of the ground to be excavated. As in the conventional case, the steel support 1 is made by bending steel materials such as H-section steel and steel pipe according to the shape of the excavated tunnel 3. A void 9 is formed between the taper receiving member 5 and the ground 7.

In the present embodiment, first, as shown in FIG. 2, two bags 11 are respectively provided in the space 9 and the steel support 1 is provided.
Load from side to side from the vicinity of the top. The bag 11 has air permeability, water permeability, and pressure resistance, and as shown in FIG. 3, the check hose 15 is connected to the check valves 13 attached to the respective inlets thereof. It is connected to a filling material injection means (not shown). The bag body 11 may be continuous in addition to the case where the bag body 11 is divided into two as described above.

After the bag body 11 is loaded into the space 9 along the steel support 1 as described above, the filling material G is pressed into the bag body 11 through the injection hose 15 as shown in FIG. inject. Since the bag body 11 has air permeability, water permeability, and pressure resistance as described above, as the filler G is injected into the bag body 11 as described above, the filler G is efficiently dehydrated and shortened. The initial strength is generated with time, and the bag body 11 is rapidly expanded and closely intervenes between the steel support 1 and the long tip receiving member 5 and the ground 7. Then, the filling material G in the bag body 11 is rapidly hardened, and the high-strength filled and hardened body 17 having the same shape as the void 9 is preloaded on the long front receiving member 5 and the ground 7, as shown in FIG. It will be formed in the applied state.

As described above, according to the construction method of this embodiment, the bag body 11 is loaded into the space 9 between the steel support 1 and the long receiving member 5 and the ground 7, and the bag body 11 is filled with the bag body 11. By injecting the filler G under pressure by the injecting means and inflating it, the gap 9 is filled, and a preload is applied between the steel support 1 and the long tip receiving member 5 and the ground 7. By providing the strong filling and hardening body 17, the filling material G is easily filled into the space 9 between the steel supporting member 1 and the long tip receiving member 5 and the ground 7, without flowing out, and Since the bag body 11 conforms to the shape of the void 9 by the filler G and expands under pressure, after the filler G is cured, a high-strength filled and cured body 17 of the same shape as the void 9 is provided on the long-end receiving member. 5 and the ground 7 are formed in a pre-loaded state, and the filling and hardening body 17 concerned deforms the ground due to stress release. To stop.

Therefore, according to this embodiment, the load of the ground 7 can be evenly transmitted to the steel support 1 and the ground 7 can be preloaded evenly by a simple method. It has become possible to easily and reliably prevent the subsidence, deformation, and loosening of the natural ground 7 due to the release of stress due to excavation of the tunnel 3.

[0021]

As described above, according to the method of the present invention as set forth in claim 1, the gap between the steel support and the auxiliary method steel material and the ground is easily filled with the filling material, and the ground is grounded. According to the method of the present invention according to claim 2, when the filler injected under pressure into the bag is hardened, the filled hardened body having the same shape as the void is preloaded on the auxiliary steel material and the ground. Since it is formed in a state in which the load is applied, it is possible to evenly transfer the load of the ground to the steel support work and apply a preload to the ground by the invention method according to both claims, as a result, It has become possible to easily and surely prevent subsidence, deformation, and loosening of the ground due to stress relief associated with excavation of underground caverns such as tunnels.

According to the second aspect of the invention, since the bag has air permeability, water permeability, pressure resistance and a check valve, the bag is supported by its dehydrating effect and pressure curing effect. It has an advantage that a high-strength filled and hardened body can be rapidly formed in the void between the natural ground and the steel material for the auxiliary construction method.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a tunnel for constructing an embodiment of the inventive method according to claim 1 and claim 2.

FIG. 2 is a cross-sectional view of a tunnel showing a state in which a bag body is loaded in a space between a steel support and a steel material of an auxiliary construction method and a ground.

FIG. 3 is an enlarged view of part A of FIG.

FIG. 4 is a cross-sectional view of the tunnel showing a state where the filling material is injected under pressure into the bag body.

FIG. 5 is a cross-sectional view of a tunnel showing a state in which a filling and hardening body is formed in a gap between a steel support and a steel material for auxiliary construction and the ground.

[Explanation of symbols]

 1 Steel support 3 Tunnel 5 Long receiving member 7 Ground 9 Space 11 Bag 13 Check valve 15 Injection hose 17 Hardened body

Claims (2)

[Claims] 1. A bag is loaded into a space between a steel support structure built in an underground cavity such as a tunnel and a ground material and a steel material of an auxiliary construction method, and a filling material is injected under pressure into the bag. A method for preventing deformation of a natural rock, which comprises expanding the voids and applying a preload between the steel support and the natural rock and the auxiliary steel material by expanding this. 2. The bag has air permeability, water permeability, pressure resistance, and a check valve. Due to its dehydrating effect and pressure curing effect, the steel support and the ground and auxiliary steels The method for preventing deformation of natural grounds according to claim 1, wherein a filling and hardening body is formed in the voids.