JP3455157B2 - Shoring construction method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention, when excavating a horizontal shaft such as a tunnel, inserts insertion pipes in parallel in a pipe roof shape on the peripheral side surface of the excavating mirror for the purpose of supporting the lining of the natural ground and stabilizing the weak portion. The reinforcement core material of the support work to prevent collapse of the mine wall, and the construction of the support work to build the lath mesh, the waterproof sheet, the support reinforcement bar, and the interior concrete formwork on the basis of this reinforcement core material. It is related to the construction method.

[0002]

2. Description of the Related Art Conventionally, various methods have been used for constructing a supporting structure by placing an insertion pipe made of a steel pipe in parallel as a reinforcing core material for a supporting structure. A hardened material layer is formed around the material and arranged in parallel.

In addition, the insertion tube is inserted into the ground by inserting it in an angular direction in which it slightly expands in the direction of excavation, and a predetermined length of the rear end of the insertion tube is overlapped with the tip of the insertion tube inserted in the previous step. By placing the reinforcing core material in the excavation direction, the reinforcement core material is used as a packing process space at the insertion port.

Further, for groundwater in the aquifer existing in the ground, a drainage pipe has been set separately, and a hardening agent is further injected deep inside the insertion pipe insertion portion. As a result, the packing process space at the insertion opening that ensures continuity in the digging direction was not provided.

In the method of forming a columnar hardening material layer around the reinforcing core material by the insertion tube, the injection material is pressure-fed into and out of the reinforcing core material through the adjoining pillar-shaped hardening material layer insertion tube. In order to prevent the air enclosed in the insertion tube and the insertion hole from being stored in the ground and ejected by injection pressure, etc., the air enclosed in the insertion tube and the insertion hole is removed and the injection material is ejected under pressure. Insertion pipes such as a jetting pipe and a packer actuating pipe that seals inflation pressure in a packer bag provided at a predetermined position are inserted into the insertion pipe.

[0006]

[Problems to be Solved by the Invention] In the conventional method of forming a hardening material layer around a reinforcing core material by an insertion tube, the boundary polymerized portion of the adjacent column hardening material layers penetrates the injection material or reaches the jet flow. There is a very uncertain factor that the area determines the extent of polymerization and it cannot be confirmed how much polymerization wrap is performed.

Further, since the reinforcing core material does not exist in the weakest overlapped lap portion and the structure of the overlapped lap portion is incomplete, there is a problem that the ground in that portion falls off.

Further, for groundwater in the aquifer existing in the ground, a drainage pipe must be separately set, and a hardening material is injected into the deep depth in front of the insertion pipe insertion portion. Since there is no such structure, when the support work is further extended from the entrance to the deeper part, the support means must be provided at the excavation start part of the extension part.

When the reinforcing core material is cast, the tip of the insertion tube inserted in the previous step and the rear end of the insert tube to be newly placed are overlapped by a predetermined length. Had to be taken one step down from the parallel insertion tube by.

For this reason, waterproofing work following the placement of the core material, H
The supporting layer made up of steel supporting bars and concrete spraying creates a step at each pouring process, causing the corrugated wall to become wavy, and the material and labor aspects of the overlapped lap extending from 3 m to 3.5 m. There was a problem that a big waste is generated from both sides.

[0011]

SUMMARY OF THE INVENTION The present invention addresses the above-mentioned problems, and adjoins a column-shaped hardening material layer having insertion tubes at both ends with the insertion tube and the intermediate position of the insertion tube as the center. By doing so, the insertion pipe to be inserted as a reinforcing core material for supporting work is positioned in the overlapped lap portion of the columnar hardened material layer to strengthen the overlapped lap portion, and the insertion pipe is drained or extended. It can also be used as a casing guide for injecting hardener into the deep interior.

Further, by constructing the predetermined length of the rear end portion of the insertion tube so that it can be cut off by crushing or the like, it is possible to cut off the insertion tube by cutting the overlapped lap portion after insertion and placement into the natural ground with a shovel or the like. The part was cut out together with the ground of the insertion part so that the pit wall level could be leveled.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. Reference numeral 1 is an insertion tube, which is provided with a plurality of open holes 11 ... on the tube wall, and the main body is made of steel pipe, etc., but the predetermined length of the rear end is a shovel made of a brittle material such as glass fiber added to PVC. It is configured as a separating portion 12 that can be crushed by the above. In addition, it is needless to say that the opening hole 11 ... Is not provided when there is no need for the construction environment such as when there is no aquifer in the ground.

Reference numeral 2 denotes a propulsion rod, which is provided with a down-the-hole hammer 22 or an appropriate excavating bit at the tip thereof and a support mechanism for detachably supporting the insertion tube 1, and is inserted by driving the lifter B of the propulsion device A. The pipe 1 is pierced and propelled by the natural ground G while supporting the pipe 1.

When the insertion of the insertion tube 1 into the natural ground G is completed,
By the lifter B of the propulsion device A, the propulsion rod 2 is detached from the insertion tube 1 and retracted and pulled out, and the inserted insertion tube 1 is inserted.
The insertion pipes are placed in parallel in a pipe roof shape along the side circumference of the excavation mirror surface at a position spaced by a predetermined distance from.
It should be noted that this insertion tube insertion means is an example, and it goes without saying that the insertion tube may be inserted into the natural ground by an appropriate means.

When the insertion pipe 1 is inserted into the natural ground G, saturated groundwater from the aquifer in the natural ground is introduced into the insertion pipe 1 through the open holes 11 ... After being discharged to the outside, the insertion portion of the insertion tube is brought into a dry state with an appropriate water content.

At the stage where the parallel placement of the insertion tubes along the side circumference of the excavation mirror surface is completed, the injection tube 3 is inserted at an intermediate position X between the insertion tube and the insertion tube, and the hardening material is pumped into the injection tube 3. By ejecting from the tip or retreating while ejecting, the columnar hardening material layer with the insertion tube at both ends and the insertion tube taken in at the middle position is formed.

In this case, the injection pipe 3 for high-pressure injection of the ground hardening material is provided with a turning means by opening an injection nozzle on the side wall of the tip, and when the hardening material is simply ejected, the tip portion is used. May be opened, or the tip may be closed and a jet hole is provided in the side wall of the tip.

The method of forming the columnar hardened material layer is selected according to the construction environment depending on the length of the interval between the insertion pipes. Further, after the columnar hardened material layer is formed by the injection pipe 3, the ground hardened material is further pumped into the insertion pipe 1 and ejected from the open holes 11 ... By constructing the layer Z, the supporting structure is further strengthened.

A column-shaped hardening material layer incorporating the insertion pipes 1a and 1b is formed at both ends by jetting or jetting of the ground hardening material, and a superposition wrap portion Y is formed at a joint portion between adjacent hardening material layers D1 and D2. The insertion tube 1 is positioned at the center of the lever as a reinforcing core material.

At the stage where the columnar hardening material layers are formed in parallel and the first shift foundation construction is completed, the injection rod is inserted into the insertion tube 1.
Further, 31 is inserted, and the injection rod 31 is propelled to the deep inside of the extension beyond the end of the insertion tube 1 to pump the ground hardening material and inject it into the deep inside of the extension to form the hardened material layer E.

The hardened material layer E supports the second shift excavation start portion of the extension portion when the support work is extended and constructed in the depth of the first shift, and special support means is provided. It is possible to start the insertion pipe parallel placement of the second shift without taking the above procedure.

At the stage where the injection by the injection rod 31 is completed, the injection rod 31 is pulled out from the insertion tube 1, but as described above, the ground hardening material is further pressure-fed into the insertion tube 1 through the open hole 11 .. If the polymerized hardened layer Z is formed at the adjacent joint portion of the columnar hardened material layer by being ejected to the surrounding soil, the supporting structure is further strengthened, and the insertion tube 1 is filled with the hardened material or the like to have strength as a reinforcing core material. Is increased. Further, the injection by the injection rod 31 is performed by an appropriate means according to the construction environment, such as jetting and jetting of the hardening material.

When the insertion pipe 1 and the columnar hardened material layer connecting the insertion pipe 1 are finished in this manner, the supported face portion is excavated and the side shaft is excavated.

At the stage where the parallel insertion tube has been excavated near the tip, the insertion port is set at a position one step lower than the parallel insertion tube in the previous step, and the insertion tube is placed in parallel and the columnar hardened material is again subjected to the same steps. While excavating the side pit while securing support by performing layer formation and deep injection, a step is created by the previous placing process, and the ground of the insertion part protruding to the mine wall is separated from the insertion pipe 1. Cut with the feasible part 12 and level.

A lath mesh is laid on a leveled pit wall, a waterproof sheet is laid, a supporting layer is constructed by supporting steel reinforcement bars and concrete spraying, and a concrete formwork is assembled to finish the interior of the pit wall. It is something to do.

Since the present invention is configured as described above, the reinforcing core member is disposed in the overlapping lap portion, which is conventionally considered to be the weakest, and the supporting structure can be made extremely strong.
It is now possible to perform drainage and support for the subsequent process start part, which had to be separately treated until now.

[0028]

[Brief description of drawings]

FIG. 1 is an overall side view showing a construction situation of an insertion driving in an object ground of an insertion pipe in an embodiment of the present invention.

[Fig. 2] Similarly, after inserting and inserting the insertion pipe into the target ground,
Overall side view showing a construction situation in which the separable part of the insertion tube is cut out and leveled

FIG. 3 is an overall front view of a horizontal shaft showing a state of a columnar hardened material layer that is connected to an insertion pipe inserted in parallel with the excavation mirror surface of the horizontal shaft.

FIG. 4 is an enlarged front view showing a state of an overlapped lap portion of a columnar hardened material layer which is continuously connected to an insertion tube inserted in parallel.

FIG. 5 is an enlarged side view of the tip of the insertion tube, showing a state in which the propulsion rod is loaded and the insertion tube is propelledly inserted into the target ground.

FIG. 6 is a side view showing a state of a distal end portion of an insertion tube and a distal end portion of an injection rod inserted into the tube, showing a state of injection into a deep portion.

[Explanation of symbols]

1 Insertion pipe 11 Open hole 12 Separation part 1a, 1b of insertion pipe Insertion pipe 2 taken into both ends of columnar hardened material layer 2 Propulsion rod 22 Down the hole hammer 3 Injection pipe 31 Deep injection rod A Propulsion device B Drifter C Horizontal shaft Excavation section D Column-shaped hardening material layers D1 and D2 Adjacent hardening material layer E Extension hardening part at deep depth G Ground X X Intermediate position between insertion tube and insertion tube Y Overlap lap portion of adjoining hardening material layer Z Adjacent hardening material Polymerized hardened layer formed at the junction of layers

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A 8-302665 (JP, A) JP-A 9-317373 (JP, A) JP-A 3-197794 (JP, A) JP-A 5- 280033 (JP, A) JP-A-11-193686 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) E21D 9/04 E02D 3/12 101

Claims (6)

(57) [Claims] 1. An insertion pipe is placed in parallel in a pipe roof shape at a predetermined interval on a side circumference of an excavation mirror surface of a horizontal shaft such as a tunnel,
By inserting the injection pipe at the intermediate position between the insertion pipe and the insertion pipe that are arranged in parallel, and retreating while pumping the ground hardening material to the injection pipe at a predetermined depth, centering the intermediate position between the insertion pipe and the insertion pipe, Construction method for supporting work, characterized in that columnar hardened material layers incorporating the insertion tube are adjacently constructed in sequence 2. A column-shaped hardening material layer is formed in a cylindrical shape by using the injection pipe as an injection rod having an injection hole formed in a side wall of a tip portion thereof and rotating and retracting while injecting a hardening material. Construction method of support work described in 1. 3. The insertion pipe is configured as a perforated pipe having a large number of open holes on its side wall surface, and groundwater in an aquifer existing in the ground is introduced into the perforated pipe to drain water. Construction method for supporting work according to claim 1 or claim 2. 4. The injection tube is used as a casing guide, the injection rod is inserted into the insertion tube, the injection rod is inserted forward of the insertion tip of the insertion tube, and the hardening material is injected deep inside the insertion tube insertion portion. Construction method for supporting work according to claim 1 or claim 2 or claim 3 5. A ground hardening material is pressure-fed into an insertion pipe having a large number of open holes formed in its side wall surface and ejected to surrounding soil through the open holes to form a polymerized hardened layer at an adjacent joint portion of columnar hardening material layers. The construction method for supporting work according to claim 3 or claim 4 6. A predetermined length of the rear end portion of the insertion pipe is configured to be cut, and the ground of the insertion portion projecting into the mine wall is cut off after completion of the construction work so that the pit wall is evenly finished. Claim 1 or Claim 2 or Claim 3 or Claim 4 or Claim 5
Construction method of the support work described