JP3566236B2 - Open shield method - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an open shield method for constructing underground structures such as water and sewage systems and underpasses in an urban area.
[0002]
[Prior art]
The open shield method is a highly rational method that takes advantage of the open-cut method (open-cut method) and the shield method. FIG. 2 schematically shows an open shield machine 1 having a front side, a rear side, and an upper side, each of which is formed by left and right side walls 1a and a bottom plate 1b connected to these side walls 1a. .
[0003]
In the open shield machine 1, the tips of the side wall plate 1a and the bottom plate 1b are formed as blades 11, and the propulsion jacks 2 are arranged vertically rearward near the center or near the rear end of the side wall plate 1a.
[0004]
Although not shown, this open shield machine 1 is installed in the start pit, the propulsion jack 2 of the open shield machine 1 is extended, and the open shield machine 1 is moved forward by taking a reaction force against the reaction wall in the start pit. Then, the first concrete box 4 forming the underground structure is suspended from above and set behind the propulsion jack 2 contracted in the tail portion 1c of the open shield machine 1. A strut is provided between the propulsion jack 2 and the reaction wall to adjust the distance as appropriate.
[0005]
In addition, the starting pit is composed of a retaining wall, and in order to start the open shield machine 1, a part of the retaining wall is cut into a mirror, but if necessary, ground improvement is performed on a front portion of the starting pit by injecting a chemical solution or the like. Sometimes I put it.
[0006]
The excavator 9 such as a backhoe excavates earth and sand from the front or upper surface of the open shield machine 1 and discharges the earth. Simultaneously with or after this earth removal step, the propulsion jack 2 is extended to advance the open shield machine 1. In the case of this advancing process, a pressing angle 8 composed of a frame using a box steel material or a mold steel is disposed in front of the concrete box 4. In the figure, reference numeral 3 denotes a partition wall which partitions the inside of the open shield machine 1 into a front face excavation section and a rear box mounting section.
[0007]
Then, the second concrete box 4 is suspended in the tail portion 1c of the open shield machine 1 before the first concrete box 4. Hereinafter, the same earth removal process, advancing process, and setting process of the concrete box 4 are appropriately repeated, and the concrete box 4 is sequentially left in the ground as the open shield machine 1 advances, and the concrete box 4 is further removed. A backfill 5 is applied to the upper surface of 4.
[0008]
When suspending the concrete box 4 in the tail section 1c of the open shield machine 1, a height adjusting member 7 such as a concrete block is disposed under the concrete box 4 and the tail box 1c is placed in the tail section 1c. The grout material 6 is filled in the left and right and lower gaps of the concrete box 4.
[0009]
In this way, when the open shield machine 1 reaches the reaching pit, it is removed and the construction is completed.
[0010]
In such an open shield method, as described above, the concrete box 4 is suspended in the tail portion of the open shield machine 1, and exits from the tail portion 1c as the open shield machine 1 advances, and remains in the ground. Things. The concrete box 4 is made of reinforced concrete, and includes a left side plate 4a, a right side plate 4b, an upper floor plate 4c, and a lower floor plate 4d as shown in FIG. .
[0011]
[Problems to be solved by the invention]
When the open shield machine 1 is advanced while excavating and excavating the face, there is a possibility that excavation and excavation and advance may not be performed smoothly due to the collapse of the ground depending on the soil quality of the ground of the face.
[0012]
SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned disadvantages of the conventional example, to provide an open shield method capable of preventing the collapse of a face during excavation of a face, excavating the soil in a stable state and advancing an open shield machine. .
[0013]
[Means for Solving the Problems]
In order to achieve the above object, the present invention arranges a propulsion jack inside the left and right side wall plates, and excavates and removes earth and sand in front of the front or upper surface opening of the open shield machine having the front, rear and upper surfaces opened. , The propulsion jack is extended, the concrete box consisting of the left and right side plates, the upper floor plate and the lower floor plate is reacted as a reaction force to advance the shield machine, and new concrete is placed behind the shrinking propulsion jack in the shield machine tail. In the open shield method of burying concrete boxes in tandem by repeating the step of suspending and setting the box from above as appropriate, in the step of excavating and discharging the soil in front, the inside of the open shield machine is The injection nozzle for the stable liquid protrudes forward from the partition wall that is divided into the face excavation part and the rear case installation part. It is an Abstract that stable injection to stabilize the cutting face portion by excavating discharge soil working face sediment.
[0014]
According to the first aspect of the present invention, the stabilizing liquid is injected into the face to stabilize the excavated earth and sand at the face, so that collapse of the ground can be prevented. Can be performed. Since the stable liquid injected into the face is blocked by the partition wall, it does not flow from the face excavation part at the tip of the open shield machine to the box installation part at the rear, which hinders the installation of concrete boxes. There is no.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a plan view showing an embodiment of the open shield method according to the present invention. The outline of the entire method is as shown in FIG. The step of setting the body 4 is repeated, and the concrete box 4 is sequentially left underground as the open shield machine 1 advances, and the upper surface of the concrete box 4 is back-filled 5.
[0016]
In the present invention, an injection plant 12 for injecting a stable liquid such as bentonite liquid into a face as shown in FIG. 1 is provided near the open shield machine 1 in the open shield machine 1 used in the open shield method in which such steps are repeated. It is installed on the ground, and a plurality of (two in the illustrated example) injection nozzles 13 provided at the injection plant 12 project forward from the partition wall 3 at the distal end of the open shield machine 1. The partition 3 divides the inside of the open shield machine 1 into a front face excavation section and a rear box installation section.
[0017]
And, in the step of excavating and discharging earth and sand in front of the above, a stabilizing liquid is injected from the injection nozzle 13 to the face 14 to stabilize the excavated earth and sand of the face 14 and improve the ground. Is excavated from the front or upper surface of the open shield machine 1 by an excavator 9 such as a backhoe to discharge the soil.
[0018]
As described above, since the earth and sand of the face 14 is stabilized by the stabilizing liquid, the ground can be excavated and discharged in a stable state without collapse of the ground, and the open shield machine 1 can be advanced.
[0019]
Then, since the stable liquid injected into the face 14 is blocked by the partition wall 3, it does not flow from the face excavation portion at the tip portion of the open shield machine 1 to the box installation portion at the rear thereof, and the concrete box 4 is installed. There is no hindrance.
[0020]
【The invention's effect】
As described above, the open shield method of the present invention prevents the collapse of the ground surface of the face when the open shield machine is moved forward while excavating and excavating the face, and in a stable state. It is capable of excavating and excavating and moving open shield machines forward.
[Brief description of the drawings]
FIG. 1 is a plan view showing an embodiment of an open shield method according to the present invention.
FIG. 2 is a vertical sectional side view showing an outline of an open shield method.
FIG. 3 is a perspective view of a concrete box.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Open shield machine 1a ... Side wall plate 1b ... Bottom plate 1c ... Tail part 2 ... Propulsion jack 3 ... Partition wall 4 ... Concrete box 4a ... Left side plate 4b ... Right side plate 4c ... Upper floor plate 4d ... Lower floor plate 5 ... Backfilling 6 ... Grout material 7 Height adjustment material 8 Push angle 9 Excavator 10 Opening
11… Cutting hole 12… Injection plant
13 ... injection nozzle 14 ... face

Claims (1)

A process in which propulsion jacks are arranged inside the left and right side wall plates to excavate and discharge earth and sand in front of the front or upper surface opening of the open shield machine with the front, rear and upper surfaces opened, A process in which the concrete box consisting of the upper and lower floors is reacted as a reaction force to advance the shield machine, and a new concrete box is suspended from above and set behind the propulsion jack shrunk in the tail of the shield machine. In the open shield method in which concrete boxes are sequentially buried in tandem by repeating the above steps as needed, in the step of excavating and discharging the front soil, the inside of the open shield machine is equipped with a front face excavation section and a rear box installation. The stable liquid injection nozzle protrudes forward from the partitioning wall, which is divided into sections, and the stable liquid is injected into the face using this injection nozzle to stabilize the face. Open shield method, characterized by drilling waste soil working face sediment Te.

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