JPH0518181A - Advancing method for shield machine - Google Patents

Abstract

PURPOSE:To provide the advancing method of a shield machine which can shorten the construction period, reduce the construction cost, resolve underground water pollution, and can be adaptable to large-depth construction. CONSTITUTION:The inside of an advance vertical shaft wall 1 constructed under the ground is excavated, a shield machine 6 is conveyed into the vertical shaft, and the vertical shaft wall 1 is excavated with the shield machine 6 in the advancing method under the ground. For the construction of the vertical shaft wall 1, the advance portion of the shield machine 6 of the vertical shaft wall 1 is boxed with frame materials 2 arranged on the periphery of the advance portion and frame plates 3 closing both end opened faces, and a granular material 4 is filled in the space surrounded by the frame materials 2 and the frame plates 3. A temperature adjusting pipe 23 cooling or heating the granular material 4 is removably inserted. The inside of the vertical shaft wall 1 is excavated to complete the vertical shaft while the granular material is frozen via the temperature adjusting pipe 23. For advancing the shield machine 6, the granular material 4 is melted via the temperature adjusting pipe 23, the temperature adjusting pipe 23 is removed, and the granular material 4 is excavated by the shield machine 6 for an advance under the ground.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for starting a shield machine.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 5, when a shield machine b is started from a starting shaft a constructed by a continuous underground wall construction method or a caisson construction method, the ground in front of the shaft a is ground improved c. It is a common method to reinforce by using this method to stabilize the ground in front, and then to break the vertical shaft wall of the cross-section integral required for starting to start.

[0003]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
There are the following problems. <A> It is not easy to break the shaft wall of reinforced concrete, etc., which leads to an increase in construction period and cost. <B> It costs money to dispose of waste materials such as reinforced concrete. <C> Ground improvement work on the front of the shaft is required, increasing the construction period and cost. <D> If chemical injection is used for ground improvement, it will cause groundwater pollution. <E> The starting method with ground improvement is not suitable for large-depth construction because it takes more time and cost for the deeper the depth.

[0004]

The present invention has been made to solve the above-mentioned problems, and can shorten the construction period and the construction cost, and can eliminate the groundwater pollution and have a large depth. It is an object to provide a starting method of a shield machine applicable to construction. That is, the present invention, the starting shaft wall of the shield machine is built in the ground, after excavating the inside of the shaft wall, the shield machine is carried into the shaft, and the shaft wall is excavated by the shield machine to start in the ground. In the method, when constructing the shaft wall, a starting material of the shield machine of the shaft wall, a frame material arranged on the periphery of the starting part,
A box is closed by a frame plate that closes open surfaces on both ends, and the space surrounded by the frame material and the frame plate is filled with granules, and a temperature control tube for cooling and heating the granules is removably inserted. Next, while the granules are frozen via the temperature control pipe, the interior of the shaft wall is excavated to complete the shaft, and when the shield machine is started, the granules are removed by the temperature control pipe. It is a method for starting a shield machine, which comprises melting and then removing the temperature control pipe, excavating the granular material with a shield machine, and starting the ground.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. <A> Structure of the box-out part (Figs. 2 and 3) The shaft wall is constructed by a known method such as a continuous underground wall method or a caisson method. At this time, as shown in FIG. 3, a frame member 2 having an annular shape and a frame plate 3 closing both end open surfaces thereof are attached to a rebar cage or a steel frame arranged in the body of the shaft wall 1 to form a shield machine. Unbox the starting part of. Frame material 2
Is made of a steel plate or the like, and the shape thereof is not particularly limited, such as circular or rectangular, but as shown in FIG. 3, the width is formed to be substantially equal to the width of the shaft wall 1, and the opening area is the cross-sectional outer shape of the shield machine. It should be a size that can be completely stored. On the other hand, the frame plate 3 is made of a material such as a concrete plate that can be cut by a shield machine, and a plate body having a larger opening area than the frame material 2 is used. In the space surrounded by the frame material 2 and the frame plate 3, sand, gravel,
Granules 4 such as gravel or a mixed material thereof are filled.
Fiber fibers may be mixed as a reinforcing material. In addition, as shown in FIG. 2, a required number of insertion pipes 21 and 22 that communicate with the space inside the frame member 2 in the vertical direction are joined to the upper and lower portions of the frame member 2, and inside the insertion pipes 21 and 22, respectively. The temperature control tube 23 for cooling and heating the granular body 4 is removably inserted. The temperature control pipe 23 is exposed in the space inside the frame member 2, but is protected by the insertion pipe 21 in the body of the vertical shaft wall 1. A heat insulating material (not shown) may be attached to the inner surfaces of the insertion pipes 21 and 22 in the vicinity of the frame member 2 to block heat conduction between the granular body 4 and the shaft wall 1. Also, the frame material 2
The guide pipe 24 for inserting the tremie pipe is vertically penetrated so that concrete can be placed below the box removal portion of the vertical shaft wall 1. The guide pipe 24 is made of a material that can be cut by a shield machine such as a PVC pipe in the frame member 2, and is made of a steel pipe or the like in the shaft wall 1.

<B> Excavation in the shaft wall After the shaft wall 1 is constructed, the shaft wall 1 is excavated to a predetermined depth. At this time, a cooling liquid such as brine is circulated in the temperature adjusting pipe 23 to freeze and solidify the granular body 4. As a result, the compression, shearing, and tensile strength of the granular body 4 are increased. Generally, the strength of frozen soil increases with decreasing temperature of compression, shearing, and tensile forces, and increases in the order of clay, silt, sand, and gravel at the same temperature. Therefore, it is known that when granular material 4 having a large particle size such as sand or gravel is used, a compressive strength of several hundred kg / cm2 is exhibited as in the case of concrete, and particularly 200 kg / cm2 or more is obtained for gravel. ing. Therefore, it is possible to sufficiently resist the earth pressure and water pressure on the front surface of the shaft due to the progress of excavation inside the shaft,
It does not hinder the excavation inside the vertical shaft. Further, by temporarily fixing the lower end of the temperature adjusting pipe 23 and introducing a tension force from the upper end, it can be used as a tensile member and more reliably counteract earth pressure and water pressure.

<C> Preparation for Starting the Shield Machine (FIG. 1) As shown in FIG. 1, the frame plate 3 inside the shaft wall 1 is removed, and the steel entrance 5 and the packing 51 are attached. Next, in a state where the shield machine 6 penetrates into the entrance 5, muddy water is injected into the cutter portion to balance earth pressure and water pressure in front of the shaft. Next, the freezing plant operation is stopped, hot water is circulated in the temperature control pipe 23, and the granular material 4
After melting, the temperature control tube 23 is pulled out from the insertion tube 21 and removed. Then, the granular body 4 is excavated by the shield machine 6, and the frame plate 3 arranged outside the vertical shaft wall 1 is cut to advance to the ground. As described above, after melting the granular body 4 to reduce the compression, shearing and tensile strength,
By excavating the granular body 4 with the shield machine 6, excavation can be performed easily. Further, since the outside of the shaft wall 1 of the frame material 2 is closed by the frame plate 3, it is possible to reliably prevent the intrusion of groundwater into the shaft during the excavation. Since the strength of the granular body 4 can be arbitrarily changed by adjusting the temperature, the waterproofness and earth retaining property of the starting portion of the shaft wall 1,
It is selected appropriately from the viewpoint of ease of excavation.

[0008]

Since the present invention is as described above, the following effects can be obtained. <a> During excavation inside the shaft wall, the granular material is frozen, so that the compression, shearing, and tensile strength of the granular material increase. Therefore, it is possible to sufficiently resist the earth pressure and water pressure on the front surface of the vertical shaft due to the progress of the excavation inside the vertical shaft, and the excavation inside the vertical shaft is not hindered.

<B> When starting the shield machine,
After the granules are melted to reduce the compression, shearing and tensile strength, the granules are excavated by a shield machine. Therefore, it is not necessary to break the vertical shaft wall made of reinforced concrete or the like as in the conventional case, excavation can be easily performed, the construction period can be shortened and the construction cost can be reduced, and the waste material treatment of reinforced concrete or the like is not required.

<C> By closing the outer surface side of the vertical shaft of the frame material with a frame plate that can be excavated by a shield machine,
It can prevent the infiltration of groundwater. Therefore, it is not necessary to perform ground improvement such as conventional chemical solution injection, so that the construction period and the construction cost can be shortened, and the problem of groundwater contamination can be solved.

<D> Since there is no need to improve the ground, it is possible to cope with large-depth construction in a short period of time and at low cost, and it is an effective construction method for increasing large-depth construction.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a state immediately before starting of a shield machine.

FIG. 2 is an explanatory diagram of a frame material

FIG. 3 is an explanatory view of a box-extracting structure for a shaft wall

FIG. 4 is an explanatory diagram of a state in which the shield machine penetrates the shaft wall.

FIG. 5 is an explanatory diagram of a conventional technique.

Claims (1)

Claims: 1. A starting shaft of a shield machine is constructed underground, after excavating the inside of the shaft, the shield machine is carried into the shaft and the shaft is excavated by the shield machine. In the method of launching into the ground, when constructing the shaft wall, the start part of the shield machine of the shaft wall is placed in the peripheral part of the start part and the frame plate that closes both open surfaces Then, the space surrounded by the frame material and the frame plate is filled with a granular material, and a temperature adjusting pipe for cooling and heating the granular material is removably inserted, and then, through the temperature adjusting pipe. With the granules frozen, excavate the interior of the shaft wall to complete the shaft, and when starting the shield machine, melt the granules with the temperature control tube, and then remove the temperature control tube, Excavate granular material with a shield machine and Starting method of the shield machine, which is characterized by starting inside.