JPH02266091A - Vertical shaft mechanism for shield machine starting section, its constructing method, and starting and reaching method of shield machine using its mechanism - Google Patents

Abstract

PURPOSE:To enable a shield machine to start and reach without requiring the improvement of ground by setting vertical shaft retaining core material for surrounding a vertical shaft continuously, and by erecting the core material in an underground continuous wall, to form a shield machine starting notched-section. CONSTITUTION:Vertical shaft retaining core material 2 for surrounding a vertical shaft for setting a shield machine 20, continuously is set, and is erected in an underground continuous wall 1 for starting the shield machine 20, and a notched section 12 for starting the shield machine 20 is formed. After that, on the periphery of the notched section 12, a protective internal wall for starting the shield machine 20 is constructed, and in the underground continuous wall 1 outside the vertical shaft retaining core material 2, starting retaining core material 3 with the surface processed for drawing is erected to cover the notched section 12. Besides, the reaching vertical shaft of the same mechanism is constructed, and from the underground continuous wall 1, the reaching retaining core material is drawn onto the notched section 12, and the shield machine 20 can be taken in.

Description

[Detailed Description of the Invention] <Industry> 2 Field of Application The present invention relates to a vertical shaft structure of a shield machine launch section in shield tunnel construction, a construction method thereof, and a method for launching and reaching a shield machine using the structure.

<Prior art> The shaft structure of the shield machine launch section known so far consists of constructing earth retaining walls with steel sheet piles, underground walls, etc., and boring the shield launch (arrival) section from the ground and injecting chemical liquid. By doing so, we improved the ground, excavated a shaft, installed an entrance for launching the shield machine, removed the earth retaining wall at the launch area, launched the seal machine, and reached the area where the ground had been improved. There is a ground improvement method that involves using a shield machine to remove and penetrate the retaining wall.

In addition, the earth retaining wall is constructed with steel sheet piles, underground walls, etc., and freezing pipes are installed from the ground and inside the shaft at the shield launch (arrival) part and the ground is frozen by sending refrigerant. [~There is a freezing method in which a lance is installed, the retaining wall is removed, and the shield machine is launched (reached).

Furthermore, a retaining wall is constructed using steel sheet piles, underground walls, etc., a shaft is excavated, a shield machine is brought into the shaft, a pressure plate is installed at the top of the shaft, and an entrance is installed on the retaining wall. Adding pressure equal to the earth pressure and water pressure in the starting area into the shaft,
The vertical shaft pressurized construction method is used, which involves removing the earth retaining wall and launching a shield machine.

<Problem to be solved by the invention> However, the above conventional construction methods are used depending on the ground condition of the construction area, and although each has its advantages, it is difficult to construct a shaft in a place where the construction area is narrow, such as in an urban area. This may not necessarily be sufficient if there is a limit to the amount of time available or if the construction period is limited to a short period of time.

In particular, the above ground improvement method has the following problems.

1. A period of ground improvement is required before shaft excavation.

2. Due to the excavation after ground improvement, the earth retaining wall becomes deformed, and the earth retaining wall and the soil improved ground become separated, resulting in many accidents such as water leakage during shield launch.

3゜ Ground improvement requires space and a large amount of money.

In addition, the problems with the above-mentioned freezing method include: 1. It takes a long time to install freezing pipes and freeze the ground.

2. Large ground subsidence occurs due to freezing (melting) of the ground.

3. Ground improvement requires a large amount of money.

Sometimes.

Furthermore, the problems with the pressure method include: 1. Work is under high pressure, which is unsafe.

2. A large amount of money is required for pressurized air equipment.

3. It takes a long time to set up the start-up, such as using pressurized air equipment.

etc. are possible.

In addition to the conventional method mentioned above, the double steel sheet pile method is also known, but this method uses steel sheet piles and starts excavation by pulling out the steel sheet piles when the shield machine starts, and is used to dig into soft ground or other ground. In addition to being effective under certain conditions, construction depth, and pressurized water conditions, and having a limited scope of application, all the inner walls of the shaft should be made into solid continuous walls, and the ground of the shield machine launch area should be In terms of improving the ground, it is basically the same as the ground improvement method described above, but there are still problems in that the construction period for ground improvement is prolonged and a certain degree of location restrictions are required.

This invention was made to solve the above-mentioned problems, and its first purpose is to create a stronger underground continuous wall than before without the need for ground improvement in the shield machine launch area where the ground is weak and underground water easily invades. The aim was to construct a simple earth retaining shaft for the shaft except for the starting part, and to obtain the shaft structure of the shield starting part in a short period of time within the limited planar area of the shaft.

Another object of the present invention is to provide a method for constructing a shaft that facilitates the backfilling of the shaft in some cases.

Still another object of the present invention is to provide a method for starting and reaching a shield machine by simplifying the structure of a shaft and making it easy for the seal machine to start and reach.

<Means for Solving the Problems> This invention has been made in view of the problems mentioned in 2.The gist of the invention is to provide a shaft in which a shield machine is installed, and a shaft earth retaining core that continuously surrounds the shaft. This shaft retaining core material is built into the underground continuous wall on the shield machine launch side, and a notch for shield machine launch is formed, and a protective inner wall for shield machine launch is constructed around the notch. In the shaft structure of the shield machine starting part, a starting earth retaining core material whose surface has been subjected to drawing processing is installed in the underground continuous wall outside the shaft earth retaining core material so as to cover the notch. Here, the above-mentioned shaft earth retaining core material refers to steel sheet piles, piles, reinforced concrete, etc. built into the underground continuous wall by column-type underground continuous construction method or wall-type underground continuous construction method, etc. Also, the above-mentioned starting earth retaining core material teeth,
For example, steel sheet piles and H piles can be considered.

Another gist of the invention is that a shaft structure is used on the starting side and the reaching side, and a cylindrical chamber with a sealing material is provided in each shaft along the inner periphery of the reaction wall of the shield machine and the protective inner wall for starting. A shield machine is installed to excavate the ground on the starting side of the shaft, and the starting earth retaining core material is pulled out from the underground continuous wall onto the notch of the shaft core material, and the underground continuity without core material is installed in front of the shield. Start while excavating a part of the wall, dig into the target ground, pull out the reaching earth retaining core material corresponding to the starting earth retaining core material from the underground continuous wall onto the notch of the shaft earth retaining core material, and shield it. This is a method of starting and reaching a Seal I machine, in which the machine is taken into a shaft on the reaching side where an artificial ground with a predetermined pressure is formed.

Furthermore, another invention is to erect a double core material of a shaft earth retaining core material and a starting earth retainer core material, which are punched one by one on each surface using the underground continuous wall construction method, on the shield machine launch side of the planned shaft area. The process of constructing an underground continuous wall, and driving the shaft earth retaining sheet pile as a shaft earth retaining core material that is continuous with the shaft earth retaining core material in this underground continuous wall and forming the inner surface of another shaft, and the inside of the enclosed shaft earth retaining sheet pile. The ground on the shaft starting side, which consists of the step of excavating, and the step of driving a protective inner wall around the starting shaft entrance of the shield machine of the underground continuous wall, and forming a notch in the shaft earth retaining core material that is inside the protective inner wall. The gist is the construction method for the vertical shaft structure of the shield launch section without any modification.

<Function> According to the shaft structure of the present invention, except for the starting part of the shield machine, a normal underground earth retaining core is surrounded and earth-retained, and in the starting part, the starting earth retaining core in the continuous wall is Built in one piece and sealed
At the same time, the shield face can be pressed against the underground continuous wall to support the tonosho even if the starting earth retaining core material is pulled out at the time of starting. Even when the machine excavates, it excavates at the notch in the shaft retaining core material, so it can start smoothly.

In addition, the method for starting and reaching the shaft structure is to use a shaft in which the shaft earth retaining core material and the starting earth retaining core material are built double in the underground continuous wall between the starting side and the reaching side, and the shield machine is launched. After filling the cylindrical chamber of the protective inner wall, the starting earth anchoring material is pulled out to balance the pressure of the shield face and the starting part ground,
A shield machine is used to excavate and line the planned tunnel, and the earth retaining core material on the reaching side is pulled out and taken into the vertical shaft into the artificial ground where a predetermined pressure, such as water pressure, is applied.

Furthermore, in the construction of the shaft, except for the starting part, the shaft retaining sheet piles are driven into the ground along the area of the planned shaft, and the shaft is excavated inside the sheet piles by known means such as raising the belly or cutting beams. The shaft retaining sheet pile other than the starting part and the starting retaining sheet pile are simultaneously built in an underground continuous wall to easily finish a double core material. In addition, a protective inner wall is installed around the shield machine launch portal (entrance) of the starting portion of the earth retaining sheet pile, and the earth retaining sheet pile is cut out in the inner wall to facilitate the shield's launch. In this way, in addition to the normal shaft structure, the starting side, where the ground must be strengthened, is reinforced by erecting starting earth retaining materials in the underground continuous wall, so that it does not get in the way of excavation during shield starting. It can be pulled out like this.

<Example> An embodiment of the present invention will be described below.

Figure 1 shows the main part of the shaft structure when the shield machine of this invention is launched.This will be explained according to the diagram.1 shows the column type using soil mortar on the shield launch side or the type with solidified mud water. This continuous wall is an underground continuous wall, and in this continuous wall, there are built an inner earth retaining sheet pile 2 as a shaft earth retaining core material and an outer earth retaining sheet pile 3 as a starting earth retaining core material placed at a predetermined interval from the inner earth retaining sheet pile 2. The outside of this underground continuous wall 1 is ground 4 that has not been improved, and although not shown, there are retaining sheet piles 2 on three wall surfaces other than the starting side that are connected to the inner retaining sheet piles 2 with joints, etc. , These are used to construct vertical shafts using sills and struts.

Reference numeral 5 denotes a cylindrical chamber having front and rear flanges 5a and 5b, which is provided so as to be in contact with a part of the wall surface of the shaft formed as described above, and is made of a cylindrical steel material as a whole. An inner wall 6 is cast around the outer periphery of the underground wall 1 so as to be inscribed in the underground wall 1. Note that a ring-shaped elastic first sealing material 6 and a second sealing material 7 having a predetermined width are fixed to the inside of the cylindrical chamber 5 near the center and near the rear end. Reference numeral 7 is a hinge type seal holder or the like, and the inner end thereof is inclined forward. 8 is a pressure adjustment pipe from the muddy water tank 9, and a valve 10
It is connected to the muddy water/grout supply pipe 11 through the pipe, and the water outlet end thereof opens into the inside from the top and bottom of the cylindrical chamber 5.
The front face of the shield machine 20 and the inner earth retaining sheet pile 2 are arranged so that muddy water is press-fitted between circular notches 12 for starting the shield machine. This muddy water/grau I/supply pipe 11 is connected to a grout injection pipe 14 from the middle via a valve 13, and as described later, the shield machine 2
This pipe is used as a pipe for injecting grout into the gap at the back of the segment after penetrating the underground continuous wall 1. Reference numeral 15 denotes a backfilling injection pipe, the outlet of which opens into the chamber at intervals of 90 degrees between the cylindrical chamber 2 and the skin plate 17 of the seal 1-machine 20 through valves 16. ing. 20 is a shield machine installed in such a cylindrical chamber 2, and when starting this, the tip of the cutter bit 18 is pressed and the skin plate of the shield machine 20 is pressed.]
A space 19 surrounded by the cylindrical chamber 7 and the sealing materials 6 and 7 is sealed with a backing material or the like. Furthermore, if necessary, the front surface of the shield machine 20 is filled with muddy water from the muddy water tank 9. In this case, by opening the valve 10 on the pressure regulating pipe 8 side, the water level in the muddy water tank 9 can be maintained at the set muddy water pressure to counteract the pressure of the ground. The inner earth retaining sheet pile 2 in the underground continuous wall 1 at the part facing the shielding machine 20 is cut out to a size that allows the shielding machine 20 to excavate and penetrate, forming a notch 12, and then the surface is pulled out. The inner earth retaining sheet pile 2 which has been easily waxed is pulled out upward (indicated by an arrow) and started while being excavated by a shield machine 20.

In addition, when pulling out the core material, grout material is injected into the void portion generated at the tip of the core material as necessary using an injection pipe (not shown) provided in the core material in advance. When the shielding machine 20 excavates and opens the underground continuous wall 1 and replaces the inside of the cylindrical chamber 5 with the segment for I-channel lining, it injects grout from the muddy water, grout I, and supply pipe]-1 to ensure a reliable flow. Make sure to turn off the water.

Next, the shaft structure of the shield machine starting part and its construction method until the shield machine of the present invention shown in Fig. 1 is installed in the shaft will be explained with reference to Figs. The method of starting and arriving at the shield machine will be explained step by step with reference to FIGS. 7 to 1-2.

↓Seisenbayashi construction plate First, in the planned shaft area 21, the starting side of the shield machine 20 is constructed using the type underground continuous wall construction method to construct the shaft retaining core material and starting earth, which will be described later. The underground continuous wall 22 is constructed along the temporary earth retaining construction line so that the retaining sheet piles, which are retaining core materials, can be built as double core materials at intervals of, for example, 40 marks (FIGS. 2a and 2b). During excavation, the shaft walls will be protected by muddy water.

Note that H steel can also be used as the core material.

Next, the shaft earth retaining core material 23 and the starting earth retaining core material 2/U, which have been pre-processed as described below, are placed on the continuous wall 22 filled with muddy water with double precision inside and outside. Build well. The reason for building with high precision is to prevent precision deterioration due to the impact of the earth retaining of the shaft and the sheet pile, and to protect the wax surface-treated on the starting earth retaining material 24. Mud water is naturally solidified with cement 1 because of the continuous wall-type underground construction method, but soil mortar or chemical injection may be performed instead of mud assimilation (Fig. 3 a, b).

The above-mentioned pre-processing of the core material means that the entire surface of the starting earth retaining core material 24, which is the outer sheet pile, is waxed to facilitate the pulling out described later, and the inner shaft retaining sheet pile 23 is waxed. When pulling out the sheet pile 24, the pulling resistance due to contact between the sheet piles is reduced, and the shaft retaining sheet pile 2, which will be described later, is removed from the outside.
In order to prevent water replenishment from the notch 3, a pipe spacer 25 is welded in the construction direction.

After completing the earthworks 6 and constructing the vertical continuous underground wall 22, the shaft retaining sheet pile 25, which will become the inner surface of the shaft, is driven into the shaft planned area, the retaining wall is installed, and shoring 26 is erected inside the enclosed area. The vertical shaft is constructed by excavating up to the final planned excavation surface 31. The shaft retaining sheet pile 25 and the shaft retaining core material 23 are connected by a joint or the like to prevent water intrusion (FIGS. 4a and 4b).

After completing the construction, the area around the shield starting part (planned shield starting position N) (the mine entrance) is reinforced with steel or concrete, and a protective inner wall 27 is installed. Inside this protective inner wall 27,
A cylindrical chamber 30 is set, which is provided with a first sealing member 28 and a second sealing material 29 and in which the shielding machine 20 is installed in a sealed state (FIGS. 5a and 5b).

The preparation for launch is completed by installing and installing temporary structures such as reaction walls, frames, and temporary assembly segment 1- required for shield launch into the cutting shaft at the entrance of the core material shaft. A notch 32 is provided by cutting the inside of the protective inner wall 27 of the inner retaining sheet pile 23, which is a material, to open the opening of the mine opening. In addition, the shaft earth retaining core material 2
For 3, in addition to sheet piles and H steel, reinforcing bars may also be used.

The reason why the stability of the ground is ensured even if the notch 32 is provided in the shaft earth retaining core material is that a... the starting earth retaining core material 24 is present in the underground continuous wall 22. b. A partial assimilation of the underground continuous wall 22 exists between the inner and outer core materials 23 and 24, and these are integrally connected like cardboard. C: The pipe spacer 25 prevents water from flowing inward from the starting earth anchoring material 24. In this case, it will be more effective if the assimilated body of the underground continuous wall 22 is made of a water-impermeable material.

As described above, the vertical shaft structure of the present invention is completed, but the conventional ground improvement process is omitted, only the shield starting part is reinforced, and the rest is made as simple as a general earth retaining wall. It is effective for use in urban areas because it not only shortens the construction period, but also requires the minimum floor area for constructing a vertical shaft.

Furthermore, when using a shaft as a manhole or backfilling, it is easy to restore the ground to its current state.

Shield Launch To install the shield machine, press the tip of the shield machine into the cylindrical chamber 30. Next, the valve 10 is opened to inject muddy water from the muddy water tank 9 between the front of the seals 1 to 20 and the underground continuous wall 22, and the cutter at the tip of the shield machine is exposed to the same level of ground as during excavation operation. Hold as much pressure as possible. In this way, the pressure between the shield machine 20 and the ground 4 is maintained, and the starting earth anchoring material 24 is smoothly pulled out by the wax effect. In this case, it is possible to pull out the entire core material 24, but it is more advantageous to pull out the center part to a predetermined height, which is necessary for starting the shield machine, in order to ensure that the seal 1 and the starting part are grounded (2). Figure 7a.

b).

The shield machine is moved forward at the same time as the starting earth anchoring material 24 is pulled out, but in order to stop the water in the notch 32 which is the starting well mouth, backfilling is performed after assembly into segment 1 to stop the water in the gap at the well mouth. At the same time, if necessary, the repulp 16 is opened and the first and second sealing materials 6, 7 are removed from the backfilling injection pipe 15.
Water stop grouting can also be done in between.

Preparation work for the reaching side shaft Construct a vertical shaft on the arrival side that is symmetrical to the starting side.

In addition, inside the shaft on the reaching side, there is a protective inner wall 27 that is large enough to allow the shield machine to enter the cylindrical temporary assembly segment 1.
'Cera I.'. In this temporary assembly segment 33,
Fill the earth and sand to create artificial ground 34 (Fig. 8 a, b)
).

Pressure on the artificial ground When the artificial ground 34 is constructed within the temporary assembly segment 33,
Mud water is injected from the water tank 36 using the injection pipe 35 that has been set in the temporary assembly segment 1-33 in advance, and the earth acting pressure is applied to the artificial ground when the earth retaining core material 24 is pulled out and the shielding machine 20 is introduced. 34 to provide sufficient resistance.

Note that during injection, air vent pipes 37 may be provided at several locations to facilitate injection, and these may be used to check the internal pressure (FIGS. 9a and 9b).

Reach of the shield machine and earth retaining core When the shield machine reaches the shaft while excavating the culvert, it effortlessly pulls out the earth retaining sheet pile 24 as the earth retaining core material (
] Figure O a, b). The reason why it can be pulled out easily is because of the waxing on the surface, the highly accurate erection without forced driving, and the reduction of contact resistance with the inner retaining sheet pile 23 by the pipe spacer. The stabilization of the mirror by pulling out the outer retaining sheet pile is done by adjusting the pressure of the artificial ground to balance it with the working pressure. Adjust and do this.

Introduction of the shield into the shaft The water-stopping shield machine 20 moves forward while excavating the inside of the temporarily assembled safety men 1 to 33, and introduces the whole into the shaft. Here, a water stop plate 38 temporarily placed on the rear outer periphery of the temporarily assembled segment 33 is driven into a wedge shape to seal the entire periphery of the segment. Further, on the outside of the water stop plate 38, a grout pipe provided in advance is used to inject grout into the void on the ground side to complete the water stop (FIGS. 11a and 11b).

Kari group segment 1- selection and seeding.Finally,
To remove the temporarily assembled segment 1, open the drain pipe and drain the pressure water around the segment, then pull the seal 1 machine out of the shaft, clean up the inside of the shaft, and finish the work (
Figure 12 a, b).

<Effects of the Invention> As described above, in the shaft structure of the present invention, the earth retaining core material for the shaft and the start are doubled only on the shield machine starting side, and are built into the underground continuous wall, and the other shaft side walls are built in the same way as usual. Since it is used as a shaft retaining core material, the structure is extremely simple and the construction period is short. Additionally, since there is no need to improve the ground outside the shaft, the shield launching section can be constructed in a small space. Furthermore, since not only the usual earth retaining core material around the shaft but also the underground continuous wall can be easily removed, the work to restore the land to its current state is easy.

In addition, by placing the above-mentioned shaft structure on the starting side and the reaching side = 20, the starting and reaching of the shield can be done by pulling out the earth retaining core material and forming the artificial ground on the reaching side.
The tunnel can be lined easily.

Furthermore, the construction of this shaft structure can be done with the same or less work than the normal underground continuous wall construction method, and by using the double core materials in the continuous wall according to their functions, the shield machine can be constructed. It is possible to sufficiently prevent the collapse of the ground not only before starting, but also after starting.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing the construction structure of the starting part of the shield machine according to the present invention, and Figs. They are described in order, and (a) of each figure is a plan view, (
b) is a side view. 1 (22) ... Underground continuous wall, 2 (23) ... Vertical earth retaining core material, 3 (24) ... Starting earth retaining core material, 4.
・Ground, 5...Cylindrical chamber, 1.2 (32)...
Notch, 20...Seal 1 machine.

Claims (1)

[Scope of Claims] 1) Consisting of a shaft in which the shield machine is installed and a shaft earth retaining core material that continuously surrounds this shaft, this shaft earth retainer core material is built into an underground continuous wall on the shield machine launch side. At the same time, a notch for launching the shield machine is formed, a protective inner wall for launching the shield machine is constructed around the notch, and a launching plate with a drawing process applied to the surface is provided in the underground continuous wall outside the shaft earth retaining core material. A vertical shaft structure of a shield machine starting part, in which earth anchoring material is built so as to cover the notch. 2) The shaft structure according to claim 1 is used on the starting side and the reaching side, and a cylindrical chamber with a sealing material is provided in each shaft along the inner periphery of the reaction wall of the shield machine and the protective inner wall for starting. A shield machine that excavates the ground is installed on the starting side of the shaft, and the starting earth retaining core material is pulled out from the underground continuous wall onto the notch of the shaft earth retaining core material, and the part of the underground continuous wall without core material in front of the shield is pulled out. Start while excavating the target ground, pull out the reaching earth retaining core material corresponding to the starting earth retaining core material on the reaching side from the underground continuous wall onto the notch of the shaft earth retaining core material, and apply the shield machine to the specified pressure. A method for launching and reaching a shield machine that takes in and reaches a shaft on the reaching side where artificial ground has been formed. 3) The step of constructing an underground continuous wall on the shield machine starting side of the planned shaft area by using the underground continuous wall construction method to construct a double core material consisting of a vertical shaft earth retaining core material whose surface has been drawn and a starting earth retaining core material. , a step of driving a shaft retaining sheet pile as a shaft retaining core material to become the inner surface of another shaft continuously with the shaft retaining core material in this underground continuous wall, and excavating the inside of the enclosed shaft retaining sheet pile; A step of providing a protective inner wall around the starting shaft entrance of the shield machine in the wall, and forming a notch in the shaft earth retaining core material inside the protective inner wall. Construction method of structure.