JPH03194098A - Shield method and device - Google Patents

Abstract

PURPOSE:To prevent entrance of underground water to the interior of a shield machine by mounting an annular nozzle group on the inner peripheral surface of the rear part of a tail plate end injecting a cut-off agent in a gap between placed concrete end the tail plate by means of a pressure higher than an underground water pressure. CONSTITUTION:A number of nozzles 41 are annularly on an inner peripheral surface near the rear end part of a tail plate 11 of a shield machine 1. When a front nozzle 4 is mounted where necessary, the positions of the nozzles are displaced from each other and installed in a meandering state. Concrete 13 is placed between inner forms 12 and the tail plate 11, and a cut-off agent is injected in a gap between the concrete 13 in an initial cured state and the tail plate 11 through the nozzles 41 with a high pressure. Further, the shield machine 1 is pushed by means of a jack 14, so that the nozzle 41 is moved between seal rings 6 mounted at a next step. This method and constitution prevents entrance of underground water.

Description

DETAILED DESCRIPTION OF THE INVENTION <Field of Application of Industry-E> The present invention relates to a cast-in-place lining shield construction method and a water leakage prevention device for the shield tail portion.

<Conventional technology> In general, the cast-in-place lining method involves assembling reinforcing bars inside the tail plate of a shield machine, assembling formwork inside, pouring concrete between the form and the tail plate, and then using the shield machine. This is a construction method in which the concrete is pressed and the concrete lining is finally cured.

By the way, in the cast-in-place lining construction method, when work is carried out in the ground where groundwater exists, surrounding groundwater may enter the shield machine from the opposite end of the face of the tail plate of the shield machine, causing water leakage. There is a risk that

Conventionally, a method has been adopted in which water leakage from the rear end of the tail plate as described above is prevented only by the adhesive force of the portion where the inner circumferential surface of the tail plate and the lining 7 overlap.

<Problems to be Solved by the Present Invention> When the groundwater pressure is low, water leakage could be prevented only by the adhesive force between the tail plate and the lining, as in the past.

However, when groundwater pressure is high or when a gap is created between the tail plate and the lining due to swinging of the shield machine, it is difficult to prevent water leakage only by the adhesive force between the tail plate and the lining.

If there is a lot of water leakage, the quality of the lining will deteriorate.

Therefore, the reality is that work is carried out while draining water that has entered the shield machine using a pump.

For example, when moving to the next cycle after completing one cycle using the above construction method, the reinforcing bars are assembled first, but at this time, the propulsion jacks that take the reaction force against the inner formwork are partially retracted, and the reinforcing bars are brought in. , it is necessary to secure space for assembly.

However, when the propulsion jack is partially retracted in this manner, there is a risk that the shield machine will be eccentric due to the earth water pressure received from the face, and a gap may be created between the tail plate and the lining in its initial hardened state.

Therefore, if water pressure is applied from the ground around the shield machine, water will enter through the gaps and cause water leakage.

<Objective of the present invention> The present invention was made to solve the above-mentioned problems, and provides a shield construction method and a shield tail part that can reliably prevent the intrusion of groundwater from the rear end of the tail plate. The purpose is to provide a water leakage prevention device.

<Means for solving the problems> The present invention assembles a formwork inside the tail plate of a shielding machine, pours concrete between the tail plate and the formwork, and then applies a reaction force to the formwork by jacking. In the cast-in-place lining shield construction method, in which the concrete is compressed behind the shield machine using jacks, the nozzles for injecting the water-stopping material are placed at least on the inner periphery near the rear end of the tail plate. A seal ring that is annularly provided on the surface and has water-stop properties is placed along the inner circumferential surface of the tail plate, at least near the end of the face side of the concrete placement space between the tail plate and the formwork, and During excavation, the water stop material is filled from the nozzle group into the gap between the inner circumferential surface of the tail plate and the concrete, and the rear end of the tail plate reaches near the opposite side of the face of the seal ring. This is a shield construction method.

In addition, in a shielding machine used for the cast-in-place lining construction method, a group of nozzles for injecting a water-stopping material is arranged in an annular manner on the inner peripheral surface near the rear end of the tail plate of the shielding machine, and
This water leakage prevention device for a shield tail portion is characterized in that a plurality of annular nozzle groups are provided in a direction parallel to the axis of the shield machine, and each nozzle is connected to a water stop material injection device.

<Description of the present invention> Hereinafter, the present invention will be described in detail with reference to the drawings.

<B> Structure of the entire device The shielding machine 1 shown in FIG. 1 is constructed by assembling reinforcing bars inside the tail plate 11, further assembling the inner formwork 12, and pouring concrete 13 between the inner formwork 12 and the tail plate 11. Next, the shield machine 1 is propelled by a propulsion jack 14, and at the same time, concrete 13 is pressed by a press jack 16 via a press ring 15, and finally, the concrete 13 is cured and a lining 17 is applied.

The apparatus of the present invention has a structure in which the shield machine 1 is equipped with an injection pump, an injection pipe, and a nozzle group.

<Port> Injection Pump The injection pump 2 is capable of pumping the fluid water stop material 5 at an arbitrary pressure in order to counter the groundwater pressure and the concrete 13 placement pressure.

A necessary number of the injection pumps 2 are installed in the shield machine 1, taking into consideration the size of the shield machine 1, etc.

<C> A nozzle group is arranged in an annular manner on the inner peripheral surface near the rear end of the nozzle tail plate 11, and a plurality of rows of the nozzle groups are provided in a direction parallel to the axis of the shielding machine 1.

Furthermore, it is desirable that these nozzle groups be arranged at predetermined intervals in a direction parallel to the axis of the shield machine 1 and not on the -M line.

For example, four groups of front nozzles are arranged annularly on the inner peripheral surface of the tail plate 11, and the arrangement position is shifted from the four groups of front nozzles behind the four groups of front nozzles (near the rear end of the tail plate 11). A required number of rear nozzle groups 41 are provided in a staggered manner.

At this time, the front and rear nozzles 4 and 41 are arranged so that they are not too close to each other, so that if the front nozzle 4 cannot fill the water stop material 5, the rear nozzle 41 can fill it.

Note that the nozzle may be annularly arranged only on the inner circumferential surface near the rear end of the tail plate 11.

<2> Injection tube The injection tube 3.31 is a tube body connected to the injection pump 2 at one end and connected to the front nozzle 4 and the rear nozzle 41 at the other end.

Check valves 32, 33 are provided in the vicinity of the injection pump 2 of this injection pipe 3, 31 to prevent the pumped water stop material 5 from flowing back.

<E> Nozzle valve opening mechanism Front and rear nozzles 4, Al, as shown in FIG. 4, for example,
A cylindrical body 42 with an opening in the center, and a cylindrical body 42 installed in the opening,
It consists of a valve 43 that is always biased to close by a spring or the like.

Therefore, when a pressure higher than the surrounding groundwater pressure is applied to the valve 43 from 3.31 m of the injection pipe, the valve 43 opens.

The opening pressure of the valve 43 is set by checking the groundwater pressure in advance.

Note that other valve mechanisms such as known electromagnetic valves and electric valves can be used for the front and rear nozzles 4.41.

<F> Seal ring The seal ring 6 is a ring body disposed along the inner circumferential surface of the tail plate 11.

This seal ring 6 includes at least the tail plate 11
It is disposed along the inner circumferential surface of the tail plate 11 near the face side end of the concrete casting space between the inner formwork 12 and the inner formwork 12.

Further, as shown in FIG. 3, the seal ring 6 may be installed on two or more rings.

Note that this seal ring 6 is made of a material that has water-stopping properties and water-swelling properties, and when it comes into contact with groundwater and expands,
It is in close contact with the inner circumferential surface of the tail plate 11.

<G> Water-stopping material The water-stopping material 5 used has water-stopping properties and fluidity that allows it to be pumped through the injection pipe 3.31 by the injection pump 2.

For example, waterproof grease, hydration reaction type polyurethane, etc. can be used.

<Action of the present invention> Next, the operation of the present invention will be explained.

First, as shown in FIG. 2, the seal ring 6 is placed at the predetermined position described above, the inner formwork 12 is assembled inside the tail plate 11, and the concrete 13 is placed between the tail plate 11 and the inner formwork 12. Pour concrete.

Next, the propulsion jack 14 applies a reaction force to the inner formwork 12 to propel the shield machine 1.

At the same time, press jack 1
6, it is compressed to the rear of the shield machine 1.

Then, the rear end portion of the tail plate 11 is advanced until it is located between the seal rings 6.

When the predetermined curing time has elapsed and the initial strength of the concrete 13 has been achieved, the press jack 16 is retracted to the face side, and the propulsion jack 14 is partially retracted to the face side as well, reinforcing bars etc. are installed, and the next cycle is started. Prepare.

At this time, since the propulsion jack 14 is partially retracted, the shield machine l is eccentric due to the earth water pressure received from the face, and a gap occurs between the tail plate 11 and the concrete 13 in the initial hardening state as shown in FIG. There is a possibility that a gap 18 will be formed.

Therefore, the injection pump 2 is activated and the water stop material 5 is injected into every corner of the gap 18 while maintaining a pressure higher than the groundwater pressure (Fig. 3.5).

Since this water stop material 5 maintains a pressure higher than the water pressure in the ground surrounding the shield machine 1, it can completely block off the water supply in the gap 18 into which surrounding groundwater infiltrates.

Therefore, it is possible to prevent groundwater from entering the shield machine 1 through the gap 18.

<Effects of the Present Invention> Since the present invention has been described above, the following effects can be expected.

<B> In the case of a shield machine used in the conventional cast-in-place lining construction method, when the propulsion jack is partially retracted to assemble reinforcing bars, for example, water can enter through the gap between the tail plate and the lining, causing water leakage. There was a risk.

In contrast, the shielding machine of the present invention has a structure in which the gap created between the tail plate and the lining can be filled by injecting a water stop material at a pressure higher than the groundwater pressure around the shielding machine.

Therefore, there is no risk of water entering through the gap created between the tail plate and the lining as in the conventional case, and water leakage can be reliably prevented.

<Exposure> On the inner peripheral surface of the tail plate of the shielding machine of the present invention, a plurality of annular nozzle groups are arranged in a staggered manner in a direction parallel to the axis of the shielding machine and not on the same straight line. It is a provision.

Therefore, even if a gap occurs where the front nozzle cannot inject, the rear nozzle can inject.
It is possible to prevent failure to inject the water stop material.

Therefore, leakage of underground water and the like can be more reliably prevented.

<C> In the shield construction method of the present invention, water-expandable seal rings are arranged in one row or two rows at least at the face side end of the tail plate.

Therefore, when the seal ring comes into contact with groundwater or the like and expands, the gap between the tail plate and the concrete on the face side is closed.

Therefore, when injecting the water-stopping material, the water-stopping material will not flow out into the shield machine, so the water-stopping material can be injected without waste.
Economical.

(2) The shielding machine of the present invention can reliably prevent water leakage from the tail portion, so construction can always be carried out in a dry state.

Therefore, a high quality lining can be constructed.

<E> The cast-in-place lining method can be applied even in ground with high groundwater pressure, expanding the scope of construction.

(f) Since a water-stopping material with fluidity is used, it can follow any shape change of the lining, making it possible to reliably prevent water leakage.

<G> Unlike tail seals, there is no wear and tear, so the hassle of replacement work can be saved.

<H> Since a water stop material is injected between the inner circumferential surface of the tail plate and the lining, the lining has good releasability.

[Brief explanation of drawings]

Figure 1: An explanatory diagram of one embodiment of the device of the present invention. Figure 2: An enlarged diagram of the device of the present invention. Figure 3: An enlarged diagram of the nozzle portion. Figure 4: An explanatory diagram of the state in which the water stop material is injected.

Claims (2)

[Claims] (1) After assembling the formwork inside the tail plate of the shielding machine and pouring concrete between the tail plate and the formwork, the shielding machine is propelled by a reaction force on the formwork using a jack, and at the same time, concrete is placed between the tail plate and the formwork. In the cast-in-place lining shield construction method, in which concrete is compressed behind the shield machine using a jack, a group of nozzles for injecting a water-stopping material is provided in an annular manner on the inner circumferential surface at least near the rear end of the tail plate, and also has water-stopping properties. A seal ring is arranged along the inner peripheral surface of the tail plate at least near the face side end of the concrete casting space between the tail plate and the formwork, and when the shielding machine excavates, the water stop material is applied from the nozzle group. A shield construction method characterized by filling the gap between the inner circumferential surface of the tail plate and concrete, and allowing the rear end of the tail plate to reach near the opposite side of the face of the seal ring. (2) In a shielding machine used for the cast-in-place lining method, a group of nozzles for injecting a water-stopping material is arranged in an annular manner on the inner peripheral surface near the rear end of the tail plate of the shielding machine, and this annular nozzle group is A water leak prevention device for a shield tail portion, characterized in that a plurality of rings are provided in a direction parallel to the axis of a shield machine, and each nozzle is connected to a water stop material injection device.