JPS5918517B2 - Backfilling material injection device for shield construction - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention involves directly injecting backfilling material into the void created between the excavation hole and the lining segment in the shield construction method from the tail of the shield excavator.

This article concerns a backfilling material injection device for the shield construction method that can be operated rationally and efficiently.

As is well known, in tunnels constructed using the shield method, the tunnel is excavated along the outer shell of the shield machine, and a steel retaining cylinder is mainly assembled and lined inside the excavated shaft. Since the segment is assembled at the tail part of the shield machine, there is a gap between the excavated pit and the outer diameter of the earth retaining tube (hereinafter simply referred to as segment).

A gap is left that is the sum of the thickness of the shield outer shell, the inside diameter of the shield tail, and the clearance of the segment, and when the segment is assembled inside the shield machine, the gap between the center of the segment and the shield machine However, once the shield machine is propelled, the assembled segment descends into contact with the bottom of the excavated tunnel due to its own weight, and follows the center line of the target tunnel.

Therefore, the gap between the top of the assembled segment (earth retaining cylinder) and the pit is doubled to form a large gap.

Therefore, if these voids are left unattended for a long time, the slack in the ground will inevitably break, causing ground subsidence.

Unbalanced pressure will also be produced in the segment.

Therefore, in order to solve this problem and further obtain the waterproofing effect of the lining using the segments (waterproofing from spring water, etc.), it is necessary to immediately fill the voids by injecting backfilling material into the tail voids. .

Conventional backfill injection work for tail voids is performed using injection ports provided in segments, and in this case, the minimum length that can be injected after the shield machine excavates is the dimension between the grout injection ports.

That is, it is a segment/ring.

Generally, the digging speed of a shield machine is about 30 minutes to 1 hour per segment/ring, whereas in soft ground, the ground loosens in 10 to 15 minutes, causing subsidence.

Therefore, in this case, it is necessary to carry out backfilling as quickly as possible during the excavation process to prevent the ground from loosening.

However, since conventional methods rely on backfilling from the grout inlet of the segment, the backfilling operation cannot be performed unless the shield machine propels the segment/ring, and therefore a tail void situation is expected. However, it is not possible to carry out backfilling work immediately, and despite the problem of quiet subsidence caused by this, conventional methods have been resorted to.

The present invention solves this problem by adding a backfilling material injection mechanism to the tail portion of the shielding machine so that the backfilling material can be quickly injected when the shielding machine excavates and a tail void is formed. The purpose of this device is to backfill the material into the gap from the end of the shield machine.

That is, one aspect of the present invention is to provide an injection mechanism having a filling material pressure hole inside the tail part of the outer shell of a shield tunneling machine at one location on the top or at a plurality of locations distributed at appropriate positions on the top and the entire circumference. A fluid pressure cylinder that is attached to the inside of the outer shell of the machine body and has a backfilling material pressure hole bored parallel to the machine axis, with the tip of the pressure hole opening toward the rear of the machine body, and installed at the radial end of the pressure hole. A piston rod is protruded into the hole, a slider serving as a souffle bar and a stopper is attached to the end of the rod, and a backfilling material inlet is provided in front of the position where the slider is most retracted. A water discharge pipe is connected to the injection mechanism, and a pressure feed hose for backfilling material mixed through a mixing machine from a mortar pressure feed pipe and a coagulant pressure feed pipe is detachably connected to the inlet of the injection mechanism. be.

Embodiments of the apparatus of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows an outline of a general shield tunneling machine, in which 1 is the main body of the shield tunneling machine, 2 is the outer shell, and 3 is the shield tail. Parts 4 and 4 are seal rings arranged in plural numbers.

Reference numeral 10 denotes an injection mechanism, which is attached along the inner circumferential surface of the shield tail portion 3 in parallel to the fuselage axis, and is disposed at one or more locations on the top, or at multiple locations at appropriate locations around the entire circumference.

The specific structure of the injection mechanism 10 is, as shown in FIG. 2 with an intermediate plate 6 having a pressure feed hole 11 interposed therebetween, and the inner surface of the pressure feed hole 11 is a smooth circumferential surface that opens at the end of the fuselage, and the inner end is closed so that the hole axis The hydraulic cylinder 12 is fixed at the inner end by aligning the linear centers, and the piston rod 12' of the cylinder 12 is aligned with the pressure feeding hole 1.
A slider 13 is fixed to the tip of the slider 13, which has a drum-shaped edge whose outer periphery at both front and rear ends is in close contact with the pumping hole surface.

13'' acts as a souffle bar, and also acts as a plug for the pressure feeding hole 11 when it is fully advanced.

A backfilling material inlet 14 is connected to the inner plate 5 at a position in front of the most retracted position of the slider 13 of this pressure feed hole 11.
A backfilling material pressure feeding hose 1 is provided from the side, and this inlet port 14 is provided with a backfilling material pressure feeding hose 1.
5 connectors 16 are attached.

Further, a washing water outlet 17 is provided at the rear end of the pressure feed hole 11, and a drain hose 18 is connected to this.

The injection mechanism 10 is disposed at one location or in the vicinity of the top of the tail portion of the shield tunneling machine 1 (if there is a small number of locations, the outer shell 2 Attach a suitable block body along the top inner surface.

This may be provided with a mechanism having the configuration described above.

Also, by distributing a plurality of injection mechanisms,
In the case of providing the holes, they are generally distributed at appropriate positions around the entire circumference except for the bottom portion.

As a means for supplying backfilling material to the injection mechanism 10 described above, a mortar pressure feeding pipe 2 is piped through the mine from a mortar supply plant (not shown) installed outside the excavation pit, etc.
1 and a coagulant pressure feeding pipe 22 that is piped into the mine from a coagulant (for example, water glass) adjustment unit (not shown) also installed outside the mine or inside the mine as necessary, are connected to the mixer 20. , the backfilling material consisting of the mortar and setting accelerator mixed in the mixer 20 is transferred to the mixer 2.
The outlet of the mixer 20 is connected to the inlet 14 of the injection mechanism 10 through the pressure feed hose 15 connected to the outlet of the mixer 20. When connecting to multiple inlets, a branch pipe with the required number of branch ports is connected to the outlet of the mixing device 20. This branch pipe is attached, and each branch pipe is connected to each injection port with a pressure feed hose 15 from each day.

An on-off valve 23 is attached to the mixer side of each pressure feed hose 15, and a cock 25 is provided with a sample take-out tube 24 attached to the branch pipe or the outlet in the case of a single outlet.

A cock or valve 26, 27 is provided in each pressure feed pipe 21, 22 for feeding the mortar and coagulant to the mixing device 20, respectively.

The mixing device 20 is inserted from the pipe end fixed in the tunnel.
Until then, connect a suitable length of flexible pipe such as a pressure-resistant hose to make it suitable for the forward movement of the shield machine.

In addition, if the diameter of the excavated tunnel is large, or if it is necessary to operate multiple injection mechanisms at the same time to perform backfilling, multiple mixers should be used. The material may be branched so that it can be simultaneously supplied to each mixing device 5, and furthermore, it may be distributed from each mixing device to a plurality of pressure feeding hoses to measure the supply of backfilling material.

27' is a coagulant supply hand opening/closing valve.

To explain the operation of the above-mentioned washing machine according to the present invention, a foam mortar made by mixing clay sand and Portland cement with a foaming agent and water as a backfilling material and a coagulating material mainly composed of a substance such as water glass are used. These are individually adjusted and sent to the tail portion of the shield excavator 1 through the respective pressure feed pipes 21 and 22, and both are mixed through the mixer 20.

It is fed from the discharge port through the pressure feed hose 15 to the pressure feed hole 11 of the injection mechanism 10, and in this injection, first the fluid pressure cylinder 12 of the injection mechanism 10 where the injection is to be made 5 is carried out.
is actuated to move the piston rod 12' backward and move the slider 1.
3 to the most retracted position, first open the pressure feed pipe 21 valve on the mortar side and send only mortar from the pressure feed hose 15 to the pressure feed hole 11, and inject it into the tail void A formed after the shield machine excavates. First, the valves 27 and 27' from the coagulant pressure feed pipe 22 are opened, and the precipitate is mixed in the mixer 20 and injected into the void through the pressure feed hole 11.

The filling status of the backfilling material injected into the tail void A can be estimated by checking the injection pressure with a pressure gauge 28 attached to the mixer 20 and the supply amount with a flow meter 29 installed in the mortar pressure feed pipe 21. .

If the injection mechanism is equipped with multiple injection mechanisms and all of them are not used during injection operation, the injection mechanism in the unused position is the mover 1.
3 is advanced, thereby closing the tip of the pressure feeding hole 11.

In order to inject the backfilling material from one mixing device using multiple pressure feeding hoses, it is necessary to adjust the opening of the valve at hand so that the flow rate of the backfilling material in each hose does not decrease. Set it to 5 so that it flows at the flow rate.

It is important to prevent condensation within the hose.

When the filling of the void is about to end, first close the coagulant on-off valve 27' to cut off the supply and inject only one mortar in an appropriate amount, and the filling is completed (the filling supply pressure is measured by the pressure gauge). (This can be confirmed by a rise above normal levels), then all supplies are stopped.

The fluid pressure -7+J cylinder 12 of the injection mechanism 10 is plugged by protruding the piston rod and moving the mover 13 to the tip of the pressure feeding hole 11.

At this time, the mortar adhering to the circumferential surface of the feeding hole is scraped off at the front peripheral edge 13' of the moving element 13 as it moves.

Furthermore, when moving the slider 13 backward to supply backfilling material, the rear peripheral edge 13'' of the slider 13 moves back while scraping and cleaning mortar etc. adhering to the circumferential surface of the pumping hole 11. The inner diameter of the pressure feeding hole 11 is not reduced.

In the tail section of the shield machine, the cover segments (B) are assembled one after another as the shield excavator excavates, and as the shield excavator advances intermittently, the length of the tail void increases by 10 to 30 cmH. In this case, it is sufficient to carry out backfill injection as described above, and in this way, compared to the conventional injection method, the work can be performed closer to a continuous injection operation, and the setting time of the backfill material can be adjusted appropriately. This allows safe work to be carried out rationally.

When the backfilling operation is interrupted, the mover 13 is moved forward as described above to scrape off the mortar adhering to the tip of the pressure feed hole 11 to create a sealed state. Pour washing water into 11,
By attaching it to the end of the pressure feed hole 11 (and draining water through the drainage hose 18), the supply path for mortar and mixed backfilling material can be easily cleaned, and the next backfilling work can be carried out immediately.

In addition, the control mechanism shall be configured so that when the operation of this backfill injection mechanism is advanced a certain distance in accordance with the excavation progress of the shield excavator, the injection mechanism and the backfill material supply section valves etc. are automatically opened and closed. This makes it possible to automate the injection, making it more effective.

Of course, it goes without saying that the pressure fluid is supplied to the fluid pressure cylinder of the injection mechanism by receiving it from the pressure fluid supply source of the shield tunneling machine and controlling it.

[Brief explanation of the drawing]

The drawings show one embodiment of the invention. FIG. 1 is a longitudinal sectional front view, and FIG. 2 is a schematic cross-sectional view of essential parts of an injection mechanism and related backfilling material supply means. DESCRIPTION OF SYMBOLS 1... Shield tunneling machine, 2... Outer shell, 3... Shield tail part, 5... Inner plate, 6... Intermediate play), 10... Injection mechanism, 11... Force feeding hole,
12... Fluid pressure cylinder for operation, 12'... Piston rod, 13... Mover, 14... Backfilling material inlet,
15...Pressure hose, 16...Connection tool%20...
Mixing device, 21...Mortar pressure feeding pipe, 23...
Coagulant pressure feeding pipe, 23゜26.27.27'...Valve, A
... Tail void, B... Lining segment.

Claims (1)

[Scope of Claims] 1. A member with a backfilling material pressure hole drilled parallel to the machine body axis is provided at a suitable location inside the outer shell of the tail part of the shield tunneling machine, and the tip of the pressure hole is located at the rear end of the machine body. A piston rod of a fluid pressure cylinder installed with its axis opening at the diameter end of the pressure feed hole is projected into the pressure feed hole, and a moving element serving as a souffle bar and a stopper is attached to the end of the rod. , a backfilling material injection mechanism having a backfilling material inlet in front of a position where the mover is most retracted by the fluid pressure cylinder; The backfilling material inlet of the injection mechanism is equipped with a backfilling material pumping hose whose one end is connected to the discharge side of a mixing machine that receives and mixes both supplies from the mortar pumping pipe and the coagulant pumping pipe. A backfilling material injection device for shield construction, characterized in that the ends are detachably connected.