JPH037799B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention, after the primary lining in shield excavation work, easily stops water leakage from the joints of the lining ring, the back of the injection port, etc., and facilitates the secondary lining. This paper relates to a method to stop leakage from the primary lining surface of tunnels using the shield method.

As is well known, in the method of excavating a tunnel underground, in order to complete the intended passage by covering the excavated cavity wall, ring segments for lining are sequentially assembled and the excavated ground is fixed. When the lining segments are sequentially assembled and connected in a ring, cement mortar, etc. is injected back into the space between the back side and the ground and allowed to solidify, filling the space and preventing groundwater from entering the tunnel. However, because a large number of segments are connected and lined inside the underground mine every few minutes, it is practically difficult to completely stop water with backfilling material. When we consider the causes, we find that there are various causes, such as insufficient filling during backfilling.In this case, too, there are various phenomena, but it is difficult to confirm the actual cause, and among them, Backfilling material B does not go around the bottom of the lining ring that is later pushed out from the machine tail, and since segment 1 and ground mass A are in contact, groundwater flows inward from the segment joint through the contact area with the ground mass. or backfill material B is excessively injected into the ground A through the voids in the ground A, and backfilling is performed unevenly around the lining ring, causing the backfill material to leak into the ground A. B does not provide a water-stopping effect (see Figure 6). Or, the sealing gasket attached to each segment is damaged during segment assembly, combined with uneven injection of backfill material, or high water pressure in the ground (great underground depth). Water leaks from an incompletely sealed area where backfilling is not sufficient. Furthermore, when the backfilling layer is broken due to fluctuations in the reaction force acting on the lining ring when the shielding machine is propelled, a breakage phenomenon occurs between the backfilling part and the ring, or when the shielding machine Water leakage due to destruction of the backfill injection part, such as when cracks occur in the backfill layer due to knocking phenomenon during propulsion. Furthermore, the segments cannot be assembled in a perfect circle during lining, but are assembled in a slightly loose circle, which causes the joints of the segments to expand, reducing the sealing effect and causing water to leak from this area. Furthermore, when the shield machine is propelled, the jacking does not act evenly on the rear segments, causing distortion in the joints of the lining ring and causing water leakage. Another problem is that it can occur.

Therefore, as a countermeasure against such water leakage, the joints of the segments are caulked from the inner surface of the lining using a caulking material to stop water. To do this, clean the inside of the tunnel after the backfilling work, retighten the segment connection bolts, and check for water leaks at the joints. However, when performing this caulking work, the leaking area must be covered from the front side inside the tunnel, so the leakage will successively move to adjacent areas.
As a result, there are drawbacks such as the need to caulk the entire circumference of the joint. Furthermore, if the caulking work is not done before water leakage becomes severe, it will be difficult to prevent water leakage, resulting in poor work efficiency and increased construction costs.

The present invention solves such problems, improves workability, and quickly responds to water leaks, making it possible to easily and reliably prevent water leaks, and to prevent water leaks that occur during lining after excavation using the shield method. To provide a water stop construction method for a lining part that can prevent water damage to a minimum extent.

In the present invention, as a segment of the primary lining ring in the shield construction method, at least two gasket attachment portions are provided at appropriate intervals at the joint portion, and a water stop agent filling groove is provided between the gasket attachment portions. , and is equipped with a water-stopping agent injection part from inside the tunnel for the water-stopping agent filling groove, and is further equipped with a cap having a mechanism for injecting the water-stopping agent into the grout injection port, and performs primary lining. In order to deal with water leaks later, in case of water leakage at the segment joint, inject and fill the water stop agent into the filling groove from the water stop agent extraction part near the relevant position, and for water leakage at the grout injection port, fill it with a stopper installed in the cap. The purpose is to pressurize the water stop agent into the interior from the water agent injection part and inject the water stop agent directly into the water leakage part to stop water at the segment part.

Below, the present invention will be described in detail with reference to the drawings. First, what is shown in FIG. 1 is a specific example of a steel plate lining segment 10 for implementing the construction method of the present invention. On each outer surface 11', 12' of the flange 11 in the long side direction and the flange 12 in the short side direction, which form the joint part, a second
As shown in the figure, between the segment top plate 13 and the flange end face 14, a gasket fitting groove 15, a water stop agent filling groove 16, a gasket fitting groove 15', and a fastening bolt hole 17 are formed in order from the top plate 13 side. The grooves 15, 16, 15' are cut on the two surfaces at required intervals, and the water-stopping agent filling groove 16 in particular is designed to communicate with each other. A sealing gasket 18 is installed in advance in the gasket fitting grooves 15, 15', or is installed during assembly. In addition, for the water stop agent filling groove 16, a liquid injection stopper 20 was attached via a connecting pipe 21 at one or more appropriate locations on the side opposite to the joint surface, that is, on the inside of the flange 11 (or 12). A temporary sealing thin film piece 23 is attached to the end of the connection hole 22 communicating with the liquid injection tap 20 to prevent foreign matter from entering. In addition, a water-stop cap 25 as shown in FIG. has a water stop agent injection port 2 with a built-in check valve.
7 is attached to the inside of the cap 25, a flexible foreign matter intrusion prevention material 2, such as a sponge, is attached to the inside of the cap 25 to prevent foreign matter from entering the inside of the cap.
8 is filled in an appropriate amount, and a protective cover 29 is attached to the outside of the injection port metal 27.

Such ring cement 10 for lining is sequentially fed to the assembly excavation section by the tail section of the shield machine as in the conventional method, with the side adjacent to the gasket mounting surface being flat, and then the backfilling material is The primary lining is carried out by grouting, and during this primary lining, after each segment is fastened and the backfilling work is completed, groundwater is collected at the joints and the locations where grout is used, depending on the condition of the excavated ground. If you find a leaking part, for example, a joint between segments 10, apply a water stopper (for example, urethane-based drug, etc.) to the nearest liquid injection tap 20 using a small injection device or a power pump. (not shown), the joint part of the segment 10 will be placed on the ground side A, as shown in Fig. 4.
Backfilling material B is injected into the void,
This layer is sealed by the outer gasket 18, and the inside of the tunnel is sealed by the inner gasket 18, so a water stop agent can be filled between the two seals (gaskets 18 and 18). The entire circumference of the space formed by the groove 16 is filled with the water stop agent C, and by filling not only the groove but also the space between the gaskets 18, 18 before and after the groove, it is able to prevent water leakage that has flowed into the joint. The water sealing agent reacts and condenses at the contact area, sealing the area and preventing water from entering other areas. In addition, if an external force acts on this locally water-stopped area and even a small amount of water leaks to the adjacent area, the unreacted water-stopping agent will react and quickly stop the water. Water leakage can be easily prevented. In addition, the sealing function when screwing in the cap at the grout injection port 19 after backfilling work was insufficient, or even when the cap was not in use, the sealing process was insufficient when attaching the cap to the grout injection port. (Generally, when screwing the cap into the inlet,
The threaded part is threaded with sealing tape wrapped around it, but when doing so, the sealing tape is not wrapped evenly around the threaded part, and the tape breaks off or shifts partially, causing the seal to fail. When water leaks occur in areas where water may become uneven, water leakage often occurs due to the high water pressure underground (often excavated deep underground, especially at the bottom of rivers or the bottom of the seabed). It is extremely dangerous to remove the cap, repair the seal, and reinstall it (because the depth of the tunnel being excavated is naturally large, and the associated water pressure is also high). However, if the cap is removed, high-pressure water may gush out into the tunnel, making it difficult to reinstall the cap). In such a case, attaching a water-stopping agent injection device to the water-stopping agent injection port 27 provided on the water-stopping cap 25 and press-fitting the water-stopping agent into the grout injection port 19 will prevent foreign matter from entering inside. The prevention material 28 is pushed away to the ground side, and the water stop agent flows into the grout inlet 19 of the segment 10, so that coagulation progresses due to the reaction between the pressurized water accumulated in the area and the water stop agent. Naturally, the water-stopping agent also permeates along the threaded portion of the cap 25 and reacts with the intruding water to condense, resulting in a water-stopping action, and water leakage is quickly prevented.

In addition, in the ring segment for lining described above, it is also possible to adopt a structure in which the water stop agent filling groove 16 is carved all around the outer surface of the entire flange, for example, by adopting a key segment etc. ). In this case, work efficiency will be improved by increasing the number of liquid injection taps.

In this way, as a measure to prevent water leakage after lining, a water stopper injection port is installed in advance at each segment joint or grout injection port where water leakage is predicted to occur. By press-injecting a water sealing agent prepared in advance from inside the tunnel at the specified location, even if the cause of the leak is unknown, unlike passive measures such as conventional caulking to prevent water leaks, the chemical agent can be applied to the main parts of the tunnel. Through injection, it is possible to achieve the purpose without requiring excessive injection, and it is possible to economically and reliably prevent water leakage in a short time, making subsequent work easier. This is how it could be done.

In accordance with the spirit of the present invention, even if a concrete segment is used as a lining ring, the water stop agent filling groove 16a should be filled with the sealing gasket groove 1 in advance at the joint, as shown in FIG.
5a and 15a, and this water stop agent filling groove 16a
The grout injection hole is equipped with a water stop agent injection hole 22' and a water stop agent injection port 20' (with a built-in check valve mechanism) from the inside position during lining, and the grout injection port is equipped with the above-mentioned specific example. By using a cap equipped with a similar cap, the desired water-stopping treatment can be carried out. Further, the water stop cap is not limited to the above embodiment.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a specific example of a steel lining ring segment used to carry out the method of the present invention, FIG. 2 is a cross-sectional view of the connecting flange of the ring segment shown in FIG. 1, and FIG. Detailed sectional view of the grout inlet with a water stop cap attached, Figure 4 is a diagram showing the operating mode when water is stopped, Figure 5 is a diagram showing the connection end in the case of a concrete segment, Figure 6 is a diagram showing the shield It is a figure showing one aspect of backfilling material injection of an excavation tunnel by a construction method. 10... Ring segment for lining, 11, 12
...Flange, 13...Segment top plate, 15,
15', 15a, 16a... Gasket fitting groove,
16...waterstop agent filling groove, 17...bolt hole for fastening, 18...gasket, 19...grout inlet, 20...liquid injection plug, 20', 27...inlet fitting,
21... Connection pipe, 22... Connection hole, 25... Water stop cap.

Claims (1)

[Scope of Claims] 1. As a segment of the primary lining ring in the shield construction method, at least two gasket attachment portions are provided at appropriate intervals at the joint portion, and a water stop agent filling groove is provided between the gasket attachment portions. In addition, the water-stopping agent filling groove is equipped with a water-stopping agent injection port from inside the tunnel, and the grout injection port is equipped with a cap that allows the water-stopping agent to be injected, thereby preventing water leakage after the primary lining. For water leakage at segment joints, inject and fill the filling groove with a waterstop agent from the waterstop agent injection port near the location, and for water leakage at the grout injection port,
The primary lining part in the shield construction method, which is characterized by injecting a water-stopping agent into the interior from a water-stopping agent injection part provided in the cap, and injecting the water-stopping agent directly into the leakage area to stop water at the segment part. How to stop water.