JPS5830973B2 - Sewer pipe leakage treatment method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a water leakage treatment method that permanently prevents water leakage from not only new sewer pipes but also existing sewer pipes.

Sewer pipes that are buried underground usually leak due to factors such as the flow of groundwater, natural phenomena such as earthquakes and ground movements, as well as aging of the pipe itself or its joints. In addition, effective preventive measures were required as these could cause secondary accidents that would affect various areas, such as changes in treatment facilities, road surface depressions, and uneven settlement of pipes.

In view of these circumstances, the present invention provides a ring-shaped grout backing from the inner surface of cracks in pipes or segments, or water leakage points in joints, which forcibly drains water leakage in the water retention layer. We would like to provide a new water leakage prevention method that simultaneously maintains the area around the pipe in a reduced pressure state and then injects a long gel time chemical from the outside to simultaneously improve the ground around the leakage point and waterproof it. That is.

Hereinafter, the construction method of the present invention will be described in more detail with reference to one embodiment. 1 is a sewer pipe buried underground, 2 is a grout backing with a concave cross section, and the inner groove 2' is the inner surface of the sewer pipe 1. Install the jack 3 so as to include the water leakage point 1'.
etc., and 4 is the one fixed in a ring shape with the above-mentioned sewer pipe 1.
This is a grout pipe that is drilled from the ground outside the ground.

As illustrated in FIG. 1, the jack 3 has a plurality of stretchable grouts 3b arranged radially from its central portion 3a, and the grout backing is attached to the tips of the jacks 3b via branch rods 3c. This supports the second presser plate 3d.

Furthermore, 5 is a drain pipe provided on an extension of the optional upper base 3b of the jack, and whose hollow hole 5' passes through the press plate 3d and opens into the inner groove 2' of the grout backing. The other end of the hole 5' communicates with a vacuum pump (not shown) via a drain hose 6.

The construction method of the present invention is to install the previously described equipment into the existing sewage pipe 1.
After installation inside and outside of the sewer pipe, the vacuum pump is operated and the drain hose 6 forcibly sucks and discharges the accumulated water on the peripheral wall of the sewer pipe through the inner groove 2' of the grout backing 2. is in a reduced pressure state.

When the discharge of the accumulated water from the drain hose 6 is completed in this way, a certain amount of water is injected into the outer circumference of the sewer pipe 1 via the grout pipe 4, and the drain hose 6
Measure the amount of water discharged from the tank to check the suction status of the injected water.

Next, a suitable long gel time chemical solution is injected from the grout pipe 4, and after confirming that the chemical solution sucked by the drain hose 6 has reached a predetermined concentration as described above, the vacuum pump is stopped. discontinue supply,
The construction work is completed by waiting for the chemical solution filled around the outside of the sewage pipe 1 and the leakage point to harden, and then removing internal devices such as jacks.

As described above, the accumulated water in the water layer is sucked by the drain hose 6,
We have described a construction method in which a chemical solution is injected from the grout pipe 4 while discharging the water, but in the complete opposite case, the grout pipe 4 is connected to a vacuum pump to suction and drain the accumulated water (in this case, Even if the chemical solution is injected through the drain hose 6 (in this case, referred to as a grouting hose), the same grouting effect can be obtained.

In general, cement-based or water glass-based (instant setting type) injection chemicals can be used, but the gel time can be adjusted to a certain extent because it is necessary to prevent the breathing phenomenon associated with ground improvement as much as possible. something is required.

In addition, when calculating the amount of drug solution to be injected, the following equation may be used.

Q-γ■±α= nXα×V ±α However, Q; Amount of chemical solution injected n; Porosity α; Gap filling rate ■; Target amount α; Excess/deficiency amount of injected chemical solution (α × 0.5 nα ■ On the other hand, The drilling position of the grout pipe with respect to the sewer pipe is determined by the radius of arrival of the grout, which can be calculated using the following equation.

n; soil porosity ; Soil hydraulic conductivity β; Viscosity of grout h; Hydraulic head pressure of injection grout γ.

; Injection hole radius t; Injection time (gel time) For example, if the hydraulic conductivity (K) of soil is I x 10-'cI
rL/sec, porosity of soil particles (n) For a ground of 50%, the viscosity of the grout (b) is 6 cps, the head pressure of the injection grout (h) is 4 kg/ml, and the injection radius (γ).

) is 2.5 CrrL and the injection time (gel time) (t) is 600 seconds to find the radius of arrival of the grout.If you apply these numbers to the above calculation formula, it will be -, and in this case, water dilution etc. should be taken into consideration. This shows that it is only necessary to drill the grout pipe at a position approximately 177Z away from the outer periphery of the sewer pipe.

The construction method of the present invention described above improves the ground in the area by suction and injecting a chemical solution to replace the accumulated water around the sewer pipe, and at the same time, the chemical solution is applied to the cracks that cause water leakage in the sewer pipe. Since it is a filling method, it can not only be carried out only in the necessary areas around the leakage point, but also
Relatively coarse-grained chemical solutions can be injected at low pressure, and grouting can be performed effectively while checking the injection status of the chemical solution, which is an outstanding feature in permanently preventing leaks in sewer pipes buried underground. This is expected to have significant technical and economic effects.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway front view showing the grout backing installed in the sewer pipe, Fig. 2 is a longitudinal sectional view showing the relative position of each member in the construction method of the present invention, and Fig. 3 is an enlarged view showing a part of the main part thereof with a cutaway. In the diagram, 1... Sewer pipe, 2... Grout backing, 3... Jacket, 4...
- Grout pipe (suction pipe), 5...Drain pipe, 6...Drain hose (grout hose).

Claims (1)

[Scope of Claims] 1. A grout backing with a concave cross section that encloses the leakage point is tightly fixed in an annular manner to the inner surface of the sewer pipe, and the other end of the drain hose that opens into the inner groove is connected to a vacuum pump,
The sewage pipe is capable of suctioning and discharging accumulated water around the sewage pipe through the inner groove of the grout backing, while injecting and hardening an appropriate chemical solution through a grout pipe bored outside the sewage pipe. Water leakage treatment mud 2 The upper end of the suction pipe drilled from the ground surface to the outside of the sewer pipe is connected to a vacuum pump, and the accumulated water around the sewer pipe is sucked out.
While making it possible to drain water, a grout backing with a concave cross section that encloses the leakage point is tightly fixed in an annular shape to the inner surface of the sewer pipe, and an appropriate chemical solution is injected and hardened through a grout hose that opens into the inner groove. Water leakage treatment method for sewage pipes.