JPH04202998A - Earth pressure system shielding method and mud-adding material for it - Google Patents

Abstract

PURPOSE:To apply an earth pressure system shielding method even to the gravel ground under high water pressure by blending water and macromolecule polymer system silicate at a given proportion to make a mud-adding material, and injecting the mud-adding material into a working face side of a shielding machine. CONSTITUTION:A mud-adding material is made to have viscosity of about 150-250cps to the viscous ground by blending an about 5-10kg main material of inorganic system nacromolecule polymer silicate powder to 1000l water, and viscosity of about 250-850cps for the sand ground by blending the about 10-50kg same main material to 1000l water. Then the mud-adding material of a planed quantity is pressure-injected in a chamber C of a shielding machine B and a working face side, and the working face is cut and also earth and sand are taken in the chamber C. This excludes water among soil grains with the mud-adding material, and fills gaps among the soil grains with the mud- adding material, enabling the application of a shielding method even to the sand ground under high water pressure.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an earth pressure shield construction method applied to tunnel construction work in urban areas, etc., and a muddying material for the same construction method.

(Conventional technology) The earth pressure shield construction method consists of muddy water made by adding water to bentonite, clay, etc. from the front of the shield machine, and muddy material is injected into the face of the face and pressurized to ensure the stability of the face. This is a method of constructing a tunnel by excavating a tunnel-shaped hole and sequentially assembling segments into a ring shape inside the hole.

The excavated earth and sand will be discharged from the mine to the surface, where it will be disposed of.

However, since hentonite is used as the muddying material, the earth and sand discharged from the shield machine is treated as industrial waste, and the concentration of wastewater is as high as 0-11, which requires neutralization treatment. There's a problem.

For this reason, in recent years, muddying materials containing nonionic cellulose esters, powdered clay, and water have been developed to prevent them from being treated as industrial waste.

(Problems to be Solved by the Invention) The above-mentioned non-polluting muddying material can ensure the stability of the face in general ground, but it has a small specific gravity of about 1.0-3, and is of a water-impermeable type. Because of this, water pressure resistance is low.

For this reason, it is difficult to apply the earth pressure shield method to sandy or gravelly ground under high water pressure, and there are also problems such as the need for soil removal treatment because the muddy material weakens the discharged soil. was there.

The present invention has been proposed in view of the problems existing in the prior art, and includes an earth pressure shield construction method that allows tunnels to be constructed without pollution and without the need for handling industrial waste, and an earth pressure shield construction method for the construction method. The point is to provide materials.

(Means for Solving the Problems) In order to achieve the above object, according to the earth pressure shield construction method according to the present invention, a mud material containing water and a high molecular weight silicate is used in a shield machine. It is injected into the front face side of the

Further, the muddying material according to the present invention is constituted by blending water and a high molecular weight silicate.

(Function) According to the present invention, as described above, by injecting and pressurizing the paste-like muddying material with high specific gravity, which is a mixture of high-molecular-weight polymer silicate and water, the muddying material has a specific gravity. Since this is large, the interstitial water between the soil particles can be easily removed, and the interstices between the soil particles can be completely filled with the paste-like muddying material.

As a result of (2), an impermeable ground is formed in front of the face, and the stability of the face is sufficiently ensured even on sandy or gravelly ground under high water pressure.

In addition, the earth and sand cut by the cutter of the shield machine is taken into the chamber, mixed with the muddy material injected into the chamber, and discharged through the cut earth and sand carrying member. Since the mudding material is stable, it is taken into the chamber without increasing the water content ratio, and because the mudding material has good fluidity, the plastically fluidized soil is discharged from the discharge member. Ru.

Therefore, the discharged earth and sand can be easily carried outside the mine, and can be carried off-site as is.

(Example) The present invention will be described below with reference to Examples.

Manufacture muddy material according to the following procedure according to the target ground.

B. For cohesive soil, mix 5-10 kg of the main material made of inorganic high molecular weight silicate powder to 1,000 liters of water to achieve a viscosity of 150-250.
Adjust the cps muddying material. (Injection rate: approximately 10%) For sandy, gravelly ground, mix 10-50 kg of the above-mentioned main material with 1,000 liters of water to add mud with a viscosity of 250-8500 cps. Adjust.

(Injection rate, approximately 10-30%) Figure 1 shows the work flow diagram when the amount of mud added is small, such as for small and medium-sized shields, and the main material ordered and adjusted to factory 1 is transported to the planned usage amount. Next, the same main material is kneaded with water at high speed in a high-speed mixer 3, and the slurry material adjusted in the same mixer 3 is transferred to an agitator 4. - The axial screw pump 5 pumps the material into the mine A through the pipe 6, and stores it in the relay tank 7 connected to the shield machine B.

In the figure, 8 is the bulkhead of the shield machine B, and C is the chamber.A cutter 9 cuts the earth and sand from the face, and the muddy material is poured into the face and the chamber C by injection pipes 10^ and 10B connected to the tank 7. The face is cut while applying pressure, and the cut earth and sand are taken into the chamber C.

The screw conveyor 11 is filled with the cut soil mixed with the muddy material, the gate 12 of the conveyor 11 is opened, the discharged soil is transferred to the belt conveyor 13, and the steel car 1 is further transferred to the belt conveyor 13.
In this way, the earth and sand are continuously removed in an amount corresponding to the thrust amount of the shield 1fstB, and transported to the lower part of the shaft 15 via the steel car 14, and the discharged earth and sand is hoisted up by a crane and dumped through the hopper 16 at the upper part of the shaft 15. Loaded onto truck 17,
The soil is to be removed at the soil dump site 18.

The middle part in the figure is the segment, and E is the other part.

(Effects of the invention) According to the present invention, by mixing water and high-molecular polymer silicate to prepare a muddy material and injecting the muddying material into the face side, construction is difficult in the past. This makes it possible to apply the Tonosho-based shield construction method to sandy and gravelly ground under high water pressure, which has previously been subject to high water pressure, greatly expanding the scope of application compared to conventional construction methods.

In addition, since the discharged soil is plastically fluidized by the muddying material, it is easy to carry it out of the mine.Furthermore, the muddying material uses only a small amount of the main material, high molecular weight silicate, and is resistant to water. Since the adjustment can be made by simply mixing, the plant equipment for making mud can be smaller than before, and it has many advantages, such as making mud making work and management extremely easy.

[Brief explanation of the drawing]

FIG. 1 is a work flow diagram of an embodiment of the earth pressure shield construction method according to the present invention. A...Underground, B...Shield machine, C
...Chamber, 2...Sludge production plant equipment,
3...High speed mixer, 4...Agitator-1
5...Screw pump, 6...Piping, 7...Relay tank, 9...Cutter, 10A, 10B
...Injection piping, 11...Screw conveyor. Agent: Patent attorney Shige Okamoto (1 person)

Claims (1)

[Claims] 1. An earth pressure shield construction method characterized by injecting a muddying material containing water and a polymeric silicate into the front face side of a shield machine. 2. A muddying material for earth pressure shield construction method, characterized by being made by blending water and high molecular weight silicate.