JPS5824094A - Mud pressure shield drilling engineering method using latent curable muddy substance - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a Tonosho-based shield construction method for excavating a tunnel using mud.

The shield construction method is often used in the construction of subways, underground tunnels, sewers, etc. because it causes less construction pollution to nearby residents and less impact on road traffic due to tunnel construction.

Among these, the Tonosho shield method generally involves filling a cutter drum with earth and sand cut from the face using a cutter to prevent the face from collapsing, and transporting the earth and sand using a screw conveyor, etc., and then assembling segments to construct a tunnel. However, compared to the pressurized air shield method, it has the advantage of providing a better working environment and does not require auxiliary construction methods, and compared to the muddy water pressurized shield method, it requires soil separation equipment and muddy water treatment equipment. It has the advantage of not being harmful.

However, with the conventional Tonosho shield method, when excavating the Tonosho face, depending on the soil quality of the excavated soil, arching of the earth and sand may occur inside the cutter drum, or earth and sand may adhere to the cutter drum, increasing cutting resistance against the face. There were many cases where it became impossible to dig. In addition, backfilling material such as cement mortar is usually injected into the backfilling area between the other pile and the segment that occurs during shield excavation. It often went around the cutter face and hardened (-IN), hindering shield excavation.

The present invention has been made to solve the above problems,
The purpose of this is to prevent the cutting resistance against the face from increasing due to the soil quality of the excavated soil, and to prevent the backfill material injected into the backfill area from firmly adhering to the tail packing and cutter face and hardening. The purpose of the present invention is to provide a Tonosho-based shield excavation method that can efficiently excavate.

Embodiments of the present invention will be described below with reference to the drawings.

/ is a Tonosho type shield excavator, and tsu is a cutter drum installed in the front part of the excavator /. The cutter drumco is supported by a seal 3 and a rotary white plate I receiver, and is rotationally driven by a drive motor t via the left side of the transmission mechanism. The cutter drum is pivoted to a partition g fixed to the shield skin plate 7 at the rear. 9 is a screw conveyor. The tip opening f91s of the screw conveyor 9
10 is pushed into the cutter drum through the partition g. // is a scraping board that scrapes up excavated soil.
They are fixedly installed on the peripheral wall surface of the cutter drum at appropriate intervals.

A plurality of injection nozzles 13 are provided on the cutter face 7.2 on the front side of the cutter drum toward the face.

The injection nozzle /3 is connected to branch pipe 7 /1% intermediate pipe / left, supply pipe /7 via swivel joint /A
is connected to. The partition wall g is provided with a plurality of injection nozzles /g toward the inside of the cutter drum co, and is connected to a supply pipe /9. In addition, the segment 20 is injected 0.2)1. All are provided,
Each is connected to a supply pipe 221.2.27.

The supply pipes /9, 2.2 are connected to seven rear supply pumps P (not shown).

Further, the supply pipe: 1.2/ is connected to a supply pump p/ that is different from the supply pump P (not shown).

, 23 is shield propulsion jack, 21/-1, 2 left, 2
B, the valve 1.2g is the earth and sand discharge port 1.29 is the tail packing.

In addition, A is a face and B is a backfill part.

Next, the operation according to the present invention will be explained according to the drawings.

The Tonosho-type shield tunneling machine 1 is propelled toward the face A side by a shield propulsion jack 23, one end of which is fixed to the tunneling machine 1, by taking a reaction force from a segment 20 assembled at the rear of the tunneling machine 1. .

The earth and sand excavated from the face A is taken into the cutter drum by the cutter face 7.2 on the front surface of the rotatably driven cutter drum. On the other hand, the injection nozzle 13
Latent hardening mud is injected by a supply pump P (not shown) toward the face A, and from the injection nozzle/g toward the excavated soil taken into the cutter drum co. be done. Furthermore, from injection 0.2/, there are other peaks and segments that occur with the propulsion of the excavator l, 20
The supply pump P (not shown) toward the backfilling part B between
The slurry is injected by injection. Here, an example of the latent hardening slurry used is one in which clay such as blast furnace slag powder or bentonite is suspended in water, and the blast furnace slag powder reacts with the alkaline substance described below. Clays such as bentonite provide good stability (dispersibility) of the suspension. In addition, examples of formulation of the suspension are shown in Table 1.

Further, the volume of mud injected into the face A1 cutter drum varies depending on the soil quality of the excavated soil, and is approximately 0 to SO% of the excavated soil.

In this way, the cutting resistance during mechanical excavation on the face A does not increase, and while the stability of the face A is maintained, the excavated soil taken into the cutter drum is mixed with the mud and the scraping of the rotating cutter drum λ. The mixture is stirred and mixed by the blade plate and transferred to the tip opening 10 of the screw conveyor. At this time, the fluidized excavated earth and sand is conveyed to the screw conveyor 9 without causing any arching phenomenon or adhesion within the cutter drum. After that, the excavated soil is removed from the soil discharge port 2.
g, and then transported out of the mine by means of evacuation such as a belt conveyor or trolley.

On the other hand, the muddy material injected into the backfilling part B is also filled with the face A, (l!tl), so it stays there without going around. 0 people.
An alkaline substance is injected from 27' by a supply pump p/ (not shown).

In this way, the mud remaining in the backfilling portion is sprayed and agitated with the alkaline substance, becomes highly alkaline, and begins to harden.

The hardened mud does not have the strength of conventional backing materials such as cement mortar, and does not strongly adhere to the tail packing or cutter face.

Here, milk of lime, water glass, etc. are good examples of the alkaline substance used. Table 7 above shows milk of lime (20% liquid).
The results show the strength results when 2S% of each blend of the slurry was mixed. In addition, the amount of alkaline material injected is small, approximately 10 to SO% of the volume of the mud remaining in the backfilling portion, and there is little circulation toward the face side.

2. As described above, according to the present invention, a latent hardening mud is injected into the face and the excavated soil taken into the cutter drum, thereby improving the hardness of the face during mechanical excavation. In addition to reducing the resistance, it is possible to prevent the occurrence of arching of the excavated earth and sand in the cutter drum, and to prevent the excavated earth and sand from accumulating in the cutter drum. , the inside of the cutter drum and screw conveyor can be carried out smoothly.

In addition, by injecting an alkaline substance into the backfilling part filled with the latent hardening mud, the mud in the backfilling part is hardened, and the conventional backfilling material such as cement mortar is used. Because it has no strength and does not adhere strongly to the tail gasket or cutter face,
You will not be unable to dig into the shield.

Table - Example of blending of mud and strength after hardening

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a Tonosho type shield excavator according to the present invention. / : Tonosho type shield 2 Two-cutter drum excavator g = bulkhead 9 : Screw conveyor l cutter face /3 : Injection nozzle /7: Supply pipe 7g: Injection nozzle /9=
Supply pipe 20: Segment 2/, 2': Inlet Yuko, n': Supply pipe 29: Tail packing A: Face -B: Backfill section Patent applicant Obayashi Corporation Agent Jun Okada Nie-Roku

Claims (1)

[Claims] In the Tonosho shield excavation method, a latent hardening mud is injected into the face and cutter drum, and into the backfill area that occurs between the segments that are assembled behind other piles as the shield excavates. An earth pressure shield excavation method using latent hardening mud, characterized by excavating, and then injecting an alkaline substance into the backfill to harden the mud in the backfill.