JPH01169091A - Keeping of facing water pressure in muddy water method - Google Patents

Abstract

PURPOSE:To prevent the escape of mud by a method in which concentrated muddy substance in a branched device with a muddy water concentrator is stored in a mud regulator and then injected into the facing when the water pressure of the facing is lowered to form a mud film or permeation-improved area. CONSTITUTION:A branched device 8 with a muddy water concentrator 7 is set partly on a mud-sending tube 4 or mud discharge tube 5, and a concentrated muddy water discharging tube 10 is connected to a mud regulator 9. An injection tube 12 with a water injection pump 11 is connected to the middle of a shield machine 1, and the tip of the tube 12 is connected to the front of a cutter 13. Muddy water from the device 8 is passed through the concentrator 7, dilute muddy water is returned to the tube 4 or the tube 5, and concentrated muddy substance is stored in the regulator 9. When the water pressure of facing is lowered, high concentration of muddy water of muddy substance is injected to facing from the face plate 14 of a cutter 13 to raise the water pressure of facing to a set pressure. A permeation-improved area is formed thereby to prevent the escape of mud, and when the water pressure rises, mud is discharged by an urgent pressure-reducing valve 16 to lower the pressure to a set pressure.

Description

[Detailed Description of the Invention] [Industrial Field of Application] In the muddy water shield method, this invention makes it possible to stabilize the face by always maintaining the mud water pressure at the face at a set pressure.

[Conventional technology]

In the mud shield method, it is extremely important to maintain the mud water pressure in order to stabilize the face, and normally the mud water pressure at the face is maintained by regulating the flow of the mud pump, but in this method When adding pipe connections.

The pressure may drop to natural water pressure when the propulsion jack retreats, when the mud pump malfunctions, or when the amount of lost mud increases due to changes in the soil quality of the ground.

Furthermore, when a mud drain pipe or the like is blocked, the mud water pressure at the face increases rapidly. It had the following drawbacks.

[Problem that the invention seeks to solve]

Even if mud water pressure at the face is maintained by adjusting the mud flow in the mud shield construction method, problems may occur when adding mud pipes, when the propulsion jack backs up, when the mud transport sonde malfunctions, or when land trade in the ground changes. This invention attempts to solve the problem that the water pressure may drop to natural water pressure when the amount of lost sludge increases, and the problem that the face water pressure suddenly increases when the sludge pipe is blocked. It is.

[Means for solving problems]

In a device equipped with a mud feeding pipe and mud draining pipe in order to keep the pressure in the chamber of a shield machine constant, a branching device with a muddy water thickening device is installed in a part of the mud feeding pipe or mud draining pipe, and a muddy water thickening device is installed. At the same time, connect the thickened mud water drainage pipe to the mud conditioning device and connect an injection pipe with a swirling mud water injection pump between the mud conditioning device and the shield machine, and connect the tip of the injection pipe to the front of the cutter with a connection opening. After branching the muddy water using a branching device, the diluted muddy water is passed through a muddy water concentrating device and returned to the mud feeding pipe or mud draining pipe. The compressed mud is stored in a mud conditioning device, and when the water pressure at the face decreases, the concentrated mud water injection pump injects highly concentrated mud or mud from the face plate of the cutter toward the face to increase the mud water pressure at the face. By increasing the pressure to a set level and forming a mud film on the face or an area to improve infiltration into the ground, we aim to prevent mud loss, and when the water pressure at the face rises, an emergency pressure relief valve is activated to remove mud. , the gap between the peaks was solved by lowering the pressure to the set pressure.

[Effect]

After the mud water is branched by a branching device that has a mud water concentrator installed in a part of the mud feed pipe or mud drainage pipe, the dilute mud water is returned to the mud feed pipe or mud discharge pipe through the mud water concentrator and is concentrated. Sludge is stored in the mud adjustment device, and a drop in water pressure at the face is detected by a face water pressure detector, and when the water pressure at the face drops, the concentrated mud injection pump is activated to remove highly concentrated mud or mud from the face plate of the cutter. This method aims to prevent mud slippage by injecting mud into the face, increasing the mud water pressure at the face to a set pressure, and forming a mud film on the face of the face or an area to improve penetration into the ground.

Furthermore, when the water pressure at the face rises, an emergency pressure relief valve attached to the bulkhead of the shield machine is operated to remove mud and maintain the set pressure.

〔Example〕

Adjustment tank (
3) and the mud removal pipe (5) connected to muddy water treatment equipment (not shown) provided on the ground are connected and opened. A telescoping pipe (6) that moves together with the shielding machine (1) is installed behind the shielding machine (1), and muddy water is concentrated in the - part of the intermediate sludge removal pipe (5) between the shielding machine (1) and the telescoping pipe (6). A branching device (8) having a device (7) is provided. A mud conditioning device (tank) (9) is installed at the bottom of the muddy water thickening device (7), and the concentrated muddy drainage pipe (10) installed in the muddy water thickening device (7) is used as a mud conditioning device! The opening is connected to ff1 (9). The injection pipe (12) equipped with the mud conditioning device (9) IcVi concentrated mud injection tube 7' (11) is connected and opened, and the tip of the injection pipe (12) is branched to connect to the face plate (14) of the cutter (13). ) with connecting openings in the center and in multiple locations. Also, a face water pressure detector (15) is installed on the upper part of the partition wall (2).
) detects a drop in water pressure at the face and turns on the concentrated mud injection pump (11
) is set to operate automatically. At the top of the bulkhead (2), a discharge pipe (17) equipped with an emergency pressure relief valve (16) is connected and opened, and the tip of the discharge pipe (17) is opened with a mud control device e (9) IcJ. . Pulp (1
8) Concatenation with ? (19) and pass'f (20
) is provided with a pulp (21) for maintaining face water pressure. Note that % (22) is a Vi slurry pump, and (23) indicates pulp. After dividing the muddy water in such a device, the diluted muddy water is passed through the muddy water ln&l1vt] (7) and returned to either the mud feeding/discharging pipe (4) or (5), and the concentrated mud is sent to the mud conditioning device ( 9).

When a drop in water pressure at the face is detected by the face water pressure detector (15), the concentrated mud water injection sonde (11) is automatically activated to remove the noisy mud water or muddy material from the wall (13).
) is injected from the face plate (14) toward the face, increasing the face mud water pressure to the set pressure, and forming a mud film on the face or an area to improve penetration into the ground, thereby preventing mud slippage. It is. Furthermore, when the face water pressure detector (15) detects an increase in face water pressure, the emergency pressure relief valve (16) is automatically activated to drain mud and maintain the face water pressure at the set pressure.

〔effect〕

■When the water pressure at the face drops, the water pressure can be instantly restored by injecting into the face.

■When the face water pressure increases, the pressure can be immediately reduced by operating the emergency pressure relief valve.

■Sludge loss can be prevented by forming a mud film or a permeation improvement area on the face.

■It is economical and efficient as it does not require on-ground mud production equipment or piping to the shield machine.

■The concentration of sludge can be changed freely by adjusting the thickening device.

■Even when mud is lost, normal mud water can be used for transporting mud, so the load on the fluid transport system is small.

[Brief explanation of the drawing]

The figure is a system diagram of an embodiment of the present invention. Patent applicant: Toda Construction Co., Ltd. 1 ga-drop

Claims (1)

[Claims] In a device equipped with a mud feeding pipe and mud draining pipe in order to keep the pressure in the chamber of a shield machine constant, a branching device with a muddy water thickening device is installed in a part of the mud feeding pipe or mud draining pipe, and a muddy water thickening device is installed. Connect and open the thickened mud water drainage pipe to the mud conditioning device, connect an injection pipe having a thickened mud water injection pump between the mud conditioning device and the shield machine, and connect and open the tip of the injection pipe to the front of the cutter. After branching the muddy water using a branching device, the diluted muddy water is passed through a muddy water concentrating device and returned to a mud feeding pipe or mud removal pipe, and the concentrated mud is stored in a mud conditioning device.
When the water pressure at the face decreases, the concentrated mud water injection pump injects highly concentrated mud water or mud from the face plate of the cutter toward the face, increasing the face mud water pressure to the set pressure, and infiltrating into the mud film or the ground on the face. A method for maintaining water pressure at a face in a muddy water construction method, which is characterized by preventing mud slippage by forming an improved area, and when the water pressure at the face rises, the mud is drained by operating an emergency pressure relief valve and the pressure is lowered to a set pressure.