Construction method for tool changing under pressure in shield of water-rich silty soil and silty sand stratum under station tracks of railways

Abstract

The invention discloses a construction method for tool changing under pressure in a shield of the water-rich silty soil and silty sand stratum under station tracks of railways. The construction method comprises the following steps of: carrying out reinforcement on a soil body at a tool changing position by adopting a high-pressure rotary jet pile; inspecting whether holes exist on the ground surface in the soil reinforcing area, and adjusting the tunneling posture and the tunneling direction of a shield machine; after reinforcing soil enters a cutting port of the shield machine, reducing the pressure of a soil warehouse, and adjusting construction parameters; injecting bentonite into the soil warehouse of the shield; determining an air pressure value, and determining a tool-changing air pressure value in the soil warehouse according to the obtained water-soil pressure value; and finally, clearing the warehouse, and reducing the pressure; and workers enter to change a tool, and after tool changing, the shield machine restores the tunneling working state. The construction method disclosed by the invention has the advantages that the risk that water-rich soft soil is easy to flow to cause collapse when the tool is changed under pressure in tunnel shield construction of the water-rich silty soil and silty sand stratum is overcome, and the operation safety of upper railways is ensured.

Description

technical field [0001] The invention relates to the technical field of shield tunneling, in particular to a construction method for shield tunneling under pressure in a water-rich silty soil silt formation under a railway track. Background technique [0002] "Shield tunneling method construction" is a highly mechanized and automated tunneling construction method. Since the 1960s, western developed countries have widely applied this technology to the construction of urban subways and large urban drainage tunnels. With the rapid development of urban rail transit, subway shield technology has been widely used. The shield method construction uses the shield machine as the tunneling equipment, uses the shield shell of the shield machine as support, cuts the soil with the front cutter head, pushes the shield machine forward by the jack, and assembles and prefabricates it on the excavation surface. The segment is used as lining to form a tunnel construction method. During the tun...

AI Technical Summary

Problems solved by technology

During the tunneling process, the shield machine uses the cutter to cut soil and break the rock. After the long-distance tunneling, the shield machine needs to replace the cutter due to the wear of the cutter, and the tool replacement under pressure is a high-risk operation, especially in the construction environment for railways. The water-rich silty soil and silt-sand strata under the track, if not carefully controlled, may cause the ground collapse of the upper railway track due to excessive ground subsidence, seriously affecting the safety of railway operation

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