A test method for simulating passive failure of excavation face of shallow buried shield tunnel

Abstract

The invention discloses a test method for simulating passive damage to a shallow-buried shield tunnel excavation surface. The test method comprises the following steps that after filling soil in a model box is completed, the initial readings of a miniature water and soil pressure monitoring element on a cutter head of a model shield machine, a displacement meter in a soil body in front of the excavation surface, and a displacement meter monitoring element on the ground surface are recorded; the model shield machine is placed close to an opening of the model box, and excavation is prepared; when the model shield machine excavates to a predetermined position, a jacking motor, a cutter head motor and an auger motor are closed at the same time; a test of passive damage to the excavation surface is started; the cutter head motor is started, the jacking motor is opened at the same time, the auger motor is not switched on, and the value of each monitoring element is recorded in real time, thevalue includes a water and soil pressure value on the cutter head, a displacement value in the soil body in front of the excavation surface, and displacement amount of the surface soil body; and thenthe cutter head motor and the jacking motor are closed to measure the values of the monitoring elements. The test method is closer to the process of passive damage to the excavation surface of a realshield machine, and the model test results are more scientific and accurate.

Description

technical field [0001] The invention relates to the field of tunnel engineering model tests, in particular to a test method for simulating passive damage to excavation surfaces of shallow-buried shield tunnels. Background technique [0002] In recent years, with the acceleration of my country's urban construction process, the ground space has become saturated, and traffic congestion has seriously restricted economic development. In order to alleviate the pressure of ground traffic, urban subway construction came into being. Compared with other methods such as drilling and blasting, the shield method has the advantages of less impact on ground traffic; high degree of mechanization, fast construction speed; bad weather has little impact on shield method construction, etc., and is widely used in the construction of urban subway tunnels middle. [0003] Due to the limitations of ground construction and surrounding environment, the technical requirements for shield tunneling ar...

AI Technical Summary

Problems solved by technology

There have been many tests in China to simulate the active failure of the tunnel excavation face, but there are very few model tests on the passive failure of shallow shield tunnels.

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