Safety analysis method for fluid-solid coupling of all-over joints of shield excavation face

Abstract

The invention provides a shield excavation face spread joint fluid-solid coupling safety degree analysis method which comprises the steps that a spread joint strain softening model of an excavation face is established, a rock mass of the excavation face is divided into a plurality of units, and each unit is composed of a rock block and a joint; judging an elastic stage and a yield stage of the rock mass and the joint; safety calculation is conducted on the rock blocks and joints in the elastic stage / yield stage; selecting the rock mass / joint with the minimum safety degree in the elastic stage / yield stage; permeability coefficient calculation is conducted on the rock mass / joint with the minimum safety degree; substituting the safety coefficient into fluid-solid coupling numerical calculation to carry out iterative calculation so as to monitor the dynamic change of the permeability coefficient; by calculating the safety degree of each unit of the rock mass and determining the permeability coefficient of the rock mass, the shield excavation surface local stability monitoring of rock mass fluid-solid coupling is realized, the permeability coefficient dynamic change of the rock mass spread over joint characteristics is clearly reflected, and the shield excavation surface analysis accuracy under the spread over joint condition is improved.

Description

technical field [0001] The invention relates to the field of fluid-solid coupling calculations, in particular to a method for analyzing the safety degree of joint fluid-solid coupling throughout a shield excavation face. Background technique [0002] The stability of the excavation face of shield tunneling is a key issue in shield tunneling construction and a prerequisite for selecting reasonable shield construction parameters; especially in the case of abundant groundwater and significant distribution of surrounding rock joints, the stability of shield tunneling face There is still a lack of reasonable quantitative calculation methods for analysis; traditionally, strength reduction methods, plastic zone analysis methods, and displacement analysis methods are generally used. It reflects that the stability changes with the space, so it brings a large error. [0003] In most cases, the surrounding rock of the shield tunnel is rich in joints and is in the groundwater; the exca...

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Problems solved by technology

[0002] The stability of the excavation face of shield tunneling is a key issue in shield tunneling construction and a prerequisite for selecting reasonable shield construction parameters; especially in the case of abundant groundwater and significant distribution of surrounding rock joints, the stability of shield tunneling face There is still a lack of reasonable quantitative calculation methods for analysis; traditionally, strength reduction methods, plastic zone analysis methods, and displacement analysis methods are generally used. It reflects that the stability changes with the space, so it brings a large error

[0003] In most cases, the surrounding rock of the shield tunnel is rich in joints and is in the groundwater; the excavation surface of the shield tunnel is affected by joints and groundwater, and there is a complex fluid-solid coupling effect; the traditional analysis method has the following limitations: 1) Using the overall stability analysis method of the excavation face, the spatial distribution of the safety degree in the excavation face cannot be obtained; 2) The safety analysis of the fluid-solid coupling of the face does not consider the joint effect and the change of the permeability coefficient

The above problems affect the correct analysis of the stability of the shield excavation face and the correct selection of shield construction parameters under this special condition

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