Calculation method for surrounding rock stress and displacement of shallow tunnel with cavity under gravity

Abstract

The invention provides a method for solving the surrounding rock stress and displacement of a shallow buried tunnel in a cavity-containing stratum under the action of gravity. Including: calculation of the complex potential analytical function of the surrounding rock stress and displacement of the shallow tunnel under the stress release load of the gravity field; calculation of the additional surface force caused by the tunnel on the boundary of the cavity; calculation of the surrounding rock stress and displacement of the cavity under the action of the additional surface force Displacement complex potential analytical function; calculate the additional surface force caused by the cavity on the tunnel boundary; calculate the surrounding rock stress and displacement complex potential analytical function of the tunnel under the action of the attachment surface force; repeat the above process until the set stop condition is met ; Superimpose the complex potential analytical functions obtained in previous iterations to obtain the final complex potential analytical function of the surrounding rock stress and displacement of the shallow tunnel, and the final calculation formula of the surrounding rock stress and displacement. The method of the invention can consider the interaction between the tunnel and the cavity; can consider the stress release of the gravity field during the excavation process of the tunnel, and has high solution efficiency and good solution accuracy.

Description

technical field [0001] The invention relates to the technical field of urban underground tunnels, in particular to a method for solving the stress and displacement of the surrounding rock of shallow-buried tunnels in strata containing cavities under the action of gravity. Background technique [0002] my country is in the process of rapid urbanization, the population of urban core areas is growing rapidly, and the traffic pressure faced by cities is becoming increasingly prominent, and even becomes a major bottleneck factor for urban development. As an efficient, punctual, and large-capacity transportation mode, the subway is widely used in major cities in China, and the construction of subway tunnels will greatly increase in the future. City Metro Tunnel has the following features: [0003] ① Generally, the buried depth is relatively shallow, and gravity is the main external load. [0004] ②The formation deformation generated during the construction process can easily be ...

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Problems solved by technology

[0004] ②The ground deformation generated during the construction process is easily transmitted to the surrounding buildings (structures), thereby endangering the safety of the surrounding buildings (structures)

[0007] ① When using the empirical prediction method, the main parameters need to be determined manually, which is greatly influenced by the experience of engineers. The empirical method can only predict the formation deformation, and the empirical method cannot reveal the mechanical mechanism of the formation deformation

[0008] ②Although the numerical simulation method can fully display the surrounding rock stress and displacement, the modeling process of the numerical simulation method is slow, the simulation parameters and methods are subject to the subjective influence of engineers, the repeatability is poor, and the numerical calculation takes a long time , cannot quickly evaluate the project

[0009] ③Existing theories are mostly aimed at a single tunnel, rarely considering the influence of stratum cavities, and rarely considering the gravity factor

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