Large-span tunnel surrounding rock aging safety degree analysis method considering joint creep

Abstract

The invention discloses a large-span tunnel surrounding rock aging safety degree analysis method considering joint creep, which comprises the following steps: defining a nonlinear sticky kettle element, providing a nonlinear Xiyuan ubiquitous-joint strain softening creep model combining joints with creep, and describing the strength parameter softening degree of a rock mass after the joints yield; and deriving a ZSIsu piecewise function of the model. According to the method, the nonlinear Xiyuan ubiquitous-joint strain softening creep model is established through the introduced nonlinear sticky kettle element, the characteristic that the accelerated creep stage of the jointed rock mass cannot be simulated in a traditional model is made up, the joint and creep are combined, the characteristics of the jointed rock mass are fully reflected, meanwhile, the attributes of the joint and the rock mass are considered, and rock mass joint characteristics and engineering practice can be better reflected. Meanwhile, a ZSIsu piecewise function of the model is deduced in combination with unit state indexes, quantitative control over all stages of tunnel excavation is achieved in the large-span underground excavation tunnel construction process, and safe construction is effectively guided.

Description

technical field [0001] The invention relates to the construction field of long-span underground excavation tunnels, in particular to a method for analyzing the time-effect safety degree of surrounding rocks of large-span tunnels in consideration of joint creep. Background technique [0002] During the construction of long-span tunnels, the deformation of the rock mass on both sides of the tunnel structure is not only related to space effects, but also often related to time. Under the action of environmental, geological and engineering factors, the mechanical behavior, constitutive relationship, instability and failure laws of rock and soil materials and rock mass structures and time intervals. For example, the deformation of the main structure of the tunnel is not obvious at the initial stage of excavation, but with the increase of time, the deformation of the tunnel becomes more and more serious, and even instability and damage occur. Therefore, it is of great theoretical ...

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Problems solved by technology

[0004] The present invention provides a time-effective safety analysis method for the surrounding rock of a large-span tunnel considering joint creep, so as to overcome the technical problem that the current research method cannot simulate the characteristics of the accelerated creep stage of the rock mass and cannot fully reflect the characteristics of the joint rock mass

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