Construction method of rock structural plane damage statistical constitutive model considering size effect

Abstract

The invention discloses a construction method of a rock structural plane damage statistical constitutive model considering a size effect, which comprises the following steps of: firstly, simplifying astructural plane into an equivalent thin layer, and determining damage variables according to the number of damaged mesoscopic microelements and the total number of the mesoscopic microelements in the thin layer; secondly, obtaining a damage probability density function of the mesoscopic unit body; then, determining a reasonable damage initial stage, simulating the structural plane load condition, and obtaining a statistical damage constitutive model of the structural plane under the shearing effect; secondly, according to stress balance in the shearing process, determining the relation amongnominal shearing stress, effective shearing stress borne by the undamaged infinitesimal body and shearing stress borne by the damaged infinitesimal body, and obtaining a damage evolution model and astructural surface shearing deformation damage constitutive model of the structural surface in the shearing deformation process; determining parameters m and u0 of the structural plane shear deformation damage constitutive model, and establishing a structural plane shear constitutive model considering the size effect based on the nonlinear relationship between the parameters and the size; finallyverifying the correctness.

Description

technical field [0001] The invention belongs to the research field of constitutive models of rock structural planes, and in particular relates to a construction method of a damage statistical constitutive model of rock structural planes considering size effects. Background technique [0002] The existence of structural planes is the root of the difference between rock mass media and other media, and it is also an important factor affecting the mechanical properties of rock mass. Establishing a shear constitutive model that can accurately simulate the whole process of shear deformation and failure has always been a hot spot in rock mechanics research. Since the 1960s, many scholars have carried out research work and established many structural surface constitutive models. Representative ones include: pure linear elastic constitutive models such as Goodman model, Saeb-Amadei model; nonlinear models such as Barton-Bandis model, Grasselli model, CSDS model; elastic-plastic incr...

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Problems solved by technology

These research results have promoted the understanding of the shear size effect of structural planes. However, due to the complex mechanical behavior of rock materials, the mechanism and manifestation of the size effect have not been fully elucidated. Looking at the existing shear constitutive models, few A model with comprehensive consideration of size effect and post-peak damage softening characteristics

How to correctly and comprehensively reflect the shear behavior of rock mass structural planes under various sizes and establish a shear constitutive model considering the size effect of structural planes remains to be explored

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