A Method of Establishing Rock Damage Constitutive Model Based on the Principle of Minimum Energy Dissipation

Abstract

The invention discloses a method for establishing a rock damage constitutive model based on least energy consumption principle, the method is as follows: a damage evaluation equation is deduced based on the least energy consumption principle; the rock damage constitutive model is established in a continuum damage theoretical framework by combination of the damage evaluation equation; the theoretical relation between deformation parameters of and parameters of the model is deduced, and conventional triaxial compression tests of the rock under different confining pressures can be performed to obtain strain-axial and radial strain relation curves of a specimen under corresponding confining pressures and mechanical strength parameters and strain parameters of the rock specimen; and by experimental results damage threshold can be determined, and the model parameters can be identified. The damage threshold in the rack damage evolution law can be determined by combination of the model and the dilatation startup property of the rock, the proposed model can better reflect the nonlinear mechanical behavior of a rock material under complex stress conditions, the constitutive model influenced by the damage threshold has higher fitting precision on the post-yielding section of the rock material, and the constitutive model has great reference significance and application value to the safety analysis of rock engineering under the complex stress conditions.

Description

technical field [0001] The invention relates to a method for establishing a rock damage constitutive model based on the principle of minimum energy consumption, and belongs to the technical field of geotechnical engineering. Background technique [0002] The long geological evolution process and the complex three-dimensional stress environment have produced a large number of discontinuous and irregular micro-cracks, micro-cracks, joints and other micro-defects inside the rock. The mechanical response of micro-defects under different stress conditions determines its uniqueness. Significant macroscopic nonlinear mechanical properties. The practice of excavating a large number of high rock slopes and large underground caverns shows that the study of rock mechanical properties is particularly important for the safety design and stability analysis of geotechnical structures. Therefore, the establishment of a constitutive model that can reflect the nonlinear mechanical properties...

AI Technical Summary

Problems solved by technology

However, rock deformation damage is not only affected by the randomly distributed micro-defects inside the material, but also closely related to the stress state of the rock micro-elements, so it has certain limitations.

[0004] The essence of rock deformation and failure is the whole process of internal energy dissipation and release, and energy dissipation is the internal driving force for the gradual development of rock damage. Therefore, when studying the nonlinear constitutive relationship of rock under complex stress conditions, scholars have studied Under the framework, the rock damage evolution equation is derived based on the basic principle of energy dissipation and the rock elastic damage constitutive considering energy dissipation is established. Defining damage variables from the perspective of energy dissipation can better reflect the strength weakening process of rock materials, but few Scholars apply the principle of minimum energy consumption to the establishment of the rock damage evolution equation, and the damage constitutive model established based on the energy principle seldom considers the influence of the damage threshold

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