Construction method of power function model of two-dimensional mesoscopic time-dependent fracture of rock mass

Abstract

The invention discloses a method for establishing a rock-mass two-dimensional microcosmic season cracking power function type model. The model comprises a rock-mass microcosmic particle bond stress two-dimensional mode considering a bending moment contribution factor, a microcosmic particle bond ageing degradation degenerative two-dimensional power function type mode considering a bending moment contribution factor, a mohr-coulomb microcosmic particle season cracking criterion considering a bending moment contribution effect and provided with a stretching stop limit and a microcosmic particle linear contact two-dimensional model considering a damp effect. The method adapts to a rock mass having the stress and crack propagation velocity relation meeting the power function type and provides technical support for long-term stability prediction, evaluation and optimization design of similar deep rock mass projects in a plane state.

Description

technical field [0001] The invention relates to the technical field of engineering rock mass mesoscopic aging fracture analysis, in particular to a construction method of a rock mass two-dimensional mesoscopic aging fracture power function model. Background technique [0002] Instability and destruction of deep rock mass engineering after excavation often do not occur immediately after excavation. Generally, there are obvious deformation and rupture timeliness and hysteresis of catastrophe (rockburst, large deformation, etc.), which seriously endanger the safety of the project. Construction safety and long-term operation. At present, there are relatively few research results on time-efficiency mechanics in the mesoscopic aspect. In the article "Particle Flow Simulation of Time Effect of Fracture Expansion of Deep Buried Marble", the experiment and two-dimensional numerical analysis of the time effect of Jinping marble rupture were carried out (Journal of Rock Mechanics and ...

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Problems solved by technology

In addition, this type of model also has the following shortcomings: (1) The shear fracture criterion between particles is a horizontal line parallel to the normal stress of the parallel bond, that is, the shear rupture criterion is consistent with the normal stress state of the parallel bond Irrelevant, as long as the parallel bond shear stress is greater than or equal to the fixed parallel bond shear rupture strength, shear fracture can occur between particles, which cannot reflect that different parallel bond normal stresses in the rock mass have different parallel bond shear rupture strengths (2) The influence of the difference in bonding torque on contact failure is not considered, and the contribution of bonding torque to different lithologies is considered to be consistent; (3) For the relationship between stress and crack growth rate Rock masses that do not conform to the exponential expression, this type of model lacks adaptability

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