The Research On Mechanism Of Rock Creep–Seepage Coupling

Rock structure is a non-continuous and non-homogeneous body, whose mechanical properties are nonlinear, anisotropic and rheological properties change with time. Water is an important factor that affects the nature of creep rupture in failure. As time increases, led to the occurrence of major rock projects, cause casualties and significant economic losses, and So to carry out creep rupture and flow coupling rules for long-term stability of rock engineering has great theoretical and practical application value. Based on the previous studies,researchs on the triaxial creep experiment, the finite element theory and numerical simulation of coal and rock, the comprehensive analysis of the rock engineering of instability and failure phenomenon, the main work is as follows:(1) Coal (rock) samples were carried out triaxial creep test and creep– seepage coupling test, what obtain the long-term strength of carbonaceous mudstone , the different moisture content of coal's (rock) effect on creep properties of specimens, determined parameters of the creep model and when confining pressure,loading and unloading, and constant pressure the changes of permeability and the coal (rock) sample creep law on permeability. For different rock and confining pressure, pore pressure conditions, permeability through the process of creep test, we can get a fitting about the corresponding penetration– creep curve and equation.(2) Based on elastic finite element analysis, introduce constitutive equation of viscoelastic and viscoplastic, and combine the elasticity and plasticity of the equilibrium differential equation, geometric equations and boundary conditions, establish rheological equations. concerned.by application of maximum tensile stress theory, establishes the tracing method of maximum tensile stress and simulates unit process of rheological deformation, cracks initiation, expansion and gathering, and establishes a judgment criterion for the creep rupture.(3) Based on mixture theory and according to the equivalent continuum model and the rheological basic theory, we can establish the rheological model that under the effect of coal (rock) body stress field and seepage coupling, to derive the corresponding equations of the overall direct coupling .Given coal (rock) body of stress coupled with the seepage flow under the action of the finite element analysis format, and we conduct the finite element program's design and establishment.(4) Based on rheological experiment and the finite element theory on the couple between the creep and seepage flow, two models which were respectively the creep rupture and the couple between creep and seepage were proposed by the FEPG Software Platform, further the two models were applied to investigate the long-term stability of stratified slope. In terms of the rupture of the creep and the abscission layer creep under the normal force loading, stress variation with the time evolution and the displacement variation in different directions on the monitoring points were analyzed by the creep rupture model. Meanwhile by the model of the couple between creep and seepage, water hydraulic variation both with the time and the displacement were conducted.