Secondary Development And Application Of Rock Water-damage Creep Model Based On FLAC^3D

Rock creep is one of important mechanical properties of rock materials,with the deepening of underground engineering,the creep effect on the stability of engineering surrounding rocks,especially soft rocks is becoming more and more important.At the same time,the water content variation of rocks will deteriorate its structure and mechanical properties,creep damage is also a product of internal fissures changes in rocks,both of them can have a non-negligible impact on the rock creep properties.However,the current research of the coupling between rock water degradation and creep damage on the constitutive relation is not perfect.In addition,several creep models in the large-scale numerical simulation software FLAC^3D?Fast Lagrangian Analysis of Continua?can neither simulate the rock acceleration creep stage nor consider the influence of water content on rock creep,which obviously can not meet the engineering requirements in creep simulation research and application of water-bearing rocks,and also affect the application scope of FLAC³DD to some extent.Therefore,based on the theory of water degradation and creep damage,the water switch and the creep damage threshold are introduced into a new creep model named rock water-damage creep model in this thesis,through which the coupling of water deterioration and creep damage is realized on constitutive relation.The main tasks and findings of the dissertation research are summarized below:The rock water-creep damage model has a good fitting effect with the triaxial compression creep test results of soft rock,and the applicability and superiority of the model in water-bearing rocks creep simulating are verified.The model parameters were inverted by LM-UGO algorithm,and it is found that the elastic modulus E₃ and viscosity coefficient?₃ of the model decrease with the increase of water content,and the coefficient?increases with the increase of water content.Afterwards,in the environment of C++language and Fish language in FLAC^3D,through deducing its constitutive equation in three-dimensional difference form,the rock water-damage creep model is secondarily developed by the interface of FLAC^3D.And the model has the same efficiency as the built-in creep models in FLAC^3D,which provides a tool for numerical simulation of water-bearing rocks considering creep damage.Finally,through the engineering simulation and analysis by rock water-damage creep model,the reliability of the model is further verified,and it is also concluded that the deformation of soft rock roadway roof,floor and the two sides increase with the increase of water content,especially the roadway two sides,which is of great guiding significance for the actual soft rock roadway support and reflects the necessity of considering the variation of water content in rock creep model...