Numerical analysis on mechanical difference of sandstone under in-situ stress,pore pressure preserved environment at depth  

作　　者：Hongwei Zhou Mingyuan Lu Heping Xie Wenhao Jia Ruidong Peng Yimeng Wang Bocen Chen Pengfei Jing 

机构地区：[1]School of Energy and Mining Engineering,China University of Mining and Technology-Beijing,Beijing 100083,China [2]State Key Laboratory of Coal Resources and Safe Mining,China University of Mining and Technology-Beijing,Beijing 100083,China [3]State Key Laboratory of Hydraulics and Mountain River Engineering,College of Water Resource and Hydropower,Sichuan University,Chengdu 610065,China [4]Guangdong Provincial Key Laboratory of Deep Earth Sciences and Geothermal Energy Exploitation and Utilization,Institute of Deep Earth Sciences and Green Energy,College of Civil and Transportation Engineering,Shenzhen University,Shenzhen 518060,China [5]Shenzhen Key Laboratory of Deep Underground Engineering Sciences and Green Energy,Shenzhen University,Shenzhen 518060,China [6]School of Mechanics and Civil Engineering,China University of Mining and Technology-Beijing,Beijing 100083,China

出　　处：《International Journal of Mining Science and Technology》2023年第11期1339-1350,共12页矿业科学技术学报（英文版）

基　　金：supported by the National Natural Science Foundation of China(Nos.51827901 and 52121003);the 111 Project(No.B14006);the Yueqi Outstanding Scholar Program of CUMTB(No.2017A03);the Fundamental Research Funds for the Central Universities(No.2022YJSNY13).

摘　　要：Deep in-situ rock mechanics considers the influence of the in-situ environment on mechanical properties,differentiating it from traditional rock mechanics.To investigate the effect of in-situ stress,pore pressure preserved environment on the mechanical difference of sandstone,four tests are numerically modeled by COMSOL:conventional triaxial test,conventional pore pressure test,in-situ stress restoration and reconstruction test,and in-situ pore pressure-preserved test(not yet realized in the laboratory).The in-situ stress restoration parameter is introduced to characterize the recovery effect of in-situ stress on elastic modulus and heterogeneous distribution of sandstone at different depths.A random function and nonuniform pore pressure coefficient are employed to describe the non-uniform distribution of pore pressure in the in-situ environment.Numerical results are compared with existing experimental data to validate the models and calibrate the numerical parameters.By extracting mechanical parameters from numerical cores,the stress-strain curves of the four tests under different depths,in-situ stress and pore pressure are compared.The influence of non-uniform pore pressure coefficient and depth on the peak strength of sandstone is analyzed.The results show a strong linear relationship between the in-situ stress restoration parameter and depth,effectively characterizing the enhanced effect of stress restoration and reconstruction methods on the elastic modulus of conventional cores at different depths.The in-situ pore pressurepreserved test exhibits lower peak stress and peak strain compared to the other three tests,and sandstone subjected to non-uniform pore pressure is more prone to plastic damage and failure.Moreover,the influence of non-uniform pore pressure on peak strength gradually diminished with increasing depth.

关 键 词：In-situ pore pressure-preserved ENVIRONMENT Numerical simulation approach Deep in-situ rock mechanics In-situ stress restoration and reconstruction 

分 类 号：TD313[矿业工程—矿井建设]