基于离散元法的岩石单轴压缩模型建立及参数校核  

Establishment of rock uniaxial compression model and parameters check based on discrete element method

作　　者：孟凡海 李玮[1] 赵欢[1] 凌鑫[1] 陈子贺 Meng Fanhai;Li Wei;Zhao Huan;Ling Xin;Chen Zihe(Petroleum Engineering College,High Efficiency Drilling and Rock Breaking Laboratory,Northeast Petroleum University,Daqing 163318,China)

机构地区：[1]东北石油大学石油工程学院高效钻井破岩国家工程实验室

出　　处：《能源与环保》2019年第8期67-72,77,共7页CHINA ENERGY AND ENVIRONMENTAL PROTECTION

基　　金：“十三五”国家科技重大专项(2016ZX05020-002)

摘　　要：建立基于离散单元法的脆性岩石单轴压缩可靠模型,通过单一变量数值模拟方法,分析4个关键参数对应力-应变曲线的影响,并较准确地模拟真实岩石的力学性能。通过仿真试验可得出结论:临界切向应力主要影响轴向压缩力-应变曲线的最大值,随着临界切向应力的减小,曲线的最大值逐渐减小;临界法向应力主要影响曲线的下降段,随着临界法向应力的减小,曲线的下降段斜率逐渐增大;切向接触刚度对曲线的3段均有影响,随着切向接触刚度的线性增加,曲线的上升段斜率逐渐增大,曲线最大值逐渐增加,下降段斜率逐渐增加;法向接触刚度主要影响曲线的最大值,随着法向接触刚度的增加曲线的最大值增加。当选取黏结参数:法向接触刚度400 MN/m^3、切向接触刚度为300 MN/m^3、临界法向应力为40 kPa、临界切向应力为20 kPa,按照这组参数标定可以较可靠地模拟出大庆三肇地区2 500~3 000 m深的岩石特性。A reliable model of uniaxial compression of brittle rock based on discrete element method was established.The influence of four key parameters on the stress-strain curve was analyzed by a single variable numerical simulation method,and the mechanical properties of real rock are simulated accurately.Through the simulation test,it could be concluded that the critical tangential stress mainly affects the maximum value of the axial compression force-strain curve.With the decrease of the critical tangential stress,the maximum value of the curve decreases gradually;the critical influence curve of the critical normal stress In the falling section,as the critical normal stress decreases,the slope of the falling section of the curve gradually increases;the tangential contact stiffness had an effect on the three sections of the curve,and the linear rise of the tangential contact stiffness increased the rising section of the curve.The slope gradually increases,the maximum value of the curve increases gradually,and the slope of the falling section gradually increases.The normal contact stiffness mainly affected the maximum value of the curve,and the maximum value of the curve increased with the increase of the normal contact stiffness.When the bonding parameters were selected:normal contact stiffness 400 MN/m^3,tangential contact stiffness was 300 MN/m^3,critical normal stress was 40 kPa,critical tangential stress was 20 kPa,and calibration was performed according to this set of parameters.It could more reliably simulate the rock characteristics of 2 500~3 000 m deep in Sanzhao area of Daqing.

关 键 词：离散元法 岩石 单轴压缩 临界切向应力 临界法向应力 切向接触刚度 法向接触刚度 

分 类 号：A142[哲学宗教—马克思主义哲学]