FLAC3D应变软化与摩尔库伦模型工程应用对比

Engineering application comparison of strain softening model and Mohr-Columb model in FLAC3D

为探索能合理反映围岩应变软化特征的数值分析方法,设计了2组单轴数值实验,对摩尔库伦模型与应变软化模型进行对比分析,以得到不同本构条件下岩石的应力应变规律的差异;选取小官庄铁矿一段深埋巷道进行了数值模拟,分析了围岩在不同本构下的位移、塑性区的分布规律;基于FLAC3D内嵌的fish语言,编制了计算围岩点安全系数的程序,对不同本构模型下围岩的稳定性进行了评价。分析结果表明:应变软化模型得到的围岩竖向与水平位移均大于摩尔库伦模型下的对应结果,塑性区向直墙两侧与拱顶扩展更深。应变软化模型计算得到的围岩不稳定区域增大,表明巷道开挖对围岩扰动范围更大。应变软化模型的结果更接近于工程实际,更合适反映深埋工程的应力变形特性。

To evaluate surrounding rock strain-softening phenomena accurately,a series of rock uniaxial numerical loading experiments were preceded,and the stress-strain numerical results of mohr-coulomb elastoplastic and strain-softening models were analyzed.Based on the strain-softening and Mohr-Coulomb models,the deep underground Xiaoguanzhuang tunnel surrounding rock deformation,plastic zone,safety factor and rock stability were investigated.Based on the FLAC3Din-line fish language,the safety factor program was compiled.The simulation result indicated that,compared with Mohr-Coulomb elastoplastic model,strain-softening model surrounding rock displacement were larger,and plastic zones extended deeper.In strain-softening model,the unstable region was larger,which indicated excavation would cause a larger range of disturbed area.Strain-softening model numerical results were closer to the actual results.Strain-softening model can reflect deep engineering stress strain characteristics very well.