基于颗粒流的矽卡岩静态加载速率效应研究  

Study of Static Loading Rate Effects of Skarn Based on Particle Flow Code

作　　者：唐礼忠[1] 朱俊[1] 刘涛[1] 武建力[1] 

机构地区：[1]中南大学资源与安全工程学院,长沙410083

出　　处：《武汉理工大学学报》2013年第6期101-106,共6页Journal of Wuhan University of Technology

基　　金：国家重点基础研究发展计划(973)(2010CB732004);中南大学学位论文创新资助项目(2011ssxt270)

摘　　要：采用颗粒流离散元软件PFC2D,通过Fish语言编写程序,模拟了矽卡岩岩样3级不同加载速率下的室内单轴压缩试验,并分析了其静态加载速率效应。模拟结果表明:模拟得到的岩样破裂形态、应力-应变曲线、峰值强度变化等与试验结果较为吻合;加载速率增大,峰值强度及其对应的应变增大,且在10-2数量级内增幅明显,峰后变形能力减弱,弹性模量、泊松比基本不变;加载速率增大,临界扩容应力和扩容点对应应变增大,扩容曲线软化段都很平缓,体积膨胀急剧;岩样主要破坏形态为剪切破坏,且随着加载速率增加,由单一剪切破裂过渡到共轭剪切破裂,更易形成锥形破坏。研究结果可为相关岩体的室内试验及岩土工程的稳定性评价提供参考。In ordert to study the effect of static loading rate, the laboratory tests of skarn under unixial compression at three different loading rate were simulated, using the software of particle flow code PFC2D and program of Fish language. The results of simulation show that the rupture morphology of rock samples, stress-strain curve and peak intensity＇ s change in simulation are consistent with laboratory tests correspondingly. With the increase of loading rate, the peak strength and its corresponding strain increase, obviously especially in the range of loading rate of 10.2 m/s magnitude. The deformation capacity at post-peak decreases, but the elastic modulus, Poisson＇s ratio is substantially constant. The faster the loading rate is ,the greater the critical dilatancy stress is, and the bigger the axial strain at expansion point is. The softening stage of expansion curves is very gentle, which illustrates volume expansion rapidly. The failure mode of rock specimens are shear failure mainly, and transformed from single shear rupture to conjugate shear fracture with the increase of loading rate, so more likely to form a cone destruction.The study provides practical guides for rock mechanical tests and geotechnical stability evaluation.

关 键 词：加载速率 单轴压缩 力学特性 颗粒流法 PFC2D 数值模拟 

分 类 号：TU45[建筑科学—岩土工程]