充填体和围岩-充填体界面剪切特性对比试验研究  

Comparative experimental study on the shear behavior of cemented paste backfill and surrounding rock-backfill interface

作　　者：修占国 王述红[1] 王斐笠 任凤玉[1] NGUYEN Vantuan XIU Zhanguo;WANG Shuhong;WANG Feili;REN Fengyu;NGUYEN Vantuan(School of Resource and Civil Engineering,Northeastern University,Shenyang,Liaoning 110819,China)

机构地区：[1]东北大学资源与土木工程学院,辽宁沈阳110819

出　　处：《岩石力学与工程学报》2021年第8期1628-1642,共15页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家自然科学基金资助项目(U1602232);国家重点研发计划(2016YFC0801601);辽宁省重点科技计划项目(2019JH2-10100035)。

摘　　要：拱效应理论模型在剪切力学参数(黏聚力c和内摩擦角j)的选取上采用了等效原则。为了区分剪切参数的选取对拱效应理论模型的影响,首先,采用三轴测试方法,开展常侧向约束条件下围岩-充填体界面的三轴剪切和充填体的三轴压缩试验。基于Mohr-Coulomb强度理论框架,对不同养护时间下充填体和围岩-充填体界面的剪切力学参数进行对比和量化分析。然后,利用电子扫描电镜(SEM)和热差异分析(TG/DTG)的分析手段,充分解释充填体和围岩-充填体界面剪切参数的差异性。最后,依据试验测试结果,对Terzaghi理论模型的工程应用进行讨论。研究表明,随侧向约束的增加,围岩-充填体界面的剪切位移-剪切应力曲线呈现出多峰值现象,且充填体的轴向应变-偏应力曲线呈现出明显的弹性强化阶段。充填体的剪切力学参数(c_(b),φ_(b))要明显大于相应围岩-充填体界面的参数(c_(i),φ_(i))。两者的黏聚力比值(c_(b)/c_(i))相差了2.26~2.67倍,内摩擦角比值(φ_(b)/φ_(i))相差了1.65~2.76倍。且采用围岩-充填体界面的剪切参数(c_(i),φ_(i))进行充填采场竖向应力(σ_(v))的预估能有效地克服Terzaghi理论模型的局限性。研究结论可为充填采场拱效应的预估和数值分析中力学参数的选取提供一定的参考。The equivalent method of shear mechanical parameters(cohesion c and internal friction angleφ)is used in the arching theoretical model.To investigate the influences of different shear mechanical parameters on the arching theoretical model,the triaxial tests under constant confining pressures were firstly carried out to study the shear behaviors of the surrounding rock-CPB(cemented paste backfill)interface and the triaxial compression behaviors of the CPB.Based on the framework of Mohr-Coulomb strength theory,the shear mechanical parameters of the CPB and the surrounding rock-CPB interface were compared and analyzed under different curing times.Then,The scanning electron microscopy(SEM)and the thermal differential analysis(TG/DTG)methods were used to explain the difference in the shear behaviors of the CPB and the surrounding rock-CPB interface.Finally,based on the experimental results,the engineering application of Terzaghi's theoretical model was also discussed.The results show that with increasing the confining pressure,the shear displacement-shear stress curves of the surrounding rock-CPB interface present a multi-peak phenomenon and the axial strain-deviatoric stress curves of the CPB show an obvious elastic strengthening stage.The shear mechanical parameters(c_(b)andφ_(b))of the CPB are significantly larger than the corresponding parameters(c_(i)andφ_(i))of the corresponding surrounding rock-CPB interface.The ratio of the cohesion(c_(b)/φ_(i))between the two types(CPB and surrounding rock-CPB interface)is 2.26 to 2.67 times,and 1.65 to 2.76 times for the corresponding ratio of the internal friction angle(φ_(b)/φ_(i)).Moreover,using the shear parameters(c_(i),φ_(i))of the surrounding rock-CPB interface to predict the vertical stress(σ_(v))inside the CPB structure can effectively overcome the limitations of the Terzaghi's theoretical model.The conclusions can provide a reference for the prediction of the arching effect of the CPB structure and the selection of mechanical parameters in the numerical anal

关 键 词：采矿工程 膏体充填体 围岩-充填体界面 三轴试验 剪切力学参数 Terzaghi理论模型 

分 类 号：TD32[矿业工程—矿井建设]