The mesoscopic failure mechanism and the macro-mechanical characteristics of soil-rock mixture(S-RM) under external load are largely controlled by S-RM's meso-structural features. The objective of this work is to ...The mesoscopic failure mechanism and the macro-mechanical characteristics of soil-rock mixture(S-RM) under external load are largely controlled by S-RM's meso-structural features. The objective of this work is to improve the three-dimensional technology for the generation of the random meso-structural models of S-RM, for randomly generating irregular rock blocks in S-RM with different shapes, sizes, and distributions according to the characteristics of the rock blocks' size distribution. Based on the new improved technology, a software system named as R-SRM3 D for generation and visualization of S-RM is developed. Using R-SRM3 D, a three-dimensional meso-structural model of S-RM is generated and used to study the meso-mechanical behavior through a series of true-triaxial numerical tests. From the numerical tests, the following conclusions are obtained. The meso-stress field of S-RM is influenced by the distribution of the internal rock blocks, and the macro-mechanical characteristics of S-RM are anisotropic in 3D; the intermediate principal stress and the soil-rock interface properties have significant influence on the macro strength of S-RM.展开更多
基于颗粒流理论和PFC3D程序,建立Lac du Bonnet花岗岩的BPM模型,施加周期性边界条件。通过使周期性空间扭曲变形,保持恒定的平均应力p和Lode角q,进行真三轴试验,提出一种修正Mohr-Coulomb准则形状函数的新方法。建立试样的三维强度包络...基于颗粒流理论和PFC3D程序,建立Lac du Bonnet花岗岩的BPM模型,施加周期性边界条件。通过使周期性空间扭曲变形,保持恒定的平均应力p和Lode角q,进行真三轴试验,提出一种修正Mohr-Coulomb准则形状函数的新方法。建立试样的三维强度包络面,并从三轴平面、双轴平面和p平面3个角度,探讨Mohr-Coulomb准则的局限性:(1)Mohr-Coulomb准则预测的单轴抗拉强度偏大。(2)Mohr-Coulomb准则未考虑中间主应力的影响。(3)Mohr-Coulomb准则适用范围有限,在30 30s-°<q<°范围内,Mohr-Coulomb准则强度偏于保守。探索中间主应力对岩石强度的影响规律,结果表明:当2s处于低值时,1s随2s的增大而增大,而后达到了"平台期";当2s处于更高应力状态时,1s随2s的增大而减小。通过考虑中间主应力的影响,将Mohr-Coulomb准则形状函数修正为关于平均应力p的函数。将拟合的K值与修正的Lade-Duncan准则预测值进行比较,结果表明,本文的修正方法比修正的Lade-Duncan准则能更准确地描述岩石的常规三轴强度,研究方法及结论可为岩石强度研究提供有益参考,且具有一定的实际工程意义。展开更多
基金Project(51109117)supported by the National Natural Science Foundation of ChinaProject(20111081125)supported by the Independent Research Plan of Tsinghua University,ChinaProject(2013-KY-4)supported by the State Key Laboratory of Hydroscience and Engineering Project,China
文摘The mesoscopic failure mechanism and the macro-mechanical characteristics of soil-rock mixture(S-RM) under external load are largely controlled by S-RM's meso-structural features. The objective of this work is to improve the three-dimensional technology for the generation of the random meso-structural models of S-RM, for randomly generating irregular rock blocks in S-RM with different shapes, sizes, and distributions according to the characteristics of the rock blocks' size distribution. Based on the new improved technology, a software system named as R-SRM3 D for generation and visualization of S-RM is developed. Using R-SRM3 D, a three-dimensional meso-structural model of S-RM is generated and used to study the meso-mechanical behavior through a series of true-triaxial numerical tests. From the numerical tests, the following conclusions are obtained. The meso-stress field of S-RM is influenced by the distribution of the internal rock blocks, and the macro-mechanical characteristics of S-RM are anisotropic in 3D; the intermediate principal stress and the soil-rock interface properties have significant influence on the macro strength of S-RM.
文摘基于颗粒流理论和PFC3D程序,建立Lac du Bonnet花岗岩的BPM模型,施加周期性边界条件。通过使周期性空间扭曲变形,保持恒定的平均应力p和Lode角q,进行真三轴试验,提出一种修正Mohr-Coulomb准则形状函数的新方法。建立试样的三维强度包络面,并从三轴平面、双轴平面和p平面3个角度,探讨Mohr-Coulomb准则的局限性:(1)Mohr-Coulomb准则预测的单轴抗拉强度偏大。(2)Mohr-Coulomb准则未考虑中间主应力的影响。(3)Mohr-Coulomb准则适用范围有限,在30 30s-°<q<°范围内,Mohr-Coulomb准则强度偏于保守。探索中间主应力对岩石强度的影响规律,结果表明:当2s处于低值时,1s随2s的增大而增大,而后达到了"平台期";当2s处于更高应力状态时,1s随2s的增大而减小。通过考虑中间主应力的影响,将Mohr-Coulomb准则形状函数修正为关于平均应力p的函数。将拟合的K值与修正的Lade-Duncan准则预测值进行比较,结果表明,本文的修正方法比修正的Lade-Duncan准则能更准确地描述岩石的常规三轴强度,研究方法及结论可为岩石强度研究提供有益参考,且具有一定的实际工程意义。