岩石类材料的微缺陷主要有微裂纹和微孔洞,当压力水渗透到微裂纹中时,可在微裂纹上产生附加张开应力.利用叠加原理,对计及微裂纹内水压力的岩石类材料在三轴压缩应力下的响应特性进行分解.考虑无限大体深埋椭圆形裂纹在远场三维压缩应力下的变形、扩展和偏折,得到代表性单元中任意空间取向的单个闭合椭圆形微裂纹及其偏折微裂纹引起的附加柔度张量.假设三轴压缩下,代表性单元渗透特性变化主要取决于偏折微裂纹扩展所引起的法向开度变化,结合达西定律和立方定理,推导出单个偏折微裂纹的附加渗透张量表达式.采用Taylor方法考虑微裂纹系统对代表性单元变形和渗透性影响,利用概率密度函数得到三轴压缩下岩石类材料的三维细观损伤-渗流耦合本构模型.数值计算表明采用本模型的计算结果与试验结果吻合较好.%Microcracks and microvoids are the main microdefects in rock-like materials. When water infiltrates into microcracks,an additional opening stress will be caused on the surface of microcrack. Based on superposition principle,the response characteristics of these rock-like materials which need to consider the water pressure in microcracks under triaxial compression are separated. Considering the deformation,extension and kink of elliptical microcracks in infinite deep buried rock under the condition far field 3D compressive stress,the additional flexibility tensor caused by single closure elliptical microcracks and kink microcracks on any space orientation in a RVE(representative volume element) is obtained. With the assumption that the permeability of the RVE is mainly up to the variation of kink microcrack extension on normal direction under triaxial compression,and making use of the Darcy's law and cubic law of laminar flow,the expression of additional permeability tensor of single kink microcrack is derived. Considering the effect of microcrack system on the deformation and permeability of RVE by Taylor's scheme,a 3D meso-mechanical coupling constitutive model of damage and permeability in rock-like materials under triaxial compression is obtained by probability density function. The numerical calculation shows that the calculations of this model agrees well with that of test.
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