溶蚀岩体具有明显的多相复合性质,其细观溶蚀孔隙与微裂纹会对岩体宏观力学特性产生显著影响,而针对孔隙结构特征对溶蚀岩体力学影响的研究并不多见.首先基于岩体溶蚀损伤演化机制研究的文献资料,将溶蚀岩体孔隙结构分为虫洞型与蜂窝型,采用颗粒流模拟手段,建立具有不同孔隙结构特征的溶蚀岩体的颗粒流模型;从细观力学角度分析孔隙结构特征及其发育程度对岩体力学行为特性的影响;分析孔隙结构特征对溶蚀岩体受载损伤演化、岩体破坏模式及破坏机理的影响.数值模拟结果表明,溶蚀岩体孔隙结构特征对岩体力学行为特性存在较大影响.对于具有不同孔隙结构特征的溶蚀岩体而言,其力学特性对岩溶发育程度的敏感性不同.实际工程中仅以孔隙率这一宏观等效指标来评价溶蚀岩体并不完善,应进一步考虑孔隙结构特征对岩体受载过程中力学特性的影响.
Pores and micro-cracks,which are distributed among dissolution rock mass,have great effects on mechanical characteristics via damage evolution.However,meso-mechanism during damage evolution in dissolution rock is still fuzzy thus far.First,pore structures in dissolution rock were classified into two categories:wormhole type and honeycomb type,and the numerical models with different pore structure characteristics were built based on particle flow code.Then,an effort was made to study the influences of pore structure characteristics and pore development degree on rock mechanical behavior characteristics.Furthermore,rock failure mode and failure mechanism were analyzed under different pore structure characteristics.Numerical simulation results show that pore structure characteristics have great effects on rock mechanical behavior characteristics,and mechanical characteristics of dissolution rocks with different pore structure characteristics shows different sensitivity.In practice,it is not enough to evaluate dissolution rocks by porosity alone and pore structure characteristics should also be taken into consideration for it has a profound impact on the mechanical characteristics of dissolution rock in loading process.