针对红层软岩遇水软化问题,在已开展的粉砂质泥岩饱水软化试验结果的基础上,从建立软岩微观结构模型出发,定量化研究软岩软化的力学机制。首先将描述粉砂质颗粒特性的结构元件引入到M.Tuller、D.Or提出的黏土矿物微结构模型中,提出了软岩微观结构组合元件;然后结合软岩饱水软化试验中微观结构测试结果,考虑天然状态软岩微观结构的基本类型特征,建立了描述粒状结构与致密条块状结构软岩的两类典型微观结构单元;在此基础上,采用重整化群方法,分别建立了两类软岩软化的重整化模型,并基于重整化原理,分析了软岩软化过程微观结构演化的临界判据,搭建了软岩微观结构与其力学特性之间的定量关系。通过对比软岩饱水软化过程力学性质试验结果,验证了所建立模型的合理性,为进一步开展软岩软化全过程定量化研究奠定基础。
Aiming at the softening problem of red-layer soft rock,the quantified study of softening mechanism has been carried out from the point of microstructure evolution,based on data from the saturated softening test of sandy mudstone.Firstly,a structure component describing the granular characteristic is proposed to combine with the microstructure model of clay mineral proposed by M.Tuller,D.Or,and the combination components of microstructure for soft rocks are obtained.Then considering the basic types and features of soft rock microstructure,two typical microstructure units to represent the granular structure and dense stripy structure are established.On this basis,renormalization group method is adopted to build the renormalization model and analyze the critical criterion for microstructure evolution of soft rocks in softening process.So the quantified relationship between microstructure and mechanical properties is obtained.Finally,according to comparing the results of the mechanical properties test of saturated soft rocks,the rationality of proposed models is verified.