极弱胶结岩体再生结构的形成机制与力学特性试验研究

极弱胶结岩体中黏土矿物成分含量较高,胶结程度较差,胶结物为泥质胶结,对水敏感,可塑性强;基于土体固结与杠杆加载原理,自主研制了极弱胶结岩体再生结构形成试验装置,确定了再生结构岩样分级加载与固结稳定方法,形成了不同含水率极弱胶结岩体再生结构岩样,揭示了极弱胶结岩体再生结构的形成条件与形成过程。开展了不同含水率再生结构岩样的单轴与三轴压缩试验,揭示了再生结构岩样的变形及强度参数与应力状态、含水率变化的演化规律。分析了极弱胶结岩体再生结构岩样的全应力-应变曲线特性,揭示了其体积应变的演化规律;通过对极弱胶结岩体再生结构岩样单轴与三轴压缩试验破坏模式的分析,反映出极弱胶结岩体再生结构岩样的破坏模式受含水率影响较大。

Experimental study on formation mechanism and mechanical properties of regenerated structure of very weak cemented rock mass

Clay minerals in very weak cemented rock mass are often high in content.Due to the argillaceous cementation,the cementation of this rock is poor and sensitive to water,and has strong plasticity.Based on the principle of soil consolidation and lever loading,an experimental device for regenerative structure formation of very weakly cemented rock mass was developed independently,and the method of graded loading and consolidation stabilization was determined.At the same time,the rock samples of regenerated structure rock mass with very weakly cementation at different moisture ratios were formed,and its formation condition and process was revealed.Uniaxial and triaxial compression tests were performed on the rock samples with different moisture ratios,the deformation laws of the rock samples,and the relationships between strength parameters and stress state and moisture ratio were revealed.The total stress-strain curve characteristics of the structural rock samples were analyzed,and the evolution law of volumetric strain was revealed.By analyzing the failure modes of uniaxial and triaxial compression tests of the rock samples,it was found that the failure modes of the rock samples are greatly affected by moisture ratio of cementation.