贵州软硬互层地质条件下典型崩塌稳定性分析

Stability Analysis of Typical Collapse under the Geological Condition of Soft and Hard Rock Interbedded in Guizhou Province

以贵州省赤水市立树天崩塌为例,基于野外地质灾害详细调查,总结崩塌的形成因素及失稳模式,通过FLAC3D软件建立软硬岩互层条件下的三维地质数值模型,以此分析崩塌的稳定性,结果表明:立树天崩塌的形成与斜坡岩性组合、危岩体结构面及气象条件有关,其失稳模式包括差异风化阶段、岩体破坏阶段与岩体失稳崩落阶段;泥岩空腔附近出现拉应力与压应力集中区,使陡崖岩体处于不稳定状态;综合分析得出崩塌更容易发生在上部陡崖,而下部陡崖主要发生局部剪切破坏,这可为该地区类似崩塌的防护治理提供经验。

Taking the collapse of the Lishutian of Chishui city in Guizhou Province as an example,based on the detailed investigation of geological hazards,this paper summarizes the relevant factors of collapse formation and its instability model,and constructs a three dimensional geology numerical model under the condition of soft and hard rocks interbedding by using FLAC3D software,so as to analyze the stability problems of collapse.Results show that:the formation of the collapse is related to the lithological combination of the slope,the structural plane of the dangerous rock mass and meteorological conditions,and its instability mode generally includes di-fferential weathering stage,rock mass failure stage and rock mass instability and collapse stage;the tension stress and pressure stress concentration area appear near the mudstone cavity,which is disadvantageous to the stability of the cliff rock mass structure;the comprehensive analysis shows that the collapse is more likely to occur on the upper cliff,while the local shear failure mainly occurs on the lower cliff,which can provide experience for the protection and control of similar collapses in this area.