贵州上洋水河流域拉裂-倾倒型崩塌机理研究

MECHNISIM OF ROCKFALL WITH CROCK-TOPPLING MODE AT UPSTREAM OF YANGSHUI RIVER BASIN IN GUEZHOU PROVINCE

贵州上洋水河流域采矿工作引发了形式多样、成因复杂的崩塌地质灾害。以拉裂—倾倒式崩塌失稳模式为例,在分析斜坡结构特征的基础上,运用岩体力学理论对崩塌形成岩体的受力演化过程以及中间出现的压缩、挤胀等现象进行了深入研究,并采用离散元数值模拟再现了崩塌形成的变形破坏过程。研究结果表明:磷矿开采产生采空区引起斜坡的应力应变调整,使得岩体产生变形,出现挤胀扩容现象导致岩体失稳倾倒,继而引发崩塌。岩体受力变形过程分为应力调整结构面张拉贯通-岩体变形受压-坡脚岩体挤胀扩容-岩体失稳破坏等4个阶段。在这整个过程中,应力应变的调整和岩体的变形形态以及裂隙的张拉形成相互作用,共同影响着崩塌的进行。

Many kinds of complex rockfall geological disasters are induced by the mining at the upstream side of the Yangshui river basin in Guizhou province.The cracking-topple model of failure is taken as an example in this article.Based on the analysis of slope structure,the process of the rockfall developing is studied.It includes the exerted force,the compression and the dilatancy in rock mass.During the study,the spacing-stress-analysis theory of rock mechanics is used.The DEM simulation is used to verifying the deformation behavior and failure mode. The conclusion can be drawn as follow.The rockfall is triggered by the Phosphate mining.Then the stress-strain adjustment and deformation of the rock mass are caused so that the rock mass dilatancy leads to instability of rock dumping,and then cause collapse.The process of load and deformation can be divided into four phases as follows. The discontinuities are stretched and cut through.The compressed rock mass deformed.The rock mass gets dilatancy. And the rock mass gets failure.The adjustments of the stress and strain,the deformation and the cracks influence each other.