软硬互层顺向岩质边坡失稳变形的离散元模拟

Instability Deformation Simulation of Rock Slopes with Soft-Hard Interbedded Structures based on Discrete Element Method

在工程建设中,软硬互层边坡十分常见,受岩石材料非均质性与层间软弱结构面的影响,该类边坡的变形破坏特征较为复杂,而相关研究较少。为此,该文以山软硬互层岩层结构为原型,基于离散元分析软件PFC,建立了软层裸露和硬层裸露2种模型,对软硬互层顺向岩质边坡失稳变形开展了数值模拟研究,结果表明:2种软硬互层顺向边坡失稳过程差异明显,在加速蠕变阶段时,软层裸露的边坡位移响应相比硬层裸露更为迅速,在实际工程中应当引起足够重视;在变形过程中,2种边坡内部岩层都发生了明显弯曲,而浅层滑体运动模式有所不同:软层裸露模型表现为散体沿结构面滑动,硬层裸露模型为块体折断崩落。

Soft and hard interbedded slopes are common in the hydraulic engineering.Affected by the heterogeneity of rock materials and weak interlayer structural surfaces,the deformation and failure characteristics of this type of slope are complex,but rarely studied.Therefore,this paper takes the soft and hard interbedded rock structure of Longmen Mountain in Sichuan as a prototype,and based on the discrete element analysis software PFC,two models of soft layers exposed and hard layers exposed slopes have been established.In this way,numerical simulation research was carried out on the instability and deformation of the soft and hard interbedded rock slope.The results show that:There are obvious differences in the instability process of the two models of soft-hard interbedded slopes.During the accelerated creep stage,the slope displacement response of the soft-layer exposed slope is faster than that of the hard-layer exposed slope,which should be paid attention to in actual engineering;During the whole deformation process,the inner rock formations of the two slopes are both obviously bent,but the shallow sliding body movement mode is different.The soft-layer exposed model shows an instability mode in which the loose body slides along the structural plane,while the hard-layer exposed slope shows a block collapse mode.