风化岩腔边坡的演化与应力场分析

Evolution of Weathered Slope above Rock Cavity and Analysis of Its Stress Field

近水平软硬互层边坡在我国西南有广泛分布,在差异风化作用下很容易形成大量岩腔,导致凸出的岩层形成危岩体并产生大量的拉裂型崩塌灾害。人工切坡从形成到因差异风化产生岩腔,从岩腔上悬臂危岩崩塌到边坡达到最终稳定状态,反映了边坡演化的典型过程。以万州地区人工高切坡为研究对象,在分析万州地质特点的基础上,阐述了软硬互层边坡差异风化岩腔的形成过程和的形成模式,分析了高切坡悬臂危岩崩塌失稳条件和崩塌规模控制性因素,推导了悬臂拉裂型崩塌灾害的岩体失稳判据,模拟分析了岩腔形成演化过程中的应力场分布及特征,为此类边坡的工程防护治理提供了科学依据。

Flat strata and soft-hard interbedding layer slopes distribute widely in southwestern China. Large amount of rock cavity are easily occurred because of differential weathering, which results in bulge rock changes into dangerous rock body and leads to lots of tension collapse. The sequence of formation of cut slope, differential weathering caused rock cavity, cantilever rock Collapse, and final stability of slope made up the full history of typical slope evolution process. Taking the highly incised slope in Wanzhou district as research object, based on analyzing the geological characteristics of the district, the process and the mode of formation of differential weathering caused rock cavity in soft-hard interbedding layer slopes are expounded, the instability reasons of the cantilever rock and critical factors of collapse scope are analyzed, the instability criteria of cantilever tension collapse is derived, and the stress field distribution and feature of rock cavity evolution are simulated. These works can be useful for protection of such kind of slopes.