基于卸荷岩体力学的大岗山坝肩边坡水平位移发育的多因素影响分析

Multiple factors analysis of influence of developing horizontal displacement at Dagangshan dam abutment slope based on unloading rock mass mechanics

在现阶段工程运用中,卸荷岩体力学理论中还需完善和扩充的几个方面为①锚索施加前后卸荷效应对边坡水平位移的影响;②超前开挖锚固滞后的方案会对具体工程岩体水平位移产生的影响;③关键工程结构面连通率对卸荷岩体位移的影响;④地震作用下卸荷岩体的水平位移响应;⑤地震作用下不同连通率对水平向位移的影响。针对此,以大岗山坝肩边坡为对象展开研究。分析指出岩体开挖卸荷后回弹变形和压缩变形都会大于未考虑岩质劣化时的计算变形。同时指出,卸荷条件下两种施工方案对坡面的水平向位移造成的影响较小,为超挖多级而锚固措施相对滞后的现场施工过程的可行性提供依据。统计出各剖面在不同高程水平位移随地震加速度发展特征,建议水平位移随地震加速度呈非线性变化区域为防震抗震重点加固区域。研究发现,连通率的增大会导致卸荷裂隙XL9-15,XL316-1的塑性区发育明显增大,而裂隙范围内塑性区的加剧不会明显地反映在坡面关键点的变化上,开挖工况可能造成表观位移较小的突发性崩塌。

At present,in engineering application,there are something to improve and extended in unloading rock mass mechanics theory.First,unloading has effect on horizontal displacement of slope before and after anchor is applied;second,overbreak and anchor lag have effect on horizontal displacement of rock in the concrete engineering.Third,the connectivity rate of structural plane has effect on displacement of unloading rock;fourth,unloading rock has horizontal displacement response under earthquake action.Fifth,different connectivity rates have effect on horizontal displacement under earthquake action.So,based on unloading rock mass the theory,it carries out the research of Dagangshan dam abutment slope developing horizontal displacement.Adopting construction.It carries out the research of Dagangshan dam abutment slope.Pointed out that rebound deformation and compression deformation after the rock excavation unloading will be greater than does not take into account when calculating the deformation of the rock deterioration.Statistics of profiles of the horizontal displacement the characteristics with the development of the earthquake acceleration at different elevations,the proposed horizontal displacement with changes in earthquake acceleration was nonlinear region the focus of aseismic and reinforcement for the earthquake region it is.Indicated that the two types of program under unloading condition engender the smaller impact to the slope horizontal displacement,multi-stage overbreak,anchoring measures is lagging behind the scene of the feasibility of the construction process to provide a basis.The research shows that increase of connectivity rate will cause that plastic zone of unloading fissure XL9-15,XL316-1 increase obviously,but within fissures extension the increase of plastic zone is obviously not the key point reflected in the changes in slope,and the excavation work could cause the apparent smaller displacement of the status of the sudden collapse.