开挖条件对不同基覆界面滑坡堆积体稳定性影响

Effect of Excavation Conditions on the Stability of Landslide Deposits with Different Deposit-Bedrock Interfaces

目的 研究开挖条件对不同基覆界面形态滑坡堆积体稳定性影响,为滑坡堆积体大规模开挖方案提供参考。方法 利用有限元分析软件ABAQUS对类直线形和椅形基覆界面滑坡堆积体进行数值模拟,分析开挖前后的滑坡体变形特征;随后通过模拟正交试验分析开挖参数对滑坡堆积体稳定性影响规律,最终得出最优开挖方案。结果 类直线形基覆界面滑坡堆积体最优开挖组合是开挖点至坡脚水平距离150 m、开挖建筑平台宽度20 m、开挖角度110°、相邻开挖平台垂直高度7.5 m;椅形基覆界面滑坡堆积体的最优开挖方案是开挖点至坡脚水平距离250 m、开挖建筑平台宽度25 m、开挖角度130°、相邻开挖平台垂直高度15 m。结论 基覆界面形态对开挖方案的选取及边坡稳定性影响显著,类直线形基覆界面宜选取在滑坡体中部开挖,而椅形基覆界面宜选取在滑坡体后缘开挖。

Investigating the effect of excavation conditions on the stability of landslide deposits with different forms of deposit-bedrock interface,and providing references for large-scale excavation of landslide deposits.ABAQUS software was used to carry out numerical simulations of landslide deposits at the quasi-linear and chair-like deposit-bedrock interfaces.First,the deformation characteristics of landslide deposits before and after excavation,as well as the impact of excavation on the safety and stability of landslide deposits were analyzed.Secondly,the influence law of excavation on the stability of landslide deposits was analyzed via an orthogonal test.Finally,the optimal excavation scheme was obtained.The optimal excavation combination of landslide accumulation at the interface of quasi-linear linear foundation and cover is 150 m in excavation position,20 m in width of excavation building platform,110°in excavation angle,and 7.5 m in vertical height of adjacent excavation platform.The optimal excavation scheme for the landslide accumulation at the interface of the chair foundation is 250 m.The optimal width of the excavation building platform is 25 m,the excavation angle is 130°,and the vertical height of the adjacent excavation platform is 15 m.The morphology of the deposit-bedrock interfaces significantly affects the excavation plan and the stability of the landslide deposits.It is preferable to excavate in the middle of the landslide deposits at the quasi-linear base-bedrock interface,while it is preferable to excavate in the back edge of the landslide deposits at the chair-shaped base-bedrock interface.