黄土挖方边坡破坏机理及开挖方案对比分析

Comparative Analysis of Damage Mechanism and Excavation Plan for Loess Excavation Slope

为寻求安全经济的黄土边坡开挖治理方案,以黄土地区某排水管网工程为研究对象,分析挖方边坡破坏机理,并提出2种开挖治理方案;探讨了不同开挖治理方案下坡体的破坏类型、滑动模式及稳定性,并进行了方案选取。结果表明:坡体开挖后抗滑力小于下滑力,原有的平衡被打破是变形破坏的直接诱因;按方案1、2开挖后,稳定系数变为1.402、1.363,均满足要求且有一定富余;前者虽能降低整体剪切破坏风险,但后者在“固脚强腰”改善剪应力分布的同时降低了整体与局部的剪切破坏风险;后者节省了工程造价18.9%,同时也避免了“削山皮”式开挖带来的安全隐患。

In order to seek a safe and economic excavation management scheme for loess slopes,a drainage network project in a loess area is taken as the research object.Firstly,the damage mechanism of excavated slopes are explored,followed by two excavation management schemes,and finally the damage type,sliding mode and stability of slopes under different excavation management schemes are explored and the scheme selection is made.The results show that the anti-slip force of the slope is smaller than the sliding force after excavation,and the original equilibrium is broken as the direct cause of deformation damage.After excavation according to scheme one and two,the stability coefficient becomes 1.402 and 1.363,which both meet the requirements and have some surplus.Although the former can reduce the overall shear damage risk,the latter reduces the overall shear damage risk,and the latter reduces the overall and local shear damage risk while improving the shear stress distribution by"solid footing and strong waist".In addition,the latter saves 18.9%of the project cost and avoids the safety hazards associated with"clipping"type excavation.