碎石土古滑坡稳定性分析

STABILITY ANALYSIS OF ANCIENT DEBRIS LANDSLIDE

为准确评价碎石土古滑坡稳定性,通过资料的搜集整理和分析、现场工程地质调查与勘探以及室内外的物理力学试验,采用三维大变形弹塑性接触有限元算法、数理统计分析法和不平衡推力法,结合柘州岭碎石土古滑坡工程实例,运用碎石土边坡地下水管网状排泄系统理论,分析降雨作用下碎石土古滑坡的复活解体破坏过程,计算和分析该类型滑坡稳定性。同时,结合其他工程实例,对弹塑性接触有限元算法在碎石土滑坡稳定性分析中的适用性进行研究。研究结果表明:采用考虑降雨作用的大变形弹塑性接触有限元算法可以考虑滑坡体的空间效应,较好地反映碎石土古滑坡在降雨作用下所处的实际状态及其复活破坏过程;对于浅层、中深层碎石土滑坡和复活碎石土古滑坡,分别采用二维、三维小变形和三维大变形弹塑性接触有限元算法分析相应类型滑坡的稳定性,可以得到符合实际、令人满意的计算结果。

In order to accurately evaluate the stability of ancient debris landslide,through the collection,arrangement and analysis of related data,the site investigation and exploration of engineering geology,indoor and outdoor physico-mechanical tests,adopting the analytic means of mathematic statistics,unbalanced-thrust method and three-dimensional large deformation contact elastoplastic finite element algorithm,and the theory of groundwater pipe network drainage system,connected with the engineering concrete example of Zhezhouling revived ancient debris landslide in Zhejiang Province,its process of the reviving and failure under rainfall was analyzed.Furthermore,this landslide stability was analyzed and computed also.Meanwhile,with other engineering concrete examples,the applicability of contact elastoplastic finite element algorithm used to analyze the debris landslide stability was studied.The research results show that to analyze the stability of ancient debris landslide by the three-dimensional large deformation elastoplastic finite element contact algorithm may consider the spatial effect of landslide mass,which makes computation result still be more accurate.Secondly,adopting the three-dimensional large deformation contact elastoplastic finite element algorithm with the action of rainfall may better reflect the actual locating state and sliding process of ancient debris landslide under the action of rainfall;and it may afford one method that can be used as a reference to the stability analysis,accurate evaluation and forecast of this type of landslide.Additionally,for shallow debris landslide,medium and deep one,and ancient one,two-dimensional and three-dimensional small deformation contact elastoplastic finit element algorithm and three-dimensional large deformation one were separately adopted to analyze the stability of corresponding debris landslide,in which the satisfactory computation result according with the reality can be achieved.