基于强度折减法的库岸滑坡三维有限元分析

3D finite element analysis of reservoir bank landslide based on strength reduction method

通过现场踏勘调研,根据滑坡的环境地质条件,详细探讨了该库岸滑坡的成因机制和演化过程,并重点分析了滑坡失稳的影响因素。建立滑坡体的三维有限元模型,运用有限元强度折减理论对其稳定性进行了计算分析。结果表明,滑坡体在天然状况下是稳定的,库水位上升至正常蓄水位时将超过滑坡前缘高程,滑坡安全系数降低,不满足规范规定的最小安全系数的要求,在考虑降雨入渗、库水位骤降时,滑坡进一步趋于危险;在考虑蓄水+地震工况时,库岸滑坡有失稳的可能。据此提出了削坡减载治理措施,治理后滑坡在各工况下的安全系数均满足规范的要求,研究成果对滑坡的治理具有较大的参考价值。

The genetic mechanism and evolvement process of the reservoir bank landslide were discussed detailedly based on engineering exploration and analyzing environmental geological conditions.And some main factors effecting stability of the landslide were analyzed emphatically.Through building a 3D FEM model of landslide,the stable situations of the landslide under various situations were considered based on the strength reduction method.The result shows that the landslide is steady under the natural situation.The front edge of the landslide will be drowned out when the reservoir retains water normally;the safety factor reduces and can’t meet the requirements of norms.The landslide tends to be more dangerous under rainfall infiltration and rapid drawdown of the reservoir water level.And the landslide will be instable when water storage situation and earthquake situation were considered at the same time.According to the preceding analysis,the treatment measures of cutting slope and reducing load were presented.The landslide is steady under various conditions after being controlled.The relevant conclusions and methods proposed take a good effect in landslide treatment.