摘要
土石坝是一个复杂的非线性系统,其失稳过程的力学行为是一个不可逆的非线性动力学演化过程。根据土石坝的特点,应用突变理论,建立了一个考虑坝体材料应变软化效应和水致弱化效应的尖点突变模型,通过对模型进行平衡分析,获得了坝坡失稳的力学判据。通过对失稳判据的分析得出,土石坝发生突变失稳的必要条件,取决于坝体材料特性、库水位及库水位变化情况,高洪水位或由高水位骤降时因坝坡上部材料刚度降低而容易发生突滑失稳,是坝坡稳定的控制工况。最后,根据系统突变条件得出了坝坡失稳的临界位移和临界几何—力学参数,为土石坝稳定分析和安全评价提供新的途径。
Earth-rock dam is a complex nonlinear system,its mechanical behavior when the dam slope is instable is in fact an irreversible evolution of nonlinear dynamics.In this paper,a cusp catastrophe model,which covers strain-softening effect of dam material and water-weakening effect,is constructed,based on the characteristics of earth-rock dam,applied catastrophe theory,and through the analysis of equilibrium of model,the mechanical criterion of instability of the dam slope is obtained,through the analysis of instability criterion,obtained:the necessary conditions for mutation depends on the features of the dam material and the the water level and water level changes,wenth the high flood level or by a sudden drop in the high water mark,due to the upper dam slope material stiffness reduction,dan slope prone to sudden slip instability,it's the control condition of earth-rock dam stability.Finally,according to the mutation conditions of the dam slope instability,the paper also introduces the critical displacement and the critical geometry-mechanical parameters,point out new way for embankment dam stability analysis and safety evaluation.
出处
《四川建筑科学研究》
北大核心
2011年第5期127-130,共4页
Sichuan Building Science
基金
广东省自然科学基金资助项目(07006119)
关键词
土石坝
失稳
尖点突变模型
临界条件
earth-rock dam
instability
cusp catastrophe model
critical conditions