基于突变理论的重力坝沿建基面失稳判据研究

Study on Criterion of Gravity Dam Instability along Foundation Plane Using Catastrophe Theory

突变理论注重研究系统状态发生突变时外界的控制条件,主要阐述非线性系统如何从连续渐变状态向系统性质突变的转变。混凝土重力坝不仅材料本身非线性明显,并且系统也具有较强非线性特性。基于突变理论,研究了突变理论应用于重力坝系统抗滑失稳的可行性,并分别从能量突变、位移突变以及塑性屈服区面积突变进行了重力坝沿建基面的失稳判据研究。通过分析计算结果并将其与传统分析方法比较后指出,对于不同出发点的突变判据,所得到的结果并不一定一致。为了更好的表征结构的性态的转变,应当选择合适的突变指标,以客观反映系统的状态变化,比如本文中的总塑性应变能指标。同时失稳判据的确定不能仅依赖于一种方法,应该建立一种综合评价的方法体系。

The catastrophe theory was used in the study of outside control conditions when the catastrophe happens to the system,and it mainly expatiates on how the nonlinear system tends toward catastrophe change of the system state.The material of concrete gravity dam itself is not linear,and the structure system is highly nonlinear.Using the catastrophe theory and combining the energy as well as displacement and area of plastic zone methods,the feasibility of the criterion of gravity dam instability along the foundation plane was studied.After analyzed the simulation results and compared with the traditional method,it points out that through different points of views,the results will not necessarily match.For better representing the state of the system,the chosen index should be objective,as the total plastic energy method was used.To determine of instability criterion should not based on only one method,it is suggested that a comprehensive evaluation system should be developed.