摘要
永久变形是评价土坝地震性能的一个重要依据。本文所分析的永久变形是由土单元在地震荷载作用下产生的永久偏应变引起的。文中根据往返荷载三轴试验结果,给出了永久偏应变的经验表达式。在确定地震作用下坝内土单元的永久偏应变时,考虑了试验土样与坝内土单元的应力状态不同的影响。采用等价结点力模型求解了坝内各结点的地震永久变形的发展过程和总量。文中用所述的方法和编写的二维有限元计算程序分析了若干个土坝的地震永久变形,给出一个简例的计算结果。
Earthquake-induced permanent deformations are important data for evaluating the behavior of earth dams during earthquakes. The permanent deformations discussed in this paper are induced by permanent deviator strain of soil elements during earthquakes. The empiric expressions for permanent strain potential are presented according to results of cyclic loading triaxial tests. Considering the difference of stress states between speciments in laboratory and elements in dams, the permanent strain potential of elements in clams is determined. The model of equivalent node forces is used to evaluate the ultimate permanent deformations and the history of permanent deformations. The computer program for two dimensional finite element analysis of permanent deformations is written according to described approach and the permanent deformations of some earth darns have been computed. For the purpose of explanation, the results of an example are presented in this paper.
出处
《地震工程与工程振动》
CSCD
北大核心
1989年第1期91-100,共10页
Earthquake Engineering and Engineering Dynamics
