针对软土地区的桥梁常因软土蠕变而产生病害的问题,研究了土体蠕变特性对桥台软基变形分析的影响。首先引入改进的西原模型;然后将桥台及软基简化为可共同考虑土体蠕变的桩-土-桥台共同工作的有限元计算模型,基于蠕变计算的时步-粘性初应变法,给出可考虑软土蠕变非线性特性的有限元计算方法,并据此编制出相应的有限元计算程序;最后利用该程序对某桥台桩基工程实例进行分析,得到了该桩基桥台后软土蠕变场等值线图,反映出桥台与桩对蠕变场的影响范围及承台与桩交接处的应变集中现象。
Based on the problem that bridges sited in soft clay area are frequently damaged by creep of soft subsoil, authors analyzed deformation of soft subsoil behind bridge abutment considering creep property. Therefore, revised Xiyuan model was introduced firstly. Then, bridge abutment and soft subsoil were transformed into FEM calculation model. Based on time step-viscous initial strain method, a FEM method which could take nonlinear creep property of soft clay into account was established, and relevant FEM program was designed. At last, an example was analyzed by the FEM program, and strain contour charts of soft subsoil behind pile foundation were got, which showed the influence area of pile and abutment, and strain concentration at joint of abutment and piles.