大坝/地基系统应力-应变分析的不连续有限元法

根据虚功原理,提出大坝/地基系统应力-应变分析的不连续有限元法。该方法将大坝和地基分成2个子域,它们之间的网格相互独立,通过建基面变形与两侧大坝、地基单元位移的几何相容方程、建基面的本构方程和系统整体的平衡方程来实现不连续网格的耦合。运用该方法分析一个复杂地基上的重力坝算例,并与常规有限元法的计算结果进行对比,验证所提分析方法的正确性。由于大坝和地基的网格相互独立,因而网格剖分工作相对简单且可以并行完成,特别适合于复杂地质条件下的大坝变形和稳定分析。

DISCONTINUOUS FINITE ELEMENT METHOD FOR STRESS-STRAIN ANALYSIS OF DAM/FOUNDATION SYSTEM

According to the virtual work principle，a 3D discontinuous finite element method for the stress-strain analysis of dam/foundation system is presented. In this method，the complex domain for the whole system can be divided into two unconcerned subdomains：the subdomain of dam and the subdomain of foundation，the grids between which are mutually dependent. The discontinuous grids are coupled by using the geometric compatibility equations for the foundation surface deformation and element displacements of foundation and two sides of dam，the constitutive equations of foundation surface and the equilibrium equations of the whole system. An example of gravity dam on complicated foundation is studied by this method. The study results are in accordance with those from the general finite element method；and the precision and validity of this method is proved. Because the meshes of dam and foundation are independent from each other，the preprocessing of the proposed method is relatively simple and even the grids can be generated parallelly. The method can be widely used in the deformation and stability analysis of dams under complicated geological conditions.