The Study On Practical Application Of Finite Element Method In The Design Of High Arch Dam

Along with the westward exploitation putting into practice, to make use of existing natural resources, several high arch dams will be built in the southwest of China where water resource is rich. Because its complex of mechanics characteristic, shape of geometry and boundary condition, safety of the high arch dam under normal load is what engineers are concerned about.At present, stress state of arch dams is obtained by numerical analysis or model test. When stress, strain and safety of hydraulic structure such as arch dams are analyzed, because of the two methods' limits, in general, both of them are used to verify the result.The effect of complex groundsill and dam body's construction process can be considered conveniently when finite element method is used to analyze dam body's stress. But there is no design criterion correspondingly because of the stress concentration that is caused by load at dam heel and dam toe under elastic state. Furthermore, its value is easily affected by mesh size. Prof, Zhu Bofang and Prof. Fu Zuoxin present equivalent stress method, which provides an effective way for practical application of finite element method. But how to solve dam body's equivalent stress reasonably is still a problem. Finite element internal force method is presented in this paper to solve it, Based on the result of the routine method. This method utilizes the condition of internal force balance of arch system and beam system to solve their internal forces, then to solve dam body's equivalent stresses. Some examples prove that the result is stable and the value of equivalent stress is less affected by mesh size. This method provides a reliable way for application of finite element method in high arch dam's design.Usually, there are many cracks in dam body during construction period and operating period. How to simulate process of cracks' formation and development reasonably and effectively is a problem. The process can be simulated by finite element method theoretically, but reasonable result requires very small meshes. Due to limitation of computer's capacity, it is impossible to simulate cracking with routine compatible mesh- So compatible displacement method of local incompatible mesh is presented in this paper. This method can make meshes of the structure dense and meshes of the Other section sparse without affecting accuracy of result. This can decrease nod.es arid, elements of mesh efficiently.Furthermore, model test of Xiluodu's high arch dam is studied and the .result of stress and displacement is presented in this paper. This arch dam is analyzed with the method mentioned in this paper, the result and the corresponding result of the model test can be corroborated each other.