Numerical Simulation Of Cracking For Arch Dam Under Water Pressure

Arch dam plays an important part in the modern water conservancy and hydropower project construction. It has reasonable force, high bearing capacity, and low cost Etc, more and more engineers to choose this kind of dam type. In the construction process, arch dam structure generated certain stress due to concrete temperature change, resulting in deformation, and stepwise cracking. In the hydraulic structure operation period, also because of natural conditions, such as changes in surrounding temperature and humidity, resulting in concrete structure cracks. In short, the performance of concrete material itself determines arch dam structure more or less have crack defect. Therefore, to study the cracking of arch dam structure is very important. This paper has been carried out from the following aspects:(1) This paper summarizes the development of arch dam in home and abroad in recent years. In recent years the dam type develops toward high and thin type, traditional arch dam design criterion can’t fully meet the safety requirements. Therefore, through the computer numerical analysis method to study the arch dam cracking. Introduces several numerical methods commonly used to research the cracks of arch dam, this paper adopts the extended finite element method for research.(2) Introduces the related knowledge of fracture mechanics. Include the origin and development of fracture mechanics, the important parameters in fracture mechanics, and the fracture criterion. Practical engineering often in three-dimensional crack state, the maximum axial tensile stress criterion was used as the fracture criterion of arch dam cracking.(3) Using CATIA software set up the geometric model. CATIA has strong curve, curved surface function, using the curve function, multiple section commands perfectly established3D double-curvature arch dam-foundation system model, for behind cracking analysis can be carried out smoothly.(4) To achieve cracking based on ABAQUS platform. Cracking is a highly nonlinear problem, there is high demand for the model and solving. ABAQUS has strong ability for nonlinear analysis, this paper illustrate the accurate calculation through stress balance and calculation of stress intensity factor. To use the extended finite element method in ABAQUS achieves the expansion of cracks under water pressure. (5) Use the established model of SHA Lao-He arch dam to analysis the stress, and the results show:Under water pressure the arch dam stress properties changed, stress is not very well transmit to the dam abutment, but more focused on the dam body, especially around the crack and surrounding area of the dam. The stress analysis was carried out for vertical crack on left and right dam. Results show that, the left dam stress is ideal, even if the crack occur it is slightly extended, but the right dam crack easily extended; In the vertical crack depth is less than0.5meters, length is less than2meters, the dam is safe; when the horizontal crack depth reaches3meters, length reached15meters, the dam is in danger, should take appropriate remedial measures.