Analysis Of Gravity Dam Stability Against Deep-sliding

Gravity dam maintains stable on its own weight, so, safety is the most fundamental and most important requirements of gravity dam design. Usually, the basement of dam is rarely complete, and often there are complex arid joints, fractures or faults geological structure, thus some unpredictable sliding channel forms. Because it is hard to find or to clearly understand the geological defects of the dam foundation, some serious engineering accident often happens.Therefore, research on the deep anti-sliding stability of gravity dam in engineering is universal and urgent. Some rock masses of dam foundation exist engineering geological defects such as faults, joint, cranny and weak layers. So it is of great significance to apply stability analysis and evaluation and put forward reasonable measures on the dam practice, which is also technical and economic.At present, there are many methods in the stability analysis of gravity dam, but in practical projects, the usual method is a combination of finite element method with rigid body limit equilibrium method.Its advantage is as followed:it can avoid the difficulty bringing in the influence factors of rigid body limit equilibrium method, and regulate the definition of safety factors which gives a convenience for designers to use.In this paper the author put forward that the finite element limit equilibrium method created and developed by professor Shao longtan is better than the rigid body limit equilibrium method and finite element strength reduction method through the theoretical analysis and example calculation comparison. Finite element limit equilibrium method theory is rigorous, fully reliable in computing and verification. It assembles respective advantages of the rigid body limit equilibrium method and finite element strength reduction method, and overcome the inescapable shortcomings of these methods.In this paper the finite element limit equilibrium method was used into the gravity dam deep sliding stability analysis. The results show a consistent applicability with the traditional rigid body limit equilibrium method and finite element strength reduction method, and it is able to receive the most dangerous non-circular critical slip surface practically and reduce the calculation workload. Through the analysis and discussion in the stability of gravity dam during the layered construction, water storage and seepage, consistent results and conclusions were obtained in practical engineering, further the practicability of the limit equilibrium method in finite element analysis of the problems of the stability of gravity dam were verified. Thus it is a theory in stability analysis with great prospects for development.