Three-Dimension Nonlinear Finite Element Analysis Of Particular Blocks On The Left-Bank Dam Abutment In BAIHETAN Arch Dam

Arch dam is a famous hydraulic structure, and the safest among all structures. Thanks to its economic use of materials and potentiality in overload capacity, arch dam enjoys a wide range of applications. Currently, with the unceasing improvement of the conservancy reconnaissance, design and construction level in our country, some arch dams can be built under the relatively poor geological conditions, which requires engineers to analyze the dam abutment anti- sliding stability aiming at arch dams with complex geological conditions to ensure safety and stability of arch dams.With the three-dimension nonlinear FEM, this paper considers geological structures including F17 (F16, F14), LS3318 and LS331 to study the stability of particular blocks on the left-bank dam abutment in BAIHETAN arch dam. The main contents and achievements are as follows:Firstly, before any foundation treatments, the paper conducts a nonlinear finite element analysis of the BAIHETAN arch dam and foundation. The analysis includes the deformation and stress state of the arch dam, the plastic zone distribution, point-and-area safety coefficient distribution of all construction surfaces and the evaluation of the stability of particular blocks on the left-bank dam abutment. As for the basic load combination, the shear safety coefficients of two blocks are 3.17 and 3.28 respectively; for the special load combination, the shear safety coefficients of two blocks are 3.19 and 3.29 respectively. The above figures indicate that under the circumstance of basic load combination, the shear safety coefficients of block I and block II are both less than the standard 3.50. Therefore, treatments need to be applied to the foundation.Secondly, with reinforcement measures, the paper makes a nonlinear finite element analysis of the BAIHETAN arch dam and foundation and establishes a finite element model for reinforcement measures. The purpose of the model is to study the deformation and stress state of the arch dam and evaluate the stability of left-bank dam abutment blocks after foundation treatments. With reinforcement measures, the shear safety coefficients of two blocks reach 4.44 and 6.25 respectively for the basic load combination, and 4.25 and 6.03 respectively for the special load combination. The figures satisfy the standard.Thirdly, this paper analyzes the effect of the reinforcement measures and makes a comparative analysis of the distribution of foundation stress deformation and the stability of dam abutment blocks. Based on the research results, this paper proves that the BAIHETAN arch dam has a reasonable shape and the potential foundation treatment measures can effectively improve the anti-sliding stability of left-bank dam abutment blocks.