Prediction of the Ultimate Aseismatic Capacity of Zhen'an Concrete Face Rock-Fill Dam at a Gradient Valley

摘要

The Zhen'an pumped-storage power station is located at a gradient valley in Shanxi Province, China. Its concrete face rock-fill dam of the upper reservoir is about 125.9m in height. The seismic response characteristics of dam body under design earthquake condition are calculated by using the three-dimensional nonlinear finite element method and the Hardin-Dernevich model. Specifically, the acceleration response, the displacement response, and the stress response of rock-fill dam body, and face slab, the permanent deformation, and the maximum shear stress of dam, etc. are all obtained. Moreover, the earthquake-resistance safety of dam is evaluated, and the ultimate aseismatic capacity of dam under checking earthquake is predicted using overloading method. Results show that the distribution laws of displacements and stresses of dam is consistent with the general rule, but the sloping valley terrain impacts the local deformation and stress of dam significantly. Under normal water level and design earthquake condition with peak acceleration 186.00cm/s~2, the maximum acceleration response along the upstream-downstream direction is 8.70m/s~2 at downstream of dam crest; the maximum displacement response is 94.5mm; the maximum shear stress of dam body is 337kPa and the permanent settlement is 56.7cm. Additionally, the ultimate aseismatic capacity calculated by overload method is about 760gal, which indicates that the seismic safety of dam body meets requirement.