水电能源科学

以某抽水蓄能电站下水库沥青混凝土心墙堆石坝为例，通过三维非线性有限元地震反应计算，从坝体、心墙和防渗墙地震反应等方面分析了大坝的抗震安全性。结果表明，设计地震PGA 0.95 m/s²作用下，坝体顺河向、坝轴向、竖向动位移极值分别为3.00、2.15、1.26 cm,加速度极值分别为3.25、3.30、3.27 m/s²,相应的放大倍数分别为3.42、3.47、3.44;竖向永久变形极值为-8.21 cm,震陷率为0.10%。沥青混凝土心墙顺河向、坝轴向、竖向动位移极值分别为2.99、2.02、1.23 cm,加速度极值分别为3.25、3.26、3.04 m/s²;静动应变叠加后的心墙大、小主应变极值分别为2.01%、-0.85%;心墙竖向永久变形、震后变形极值分别为-5.99、-24.78 cm。防渗墙顺河向、坝轴向、竖向动位移极值分别为0.29、0.09、0.05 cm;静动应力叠加后的大、小主应力极值分别为7.61、-1.38 MPa。综合分析计算成果，坝体动位移和加速度分布及极值合理，沥青混凝土心墙拉应变和坝基混凝土防渗墙拉应力均未超标，因此大坝满足抗震安全性要求。

Taking the asphalt concrete core rockfill dam of the lower reservoir of a pumped storage power station as the research object, the seismic safety of the dam was analyzed from aspects of the seismic responses of the dam body, core wall and anti-seepage wall through three-dimensional nonlinear finite element seismic response calculation. The results show that under the action of PGA 0.95 m/s², the extreme values of dynamic displacement of the dam along the river, axial and vertical direction of the dam are 3.00 cm, 2.15 cm and 1.26 cm, respectively. The extreme values of acceleration along the river, axial and vertical direction of the dam are 3.25 m/s², 3.30 m/s² and 3.27 m/s², respectively, and the corresponding magnifications are 3.42, 3.47 and 3.44. The extreme value of vertical permanent deformation is-8.21 cm, and the seismic subsidence rate is 0.10%. The extreme values of dynamic displacement of asphalt concrete core wall along the river, axial and vertical direction of the dam are 2.99 cm, 2.02 cm and 1.23 cm, respectively. The extreme values of acceleration along the river, axial and vertical direction are 3.25 m/s², 3.26 m/s² and 3.04 m/s², respectively. The extreme values of the major and minor principal strains of the core wall after the superposition of static and dynamic strains are 2.01% and-0.85%, respectively. The extreme values of vertical permanent deformation and post-earthquake deformation of the core wall are-5.99 cm and-24.78 cm, respectively. The extreme values of dynamic displacement of cutoff wall along the river, axial and vertical direction are 0.29 cm, 0.09 cm and 0.05 cm, respectively. The extreme values of the major and minor principal stresses after the superposition of static and dynamic stresses are 7.61 MPa and-1.38 MPa, respectively. Comprehensive analysis and calculation results show that the distribution and extreme value of dynamic displacement and acceleration of dam body are reasonable, and the tensile strain of asphalt concrete core wall and tensile stress of dam foundation concrete cutoff wall are not beyond the standard, so the dam meets the requirements of seismic safety.