沥青混凝土心墙砂砾石坝耐震时程法性能评估

Seismic performance assessment of asphalt concrete core sandgravel dams based on endurance time analysis

为研究耐震时程分析法在沥青混凝土心墙砂砾石坝抗震性能评估中的适用性,以典型百米级沥青混凝土心墙砂砾石坝为研究对象,基于目标反应谱优化合成的4条耐震加速度时程曲线作为地震动输入,同时选取10条实测地震动进行增量动力分析,对比研究该沥青混凝土心墙砂砾石坝在不同强度地震作用下的坝顶加速度、动位移、相对震陷率等动力响应指标。结果表明:耐震时程分析法能较好预测沥青混凝土心墙砂砾石坝在不同强度地震作用下的动力响应,其结果处于增量动力分析结果的包络线之内,有效避免了多次调幅计算,提高了计算效率,能为我国西部沥青混凝土心墙砂砾石坝的抗震性能评估提供更高效可行的新方法。

To evaluate the applicability of the endurance time analysis(ETA)in the seismic performance evaluation of asphalt concrete core sand-gravel(ACCSG)dams,this study selects ten records of measured ground motions for incremental dynamic analysis(IDA),and compares the acceleration,dynamic displacement,and relative dam crest settlement ratio for different ground motion intensities.We use a typical 100 m level ACCSG dam as the study case and four endurance time acceleration curves(ETAC)synthesized through optimizing target response spectra as the ground motion inputs.The results show that ETA better predicts the dynamic dam responses to different seismic intensities,and its calculations fall in the enhanced dynamic analysis envelope.The calculated seismic responses feature a narrow scatter range,verifying that ETA can avoid multiple calculations for amplitude modulation and improve computational efficiency and accuracy,and that it is a more efficient and feasible new method for seismic performance assessment of the ACCSG dams in Western China.