梁桥结构地震反应分析中输入地震动选取及调整方法研究

针对桥梁结构地震动分析时所输入地震动选择会影响时程分析结果的可靠性，结合结构动力放大系数基本原理及地震波能量原理，通过分析反应谱型特点，将其拟合归纳为以结构自振周期 范围及规范规定的0.1s-Tg范围分别定义为低频、高频对比区间，以两个区间反应谱曲线包围面积作为对比参数进行自然地震波选择依据。并据所选地震波提出基于两区间的5种天然地震波调整方法。以典型多跨梁桥为例进行数值分析，以桥墩墩底弯矩、剪力和及墩顶位移作为桥梁地震反应统计量。利用统计分析结果验证双参数地震波选择方法及地震波调整方法的合理性及有效性。

Study on selection of earthquake input and adjustment method in girder bridge seismic response analysis

Time-history analysis method has become the most popular seismic analysis method of bridge structure, however, selection of the input seismic motion is a key factor affecting the reliability of time-history analysis results. Combining the basic principle of structure dynamic amplification coefficient and the energy principle of seismic wave, response spectrum model fitting is summarized as to the rules and regulations of structural natural vibration period ranging from 0.1 s to Tg, which is surrounded by interval response spectrum curve as the basis of the natural seismic wave of comparative parameters. This paper puts forward five adjusting methods of natural seismic records based on the above mentioned two intervals. In addition, numerical analysis of a typical multi-span bridge is carried out to investigate response statistics of bridge pier bottom moment, base shear and pier top displacement. Numerical analysis results prove that the double parameters selection method of seismic record and adjusting criterion are reasonable and effective.