海域不同类别场地地震动参数变化规律研究

基于海域场地分类标准,选取南海海域实测钻孔作为计算模型,同时人工构造部分钻孔计算模型,对126条不同特性地震动输入下5种类别场地计算模型开展土层反应分析计算,分析不同地震动输入下不同海域场地峰值加速度和特征周期变化规律。结果表明,场地类别和地震动输入强度显著影响峰值加速度放大系数和特征周期,场地土越软,地震动输入强度越大,峰值加速度放大系数越小,特征周期越大。根据研究结果给出不同地震动输入下不同海域场地峰值加速度放大系数、特征周期变化范围,为海域场地工程抗震设防和编制海域地震动参数区划图提供参考。

Study on the Change of Earthquake Ground Motion Parameters for Different Classification Sites of Ocean Areas

Based on site classification standards for ocean areas, the boreholes in the South Sea of China are selected as calculation model for site response. Due to the insufficiency of ocean geological data, some boreholes are also constructed for site response. By using 126 ground motions with different characteristics, site response was conducted for 5 kinds of classification sites. The change of peak acceleration and characteristic period under different input motions for different site classifications is analysized. Results show that site classifications and peak acceleration of input ground motion greatly influenced the amplification coefficients of peak acceleration and characteristic periods. The conclusion are as follows: amplification coefficient becomes smaller and characteristic period becomes longer when the site goes softer and input motion goes stronger. The variation range of amplification coefficients and characteristic periods under different input motions and site classifications are concluded. The results can be inferred to anti-seismic design of ocean engineering structures and to the earthquake ground motion parameters zonation of ocean areas.