摘要
发展了一种基于谱元法和多次透射边界的平面SV波入射下二维复杂场地波动数值模拟方法。基于该方法,模拟分析了31条地震波输入下二维典型层状沉积盆地中的各场点相比其对应的一维土层模型的模拟地震动的附加放大特征,分析了放大系数对于输入地震波的敏感性。结果表明,该方法具有较高精度和良好的高频稳定性。不同地震波输入下,盆地地面运动及其放大特征存在较大差别。水平分量上平均反应谱放大系数的较大值(最大1.2左右)集中在盆地边缘区域及周期等于0.5倍~0.7倍自振周期附近,垂直分量上较大放大系数(最大0.9左右)紧邻盆地角点且周期为0.3倍自振周期处。同时,盆地对不同周期地震动的放大特征,以及不同位置点的谱放大系数随周期的变化规律均表现出明显不同,相对短周期地震动的盆地边缘效应最为强烈,而相对长周期地震动的放大作用明显减弱。此外,盆地边缘区域的放大系数对输入波最为敏感,不同地震波输入下放大系数值在较大范围内变化;而盆地中间区域的放大系数对输入波不敏感,其值的变化范围相对较小。
A numerical method combined the spectral element method and multi-transmitting formula for simulating wave motions of 2D complex site under plane SV wave incidence was developed.Based on this method,and considering 31 distinctive input waves,the additional aggravation features of 2D layered trapezoidal basin relative to the local 1D model,as well as the sensitivity with input waves were investigated.Results show that the proposed method has high accuracy and good stability performance in high frequency.The basin surface motion and aggravation features vary significantly with input signals.For the horizontal component,the large-value average aggravation factor of response spectral(AFRS,with maximum value of 1.2)are concentrated in the basin edge region and at periods around 0.5~0.7 times the resonance frequency of the deepest part.While for the vertical component,large AFRS(maximum value of 0.9)regions are close to the basin corner and at 0.3 times resonance frequency.In addition,there exits considerable difference for aggravation features of basin in different periods,and for the changing trend of AFRS with frequencies.The basin edge effect is the strongest for short-period motions,where the AFRS is most sensitive to incident motions,with its value varies in a large range.However,the aggravations decrease significantly for long-period waves,and the AFRS in the central part of the basin is quite insensitive to input waves,with a value changed in an obvious smaller range.
作者
于彦彦
丁海平
芮志良
YU Yanyan;DING Haiping;RUI Zhiliang(Key Laboratory of Structure Engineering of Jiangsu Province,Suzhou University of Science and Technology,Suzhou 215011,China)
出处
《振动与冲击》
EI
CSCD
北大核心
2024年第4期166-178,共13页
Journal of Vibration and Shock
基金
国家自然科学基金青年基金(51808371)。
关键词
谱元法
多次透射公式
层状盆地
地震动
附加放大特征
spectral element method
multi-transmitting formula
layered basin
seismic motion
additional aggravation feature
