摘要
深软海床上修建跨海通道并确保其地震安全是一项重大的工程挑战。选取拟建琼州海峡海底隧道沿线4个典型钻孔剖面进行一维非线性地震反应分析,研究了输入地震动特性、土体动力本构模型的选取对海床非线性地震反应特性的影响。结果表明:与MKZ模型相比,DCZ模型能更好地模拟地震动的某些高频和中-长周期分量在海床土层中的传播;海床35 m以浅和80 m~160 m深土层对0.6 Hz~1.1 Hz地震波传播的放大效应显著。对于0.2 g基岩地震动水平,海床地表峰值加速度达0.297 g,相当于地震烈度Ⅷ度水平,这与历史最大影响烈度是一致的;依据海床场地效应特征,累积绝对速度CAV是一个更合适的地震动强度指标。在周期0.05 s~0.5 s范围内,依据《中国地震动参数区划图》反应谱设计跨海通道将偏于不安全。
Building a sea-crossing projects constructed on the deep soft marine deposits subjected to might strong earthquakes and ensuring its seismic safety is a major engineering challenge. The typical four borehole profiles along the subsea tunnel crossing under the Qiongzhou Strait were selected to analyze the one-dimensional nonlinear site response. In the site response analysis, regional seismicity and bedrock motion characteristics, the engineering geology characteristics, and the DCZ and MKZ constitutive models for characterizing nonlinear hysteretic behavior of soil are considered in detail. The results imply that the DCZ model provides better ability to propagate the propagation of some high frequencies and medium-long period components through seabed deposits than the MKZ model. The significant amplification of seismic wave components ranging 0.6 Hz~1.1 Hz within the soils of 35 m and 80 m~160 m below the seabed surface are observed. For bedrock motion levels of 0.2 g, the calculated peak ground acceleration at the seabed surface is 0.297 g, corresponding to seismic intensity Ⅷ level,which is consistent with historical maximum earthquake effect intensity. The cumulative absolute velocity(CAV)is a more suitable proxy to characterize ground motion intensity measure according to the calculated characteristics of seabed site effects. The spectral accelerations given in the "Seismic ground motion parameters zonation map of China" at the periods from 0.05 s~0.5 s exist adverse consequences for seismic design of sea-crossing projects.
作者
陈国兴
夏高旭
王彦臻
金丹丹
CHEN Guo-xing;XIA Gao-xu;WANG Yan-zhen;JIN Dan-dan(Institute of Geotechnical Engineering,Nanjing Tech University,Nanjing,Jiangsu 210009,China;Civil Engineering and Earthquake Disaster Prevention Center of Jiangsu Province,Nanjing,Jiangsu 210009,China;Faculty of Civil Engineering and Mechanics,Jiangsu University,Zhenjiang,Jiangsu 212013,China)
出处
《工程力学》
EI
CSCD
北大核心
2022年第5期75-85,共11页
Engineering Mechanics
基金
国家重点研发计划项目(2017YFC1500403)
国家自然科学基金项目(51438004)。
关键词
场地效应
海床场地
琼州海峡
地震反应特性
土的非线性效应
site effect
seabed site
Qiongzhou strait
seismic response characteristics
nonlinear soil effect
