摘要: |
利用山东地区实测的Ⅱ类场地358 个钻孔和Ⅲ类场地140 个钻孔的地震动峰值加速度,计算了各个钻孔不同超越概率的土层地震动峰值加速度的放大系数ks,结果表明:(1) 同类场地土层放大系数ks值总体符合正态分布,既有相对集中性,也有离散性;(2) 随着基岩面输入地震动强度的增大,ks值降低,且Ⅲ类场地ks值降低较Ⅱ类的更为明显;(3)Ⅱ类场地随着基岩输入面埋深的增加,ks值呈增加趋势,约达20m 深后基本趋于稳定,而Ⅲ类场地基岩输入面埋深的增加对ks值的影响不甚显著;(4)Ⅱ类场地50 年超越概率10% 的平均ks值(1. 47) 略高于《中国地震动参数区划图》使用的全国平均ks值。本文尝试讨论了山东地区Ⅱ、Ⅲ类场地不同强度基岩峰值加速度输入的ks调整值。 |
关键词: 场地 土层 地震动 峰值加速度 放大系数 |
DOI: |
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基金项目:山东省地震工程研究院支持的课题 |
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Exploration for amplification effects of peek ground motion in the sites of typesⅡ& Ⅲ in Shandong Province |
Diao Ting1,2
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1.Shandong Institute of Earthquake Engineering,Jinan 250021,China;2.Guilin University of Technology,Guilin 541004,China
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Abstract: |
In this paper,amplification coefficient ( ks ) of peek ground motion with different exceedance probability in types Ⅱ and Ⅲ sites,Shandong Province was estimated by analyzing the data of seismic response of soil layer from 358 and 140 drills from types Ⅱ and Ⅲ sites separately. From the results,one can conclude that: (1) the scatter plot of ks data shows that it generally obeys normal distribution; (2) ks decreases with the increase of the strength of incident ground motion,a phenomenon more apparent in type Ⅲ sites than in type Ⅱ sites; (3) for type Ⅱ site,with the increase of depth of the top surface of bedrock where ground motion incident,ks would increase gradually to a stable value until it reaches a depth up to approximately 20 meters or larger,while type Ⅲ site ks is normally insensitive to the depth; (4) the average of ks for type Ⅱ site is 1. 47,slightly larger than that used in the Seismic Ground Motion Parameter Zonation Map of China ( GB18306 - 2001 ) . The paper also discusses the rectified value of ks for different strength of incident ground motion in type Ⅱ and Ⅲ sites in Shandong Province. |
Key words: Seismic ground motion Peak ground acceleration Site condition Exceedance probability |