Near-surface site characterization at Quriyat City, Sultanate of Oman using HVSR and MASW techniques
Near-surface site characterization at Quriyat City, Sultanate of Oman using HVSR and MASW techniques
复制标题
使用 HVSR 和 MASW 技术对阿曼苏丹国古里亚特市的近地表场地进行表征
DOI：
10.1007/s12517-015-2061-7
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发表时间：
2015
影响因子：
--
通讯作者：
S. El
中科院分区：
文献类型：
--
作者：
A. Mohamed;I. El;A. Deif;K. Al;Z. Al;S. El
近地表结构对地震动的影响是地震动放大的一个重要因素，特别是软弱的沉积物覆盖层对地震动有很强的放大作用。控制放大率最大的软层参数是基频和剪切波速度。受这些因素影响的地震动频带取决于沉积层的厚度和速度。为了调查和表征阿曼苏丹国Quriyat沿海城市下的近地表结构，中村的技术，这是其特征在于的水平-垂直频谱比（HVSR）的环境噪声测量估计的基本频率在70个站点。剪切波速度是针对特定场地条件的建筑物设计中的重要工具，并且是工程性质的诊断工具。在Quriyat市的40个站点进行了面波多通道分析，以评估近地表剪切波速度。发现基本频率在2.0 Hz（占据沿海软土区域）和23.3 Hz（占据靠近硬岩的区域）的范围内。30 m深度的平均剪切波速度（Vs 30）范围为225 m/s（根据NEHRP场地分类标准，D级，覆盖沿海地区）至1058 m/s（B级，覆盖硬岩附近地区）。结果表明，环境振动的HVSR值与VS 30值吻合较好。VS 30值较低的区域表现出较低的基频，覆盖区域具有相当大的软土厚度，反之亦然。
It is well known that the effects of near-surface structures on ground shaking represent an important factor in earthquake ground motion amplification; in particular, soft sedimentary cover could strongly amplify the seismic motion. The parameters of the soft layer that controls the amplification most are the fundamental frequency and the shear-wave velocity. The frequency band of the ground motion that is affected by such factors depends on the thickness and the velocity of the sedimentary layers. In order to investigate and characterize the near-surface structures beneath Quriyat coastal city in the Sultanate of Oman, Nakamura’s technique which was characterized by the horizontal-to-vertical spectral ratio (HVSR) of the ambient noise measurements was used to estimate the fundamental frequency of the soft soil at 70 sites. The shear-wave velocity is an important tool in the design of buildings for site-specific conditions and is a much more diagnostic tool for engineering properties. The multichannel analysis of surface waves (MASW) was carried out at 40 sites at Quriyat City in order to evaluate the near-surface shear-wave velocities. The fundamental frequencies were found to be in the range of 2.0 Hz (occupying the coastal soft soil area) and 23.3 Hz (occupying the area close to the hard rock). The average shear-wave velocities down to 30 m depth (Vs30) ranged from 225 m/s (class D according to NEHRP standard for site classification and covering the coastal area) to 1058 m/s (class B covering the area in vicinity of hard rock). The results demonstrate that the HVSR of ambient vibrations were in a good agreement with the values of VS30. Areas of lower VS30values exhibit lower fundamental frequency and cover areas with considerable soft soil thickness and vice versa.