DEVELOPMENT OF REAL-TIME GEOPHYSICAL EXPLORATION SYSTEM BASED ON ARRAY OBSERVATION OF THREE-COMPONENT MICROTREMORS

现场技术和分析程序已提出的岩土工程场地特性，使用微动三分量地面运动，除了其适用性评估土壤剖面和地面运动特性的空间变化。本系统可以很容易地提供瑞利波和洛夫波频散曲线，以及H/V谱的脉动三分量地震动的频谱分析。从理论上导出了表面波的色散曲线和H/V谱，其中可以考虑高阶模的影响。本文提出了用瑞利波频散曲线和洛夫波频散曲线或H/V谱来反演横波速度剖面的方法，结果表明：（1）在任何情况下，瑞利波理论频散曲线都与脉动垂直运动的F-k谱分析结果吻合得很好。(2)理论色散曲线 关于我们 当地脉动从一个方向传播时，Love波与地脉动横向水平运动的F-k谱分析结果吻合较好。(3)所提出的面波H/V谱与观测到的地脉动H/V谱具有较好的一致性，证明了其有效性。(4)本文提出的利用瑞利波频散曲线和Love-wave频散曲线或H/V谱反演横波速度剖面的方法比仅利用瑞利波频散曲线反演横波速度剖面的方法更可靠。在钏路和科比进行了利用台阵的脉动测量，并估计了这些地区的剪切结构，其深度分别为50 m和1.5 m公里，分别。计算结果与传统方法计算结果吻合较好，表明了该方法的有效性。有效的应力响应分析，然后使用估计的土壤剖面。计算得到的地面峰值速度和加速度的分布以及台站间的传递函数与地震时的观测结果基本一致，表明本文方法是可行的。少

Field techniques and analytical procedures have been presented for geotechnical site characterization using microtremor three-component ground motions, in addition to their applicability for evaluating spatial variation of soil profiles and ground motion characteristics. The present system can readily provide Rayleigh- and Love-wave dispersion curves as well as H/V spectra from spectrum analyzes of microtremor three-component ground motions. The dispersion curves and H/V spectra of surface waves have been theoretically derived in which the effects of higher-modes can be taken into account. Inverse analyzes using both Rayleigh-wave dispersion curve and Love-wave dispersion curve or H/V spectra have been presented for determining shear wave velocity profiles.It is shown that :(1) The theoretical dispersion curve of Rayleigh waves shows a good agreement with those determined by te F-k spectrum analysis of the microtremor vertical motions in any case.(2) The theoretical dispersion curve of … More Love waves shows a good agreement with those determined by the F-k spectrum analysis of the microtremor transverse horizontal motions, if microtremors propagate from one direction.(3) The proposed H/V spectrum of surface waves shows a good agreement with observed microtremor H/V spectrum, claiming its validity.(4) The proposed inversion process using both Rayleigh-wave dispersion curve and Love-wave dispersion curve or H/V spectra can yield more reliable shear wave velocity profiles than that using Rayleigh-wave dispersion curve only.To demonstrate the effectiveness of the proposed methods, microtremor measurements using arrays are conducted in Kushiro and Kobe and the shear structures in those areas are estimated down to depths of about 50 m and 1.5 km, respectively. The estimated shear structures are in good agreement with those determined by the conventional methods, indicating the effectiveness of the proposed method. Effective stress response analysis is then made using the estimated soil profiles. The computed distribution of the peak ground velocity and acceleration as well as the transfer funcion between stations are consistent with those observed during the earthquakes, suggesting that the proposed methods are promising. Less