Estimating the Shear Velocity Profile of Quaternary Silts Using Microtremor Array (SPAC) Measurements
Estimating the Shear Velocity Profile of Quaternary Silts Using Microtremor Array (SPAC) Measurements
复制标题
使用微震阵列 (SPAC) 测量估算第四纪粉土的剪切速度剖面
DOI：
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发表时间：
2005
期刊：
影响因子：
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通讯作者：
M. Asten
中科院分区：
文献类型：
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作者：
J. Roberts;M. Asten
我们已经使用的微动方法，与阵列的直径达96米，进行非侵入性估计剪切波速度剖面的深度为30至50米，在松散的第四纪亚拉三角洲沉积物。两个粉砂单元（Coode Island粉砂和Fishermans弯曲粉砂）主导了我们的解释;该方法得出这些单元的剪切速度，精度为5&，并区分前一个较软的单元（Vs = 130 m/sec）和后一个较硬的单元（Vs = 235 m/sec）。在这些淤泥下面，该方法解析出与已知砾石（Vs 500至650米/秒）相关的坚固单元。使用表面导线与单站H/V频谱比的方法，我们表明，在厚度的变化，软粉土可以迅速映射，但只能定性。地质剖面的复杂性要求在需要定量剪切波速度剖面时使用阵列方法。
We have used the microtremor method, with arrays of up to 96 m diameter, to carry out non-invasive estimation of shearwave velocity profiles to a depth of 30 to 50 m in unconsolidated Quaternary Yarra Delta sediments. Two silt units (Coode Island Silt, and Fishermans Bend Silt) dominate our interpretation; the method yields shear velocities for these units with precision of 5&, and differentiates between the former, softer unit (Vs = 130 m/sec) and the latter, firmer unit (Vs = 235 m/sec). Below these silts, the method resolves a firm unit correlating with known gravels (Vs500 to 650 m/sec). Using surface traverses with the single-station H/V spectral ratio method, we show that the variation in thickness of the softer silt can be mapped rapidly but only qualitatively. The complexity of the geological section requires that array methods be used when quantitative shear-wave velocity profiles are desired.