工程地震中vS30估算模型及其应用研究进展

vS30 Estimation Model and Its Application in Earthquake Engineering

摘要:

在工程地震场地条件评价中，地表以下30 m深度范围内的等效剪切波速（v_S30）是一个重要的分类参数，但由于客观条件的制约，在很多实例中等效剪切波速度的计算深度未达到30 m，因此如何更好地估算v_S30就变得尤为重要。详细阐述v_S30估算模型的演化发展：首先介绍基于钻孔测井数据的3类模型，即常速度外推模型、速度梯度模型、双深度参数外推模型；然后详述基于地质、地形坡度和地貌等替代指标的v_S30估算模型，以及基于HVSR的反应谱比的估算模型。文章分析各模型的特点和适用性，同时在此基础上简述了v_S30在现今工程地震领域的应用。

Abstract:

In earthquake engineering, the equivalent shear-wave velocity to a depth of 30 m below ground surface (v_S30) is a significant parameter in evaluating site conditions. In many cases, however, because of the restrictions of objective conditions, shallow shear-wave velocity profiles do not extend to a depth of 30 m; therefore, it is important to find a better way to estimate v_S30. The development of v_S30 estimation model is comprehensively introduced in this paper. First, three models (bottom-layer constant velocity model, velocity gradient model, and the extrapolation model with the travel-time averaged shear-wave velocities at two different depths) based on logging data are discussed, and then a v_S30 estimation model based on some proxies and an estimation model based on horizontal-to-vertical spectral ratio response are described. Considering the characteristics and applicability of the involved estimation models, the use of v_S30 model in modern earthquake engineering is simply described.