四川省Vs30数据构建及其应用-以四川汶川8.0级地震为例

Construction and Application of Vs30 Data in Sichuan Province - Taking the 8.0 magnitude Wenchuan Earthquake in Sichuan Province as an Example

摘要:

地下30m平均剪切波速作为场地划分的一项重要参数，在国内外建筑和构筑物的抗震设计规范以及局部场地影响的校正中得到广泛应用。然而，目前在中国地区使用广泛的USGS提供的地下30m平均剪切波速数据仍需进一步考证其适用性。本研究通过四川省地形坡度与浅层平均波速之间的相关关系以及地下30m平均剪切波速与浅层平均剪切波速之间的相关关系，制作了四川省地下30m平均剪切波速数据（Vs30），并将其应用于四川汶川8.0级地震的地震烈度评估中。结果显示：相较于广泛使用的USGS的地下30m平均剪切波速数据，本研究得到的四川省地下30m平均剪切波速结果与实际情况更为接近，使用本研究得到的地下30m平均剪切波速数据进行场地校正过的四川汶川8.0级地震烈度快速评估结果在重灾区和极重灾区区县的判定上更为准确。本文研究结果可以提高日后四川省地震应急产出的准确性，为震后应急指挥决策、应急救援工作提供第一手参考资料。

Abstract:

The average shear wave velocity at a depth of 30 meters (Vs30) is an important parameter for site classification used extensively in both domestic and international seismic design codes for buildings and structures, as well as for correcting local site effects. However, the applicability of the widely used Vs30 data provided by the USGS for the China region still requires further verification. In this study, the correlation between the terrain slope in Sichuan Province and the shallow average wave velocity, as well as the relationship between the Vs30 and shallow average shear wave velocity, were used to produce a Vs30 dataset for Sichuan Province. This dataset was then applied to the seismic intensity assessment of the magnitude 8.0 Wenchuan earthquake in Sichuan. The results show that the Vs30 results for Sichuan Province obtained from this study are closer to the actual situation compared to the widely used USGS Vs30 data. The rapid assessment of seismic intensity for the Wenchuan earthquake using the Vs30 data from this study yielded more accurate determinations of the heavily and severely damaged areas. The findings of this study can enhance the accuracy of seismic emergency outputs for Sichuan Province in the future, providing primary reference materials for post-earthquake emergency command decisions and emergency rescue efforts.