基于地质属性和地形特征的场地参数vS30估算方法

A method for estimating site vS30 based on geological attributes and topographic features

摘要:

平均剪切波速是地震工程领域中一个非常重要的参数,可用于预测场地的抗震性能和响应特性。利用甘肃省的钻孔资料、DEM数据以及1∶25万地质图,建立一种综合考虑地质属性和多项地形因子的^vS30估算方法,并与传统的^vS30估算方法进行对比验证。结果表明:地质属性和地形特征在场地^vS30估算中具有较强的指示作用;在划分地质单元的基础上,引入地形坡度、表面纹理、局部凸度,以及最邻近河网高差指数等4项地形因子建立的甘肃省场地参数^vS30估算方法,在河西走廊、黄土高原等地质属性和地形特征差异明显的地区,其估算精度高于传统的^vS30估算方法。所提方法得到的^vS30估算结果可为甘肃省场地参数^vS30值的确定提供参考,还可为地质属性和地形特征差异显著地区^vS30值的估算提供一种新思路。

Abstract:

As a crucial parameter in earthquake engineering,the average shear wave velocity playing a pivotal role in predicting the seismic performance and response characteristics of a specific site.This study introduces a comprehensive method for ^vS30 estimation,integrating geological attributes and diverse terrain factors.By utilizing drilling data,digital elevation model data,and 1∶250 000 geological map of Gansu Province,the proposed method undergoes a comparative validation against conventional ^vS30 estimation methods.The results show that geological attributes and topographical features have a strong indication in the ^vS30 estimation of specific sites.Based on the division of geological units,the proposed estimation method of ^vS30 in Gansu Province was established by introducing four topographic factors,namely,topographic slope,surface texture,local convexity,and height above nearest drainage.In regions characterized by marked disparities in geological attributes and terrain features,such as the Hexi Corridor and Loess Plateau,the estimation accuracy of the proposed method is higher than that of the traditional methods.The estimation results of ^vS30 obtained by the proposed method can provide a reference for determining the value of ^vS30 in Gansu Province,and also provide a new idea for estimating the value of ^vS30 in areas with significant differences in geological attributes and topographic features.