基于工程钻孔资料的VS30估算新型模型
A New Model for Estimating VS30 Based on Engineering Boreholes Data
张炜超 1任浩 1田勤虎 1孙昱1
作者信息
- 1. 陕西省地震局,陕西西安 710068;陕西西安地球深部构造中国地震局野外科学观测研究站,陕西西安 710068
- 折叠
摘要
地表以下 30 m深度的平均剪切波速(VS30)是评价场地条件及场地地震影响的重要参数.我国存在大量深度小于 30 m的钻孔数据,此类钻孔无法直接计算得到VS30,阻碍了VS30 相关研究成果的推广应用,因此准确估算VS30 尤为重要.基于陕西关中平原 4 个城市 590 个孔深大于 30 m的钻孔测井数据,采用拟合、对比方法开展VS30 估算模型研究.研究发现:钻孔不同深度的平均剪切波速(深度Z<30 m)及孔口高程与实算VS30 沿深度呈现较强的对数线性相关性,并由此提出了基于钻孔不同深度平均剪切波速及孔口高程的VS30 估算对数线性外推新型模型,简称双因素影响外推估算模型.相比速度梯度、双深度参数模型,在计算深度取值越小时,新型模型估算精度越高,稳定性越好,优势越突出.
Abstract
The average shear wave velocity to a depth of 30 m below the ground surface(VS30)is an important parameter for evaluating the site condition and the site earthquake response.There are a large number of borehole data with depths of less than 30 m in China,and these borehole data cannot be directly used to calculate VS30 by definition equation code.Under this situation,referencing the correlated research results which include the parameter of VS30 were prevented.It is important to estimate VS30 accurately.Using the data of 590 boreholes with depths greater than 30 m in Guanzhong plain of Shaanxi Province to research the VS30 estimation model.The results show that the average shear wave velocity at different depths(Z<30 m)and the elevation of the borehole have a strong log-lin-ear relationship with the measured value of VS30 along the depth,so a new model of log-linear extrapolation,which comprehensively considers the average shear wave velocity at different depths and the elevation of the borehole,was proposed.Compared with the velo-city gradient extrapolation model and the double-depth parameter extrapolation model,when the calculation depth is smaller,the new model has higher estimation accuracy and better stability,and this advantage is more prominent.
关键词
关中平原/剪切波速/孔口高程/双因素影响模型Key words
Guanzhong plain/shear wave velocity/elevation of the borehole/new model of two-factor influence引用本文复制引用
出版年
2024
NETL
NSTL
万方数据