深度小于30 m正常停钻V_(S30)预测公式精度分析  

Research on Precision Analyzing to Existing Formulas of Predicating V_(S30)for the Normally Stopping Boreholes with Depths<30 m

作　　者：聂利英[1] 韩刘 邵云澜 冯江江 NIE Liying;HAN Liu;SHAO Yunlan;FENG Jiangjiang(College of Civil and Transportation Engineering,Hohai University,Jiangsu Nanjing 210098,China)

机构地区：[1]河海大学土木与交通学院,江苏南京210098

出　　处：《防灾减灾学报》2024年第1期29-37,54,共10页Journal of Disaster Prevention And Reduction

基　　金：国家重点研发计划资助项目(2016YFC0401807)。

摘　　要：我国钻孔测速中在正常停孔条件下产生大量深度小于30 m的钻孔数据。由于正常停钻,我国几乎没有此类场地下深度超30 m的钻孔实测数据,故无法以同类场地大于30 m数据直接回归V_(S30)公式。国外区域数据建立的V_(S30)预测公式有区域性,其在场地特征类似才适用;针对我国深度小于30 m正常停孔下V_(S30)预测线性外插公式LEE为具有潜在可行性公式。因此,为了从已有公式中得到可靠的V_(S30)预测公式,基于地质宏观类比,在停钻深度没有到30 m数据条件下发展了对已有公式的精度分析方法。通过对平均剪切波速竖向分布特点的分析,提出“精度分析区间”;并在缺乏停钻深度到30 m直接验证数据的前提下,提出两种分析公式预测精度的方法:方法一中校核对象是实测数据,具有一定直接检验的特点,但仅适用于具有反算能力的公式;方法二是基于所有公式都具有的——换算深度越靠近30 m则V_(S30)预测越准确的特点提出的,适用范围广。以滇中引水工程为案例,应用两种方法于该工程中深度小于30 m的正常停钻数据,为该工程选出精度最高公式LEE。In the engineering practice of borehole in China,a large number of boreholes with depth less than 30 m are yield.Because the boreholes are normally stopping,there is almost no borehole data with depth>30 m in China,so it is almost impossible to develop predicting formula of V_(S30)by the borehole data with depth>30m of the same site types.The formulas which are established on boreholes data of foreign regions have site dependency;and the application of the linear extrapolation equation LEE which is established for the boreholes with depth<30 m in China is the potential feasibility.To select the reliable formulas from the existing formulas of predicting V_(S30),on the premise of site characteristics comparison of the existing formulars,the methods of precision analyzing of existing formulas are proposed under the condition of no borehole data from the depth of stopping to 30 m for direct precision check.Based on the investigation of the averaged shear-wave velocity profiles,the depth section for precision analyzing is suggested;and two methods for precision analyzing are proposed.The one method includes checking precision with measured data,and it somehow has the characteristics of direct inspection,but its application is limited in the those formulars which are capable of inverse calculation.The other method has proposed based on the result of all existed predicting formulas that the closer the calculation depth is got to 30 m,the more precise the value of V_(S30)can be estimated,and it can be applied more widely.By taking the Water Diversion Project in Central Yunnan as a case,the two methods are used in the boreholes data with depth<30 m of the Project,and as a result the most precise formular,LEE,is recommended.

关 键 词：V_(S30)预测公式 深度小于30 m钻孔 精度分析 平均剪切波速 

分 类 号：P315.9[天文地球—地震学]