摘要
能量传递率是衡量贯入类试验锤击效率的一个重要指标。国外对这一指标需要进行现场实测,进而修正贯入试验的锤击数,建立评价场地承载力、液化势等特性的标准化锤击数。国内规范中,则较少考虑贯入试验的锤击能量传递率的问题,且缺少现场试验测试数据,导致基于贯入类试验锤击数的地基评价方法难以与国外标准进行横向对比。为解决这一问题,选取川滇地区西昌地震实验场的3个勘察试验点。采用能量测试仪实测标准贯入试验能量传递率,研究我国常规SPT试验装置锤击效率,并评价其稳定性。试验实测结果显示,现场标准贯入试验的锤击能量传递率均值基本超过75%。能量传递率随着贯入深度的增加稍有增加,地表下20 m范围内增长幅值为10%左右。试验结果可为评价我国常规SPT试验设备的锤击效率提供依据。
Hammer efficiency is defined as the energy transfer rate,and is an important index in standard penetration test to evaluate site bearing capacity and to assess liquefaction potential.In standard procedure outside China,the energy transfer rate is usually obtained by real in-situ testing using an energy measurement equipment,and then to correct blow counts.In Chinese codes,however,the energy transferred into the rod during hammering is not considered instead that the uncorrected blow counts are used in engineering practice,which leads to blow counts of standard penetration test obtained in China can hardly be compared with others.To solve this issue,three typical testing sites in Xichang earthquake experiment site are selected to test the hammer efficiency used in the Chinese routine standard penetration test equipment and to evaluate stability of energy transferring.The analytical results indicate that the energy transfer ratio is remarkably stable that the average energy transfer ratios exceed 75%.A slight trend of energy transfer ratio increasing with depth is delineated that the incremental of the energy transfer rate stays about 10%in the depth range of 20m.The energy transfer ratio obtained in the tests can be used to evaluate the current standard penetration test apparatus.
作者
陈龙伟
陈童
王云龙
王维铭
CHEN Longwei;CHEN Tong;WANG Yunlong;WANG Weiming(Institution of Engineering Mechanics,China Earthquake Administration,Key Laboratory of Earthquake Engineering and Engineering Vibration of China Earthquake Administration,Harbin 150080,China;Key Laboratory of Earthquake Disaster Mitigation,Ministry of Emergency Management,Harbin 150080,China;Heilongjiang Institute of Technology,Harbin 150050,China)
出处
《工程地质学报》
CSCD
北大核心
2023年第5期1757-1766,共10页
Journal of Engineering Geology
基金
中国地震局工程力学研究所基本科研业务费专项资助项目(资助号:2020B01).
关键词
标准贯入试验
能量传递率
现场试验
地震实验场
Standard penetration test
Energy transfer ratio(ETR)
In-situ testing
Earthquake test site
