摘要
无黏性土的液化与孔隙水压力密切相关,能直接测试孔隙水压力的孔压静力触探(CPTU)原位测试技术在土体液化势评价方面具有独特的优势。采用严格的数学方法推导了基于CPTU测试技术的液化概率评价模型。新的概率模型以映射函数的形式表示,该映射函数将液化概率P_(L)与基于CPTU的确定性模型中得到的安全系数F_(s)相关联,其中CPTU确定性模型是通过核极限学习机算法和稳健搜索技术建立的。该新的概率性模型考虑了模型固有的不确定性和参数的不确定性,同时对该概率模型进行对比分析。结果表明:当安全系数F_(S)为1时,液化发生的概率P_(L)为15.2%。该新模型的明显优势在于它直接使用CPTU数据,更符合液化行为现象,同时适用于砂质土和粉质土。该新模型无需钻孔取样室内试验,即可进行完整的液化评估或初步筛选。最后用中国唐山地震液化案例说明所提新概率模型考虑模型和参数不确定性的应用。
The liquefaction of cohesionless soils is closely related to the pore water pressure.The in situ testing technology,piezocone penetration test(CPTU) which can directly measure the pore water pressure,has unique advantages in liquefaction evaluation.In this study,a CPTU-based model for assessing the probability of liquefaction is derived by a rigorous mathematical method.The new probabilistic model is expressed in the form of a mapping function that relates the liquefaction probability mathematically to the factor of safety obtained from the CPTU-based deterministic model,which is established by the kernel extreme learning machine algorithm and the robust search technology.The new probabilistic model considers the inherent model uncertainty and parameter uncertainty,and makes a comparative analysis of the probabilistic model.The results show that the factor of safety(F_(S)) of 1 yields a probability of liquefaction(P_(L)) of 15.2%.The obvious advantage of the new model is that it directly uses the CPTU data,which is more suitable for the phenomenon of liquefaction behavior,and is suitable for sandy soil and silty soil.The new model can be used for liquefaction evaluation or preliminary screening without the need of additional sampling and laboratory testing.Finally,a liquefaction case of Tangshan earthquake in China is used to illustrate the application of the proposed probabilistic model considering the uncertainties of model and parameters.
作者
段伟
蔡国军
赵泽宁
刘松玉
董晓强
DUAN Wei;CAI Guojun;ZHAO Zening;LIU Songyu;DONG Xiaoqiang(College of Civil Engineering,Taiyuan University of Technology,Taiyuan 030024,China;Institute of Geotechnical Engineering,Southeast University,Nanjing 211189,China;School of Civil Engineering,Anhui Jianzhu University,Hefei 230601,China;AnhuiInstitute of Intelligent Underground Detection Technology,Hefei 230601,China)
出处
《岩土工程学报》
EI
CAS
CSCD
北大核心
2023年第1期66-74,共9页
Chinese Journal of Geotechnical Engineering
基金
国家重点研发计划项目(2020YFC1807200)
国家杰出青年科学基金项目(4222506)
国家自然科学基金项目(52108332,41877231,42072299)
安徽省智能地下探测技术研究院开放课题(AHZT2022KF001)。
关键词
孔压静力触探
孔压参数比
砂质土
粉质土
液化概率
piezocone penetration test
pore pressure ratio
sandy soil
silty soil
probability of liquefaction
作者简介
段伟(1989-),男,山西太原人,博士,从事现代原位测试技术等方面的研究工作。E-mail:zbdxdw@163.com;通信作者:蔡国军,E-mail:focuscai@163.com。
