摘要
以国内外23次地震中200组场地液化实测数据为基础,通过Logistic回归分析,建立关联修正标准贯入击数N160cs与循环应力比CSR的液化概率模型。以50%液化概率水平为液化与非液化的临界点,建立了指数形式的抗液化应力比CRR计算式,新建概率模型预测饱和砂土液化与非液化的成功率分别为85.71%和76.14%,具有较高的可靠性。与已有模型比较,使用了新的数据和修正系数,消除了一些不合理的偏差,总体判别结果偏于安全。为了将确定性分析方法与概率分析方法联系起来,建立了抗液化安全系数FS与液化概率PL的关系式。算例结果表明,新建概率模型简单、实用、可靠。
A simple model for evaluating liquefaction probability using standard penetration test （SPT） data is developed based on logistic regression analysis of 200 sets case histories of 23 earthquakes. The proposed model uses corrected blow count （N160cs and cyclic stress ratio （CSR） as input parameters. When liquefaction probability level is equal to 50 % as a limit state, the formulation of cyclic resistance ratio （CRR） was proposed with an exponent and the proposed model＇s reliability for liquefaction and non-liquefaction estimation of saturated sands is 85.71% and 76.14 %, respectively. Comparisons of the proposed probability model with previously proposed deterministic and probabilistic approaches are performed to demonstrate the slightly conservation, because the new test data and modified coefficients are used in this analysis, so some sources of uncertainty and variance are eliminated. In order to correlate deterministic approach and probability approach, the relationship between the factor of safety against liquefaction and liquefaction probability is proposed. Five case records are further analyzed to demonstrate the feasibility and reliability of the proposed method.
出处
《岩土力学》
EI
CSCD
北大核心
2008年第9期2567-2571,共5页
Rock and Soil Mechanics
基金
国家自然科学基金项目(No.50578029)
教育部创新团队发展计划(No.IRT0518)
关键词
液化评价
回归模型
标准贯入
砂土
地震
liquefaction evaluation
regression model
standard penetration test
sand
earthquake
作者简介
潘建平，男，1978年生，博士研究生，主要从事岩土工程方面的教学科研工作。E-mail：pjp4057@sohu.com
