边坡可靠性评价的向量投影响应面研究及应用  

Reliability evaluation of slopes based on vector projection response surface and its application

作　　者：王宇[1] 王春磊 汪灿[1] 曹强[1] 余宏明[1] 

机构地区：[1]中国地质大学(武汉)工程学院,湖北武汉430074 [2]甘肃地质工程勘察院,甘肃张掖734000

出　　处：《岩土工程学报》2011年第9期1434-1439,共6页Chinese Journal of Geotechnical Engineering

基　　金：国家"十一五"科技支撑计划项目(2008BAC47B0);交通部西部交通建设科技项目(200906)

摘　　要：岩土体的力学参数存在一定的随机性,当进行边坡稳定可靠性评价时,当功能函数不能用显式表达时,响应面法成为计算可靠度指标的重要方法。将向量投影响应面法与有限元强度折减法相结合,研究隐式功能函数边坡工程稳定可靠度计算方法。首先利用强度折减法结果拟合稳定系数计算方程从而代替隐式方程,并建立极限状态方程,然后进行向量投影以确定展开点和抽样点,进行近似方程的拟合、验算点和可靠度指标的计算,直到计算达到收敛。通过与不同计算方法进行对比,表明区别于通常以插值点为中心展开生成样本点的向量投影取样法的准确性和合理性,该方法可使可靠性分析次数显著减少,改善了对非线性程度较高的极限功能函数求解可靠指标的收敛性。同时,将该方法应用于杭兰高速公路大水田边坡的稳定可靠性分析当中。The mechanical parameters of rock-soil are random.When evaluating the reliability of the slope,the state function can not be expressed explicitly,thus,the response surface method is applied to solve this problem.A new method of slope reliability analysis is proposed combining the FEM strength reduction method.The results of the strength reduction method are adopted to fit the equation for stability coefficient instead of implicit equation,so a limit state equation is established.The approximate equation of calculation stability coefficient is combined with implicit function and the checking point to decide a new basic point and the sample points.The calculation is performed circularly until the reliability index is converged.The accuracy and rationality of the approximate method,which is different from the traditional interpolation points to generate the sample points for the center of vector projection method,is validated through comparison with the reliability indices calculated by different methods.The analysis frequency is significantly reduced,and the convergence of high degree,and the nonlinear limit function used to analyze the reliable indices is improved.At the same time,the proposed method is applied to the analysis of the stability and reliability of Dashuitian slope on Hangzhou-Lanzhou Highway.

关 键 词：边坡 可靠性评价 向量投影响应面 强度折减法 可靠性指标 

分 类 号：TU452[建筑科学—岩土工程]