考虑地震力效应的台阶式边坡可靠度分析
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摘要
在地震多发地区,设计和施工都需要考虑地震力作用对边坡稳定性的影响。针对地震力作用下的台阶式边坡稳定性问题,结合极限分析方法和随机响应面法,建立了一种计算效率较高的边坡可靠度分析方法。首先,利用拟静力法将地震力效应转换为作用在边坡水平方向上的荷载,同时将地震力系数和土体特性均视为随机量;然后基于上限法原理和强度折减法,推导得到考虑了地震力效应的台阶式边坡稳定功能函数;由于该方程表达式是一个隐式函数,因此,利用随机响应面法得到原功能函数的近似显式表达式;最后,通过蒙特卡洛法模拟近似的显式函数,最终计算得到边坡的失效概率。通过工程实例的对比分析表明,该方法的精度与传统的蒙特卡洛方法相当,但是计算过程相对简易高效,可以有效地应用于考虑地震力效应的台阶式边坡可靠度分析。
In earthquake-prone areas,the design and construction need to consider the stability of the slope under the action of seismic forces. Aiming at the stability problem of the stepped slope considering the action of seismic force,this paper combines the limit analysis method and the stochastic response surface method to establish a more efficient slope reliability analysis method. Firstly,the quasi-static method is used to convert the seismic force effect into the load acting in the horizontal direction of the slope,and both the seismic force coefficient and the soil characteristics are regarded as random quantities; then,based on the upper bound method and the strength reduction method,the stability performance function of thestepped slope considering the seismic force effect is derived; since the equation expression is an implicit function,the approximate explicit expression of the original function is obtained by the random response surface method; finally,the approximate explicit functionis simulated by Monte Carlo method, andthe failure probability of the slopeis obtained. The analysis of a given engineering example shows thatthe accuracyof this method is equivalent to the traditional Monte Carlo method,but the calculation process is relatively simple and efficient,and can be effectively applied to the stability analysis of stepped slopes.
In earthquake-prone areas,the design and construction need to consider the stability of the slope under the action of seismic forces. Aiming at the stability problem of the stepped slope considering the action of seismic force,this paper combines the limit analysis method and the stochastic response surface method to establish a more efficient slope reliability analysis method. Firstly,the quasi-static method is used to convert the seismic force effect into the load acting in the horizontal direction of the slope,and both the seismic force coefficient and the soil characteristics are regarded as random quantities; then,based on the upper bound method and the strength reduction method,the stability performance function of thestepped slope considering the seismic force effect is derived; since the equation expression is an implicit function,the approximate explicit expression of the original function is obtained by the random response surface method; finally,the approximate explicit functionis simulated by Monte Carlo method, andthe failure probability of the slopeis obtained. The analysis of a given engineering example shows thatthe accuracyof this method is equivalent to the traditional Monte Carlo method,but the calculation process is relatively simple and efficient,and can be effectively applied to the stability analysis of stepped slopes.
引文
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[12]蒋建平,罗国煜,高广运.粘性土变形和强度参数分析[J].交通运输工程学报,2007,7(6):76-79.
[13]陈洪江,张兴洲,王春海.基于强度折减法的黄土边坡稳定性方差分析[J].交通科学与工程,2016,32(3):7-11.
[14]揭兴政.极限分析和Monte-Carlo方法相结合的路基边坡的局部可靠度和加固效果研究[J].湖南交通科技,2016,42(2):10-13,62.
[2]杨和平.极限平衡法与有限元强度折减法对某公路边坡挡土墙稳定性分析[J].公路工程,2012,37(3):180-183.
[3] Drucker D C,Prager W. Soil mechanics and plastic analysis or limit design[J]. Q. appl. math,1952,10(2):157-65.
[4]殷宗泽,吕擎峰.圆弧滑动有限元土坡稳定分析[J].岩土力学,2005,26(10):1525-1529.
[5]高德彬,倪万魁,梁伟.基于Monte-Carlo模拟的公路黄土高边坡可靠性研究[J].公路交通技,2005,22(9):66-68.
[6]王建华,易朋莹,何江海,等.运用一次二阶矩法分析滑坡稳定可靠度[J].工程地质学报,2006(S1):138-142.
[7]李典庆,周创兵,陈益峰,等.边坡可靠度分析的随机响应面法及程序实现[J].岩石力学与工程学报,2010,29(8):1513-1523.
[8]蒋水华,祁小辉,曹子君,等.基于随机响应面法的边坡系统可靠度分析[J].岩土力学,2015,36(3):809-818.
[9]陈惠发.极限分析与土体塑性[M].北京:人民交通出版社,1995.
[10] Ditlevsen O D,Madsen H O. Structural Reliability Methods[J].2005.
[11]刘德贺,史玉峰.基于TLS技术的道路边坡地表位移监测研究[J].森林工程,2018,34(2):95-99.
[12]蒋建平,罗国煜,高广运.粘性土变形和强度参数分析[J].交通运输工程学报,2007,7(6):76-79.
[13]陈洪江,张兴洲,王春海.基于强度折减法的黄土边坡稳定性方差分析[J].交通科学与工程,2016,32(3):7-11.
[14]揭兴政.极限分析和Monte-Carlo方法相结合的路基边坡的局部可靠度和加固效果研究[J].湖南交通科技,2016,42(2):10-13,62.