摘要
青藏铁路和青藏公路沿线的斜坡稳定对交通线路的安全运营十分重要,与其稳定性评价有关的土的参数指标样本很少,且离散性很大,很难得到较为准确的统计特性,针对此问题,该文基于区间理论,提出了一种小样本条件下多年冻土地区斜坡稳定问题的可靠性分析方法。主要考虑斜坡的热融滑塌,采用无限边坡稳定分析理论,给出了功能函数表达式,将不确定变量视为边界变化的区间变量,区间的下界和上界分别为采样数据的最小值和最大值,用功能函数的中值与离差之比η来估计斜坡稳定的可靠性,η将随样本数量发生变化。为了估计η和概率可靠指标β的关系,将不确定变量视为随机变量,给出了β和η比值的区间估计表达式,并采用上述方法分析了青藏铁路K3035处冻土斜坡稳定的可靠性。
The stability of slopes along Qinghai-Tibet Railway and Highway is very important to their normal operations. The soil properties related to its analysis uasuUy have a high degree of uncertainty, and it is difficult to obtain sufficient statistical data to evaluate their variability. In this paper, based on Interval Theory, a new reliability analysis method of slope stability in permafrost regions with small sample size is proposed. The thaw slump of slopes is considered, and the performance function is given using the theory of infinite slope stability analysis. The uncertain variables are viewed as interval variables with variable bounds, and the upper bounds and lower bounds are the maximum value and the minimum value of sampling data, respectively. The ratio of the central value of the performance function to its dispersion is used as an index to assess the reliablity of slope stability. The index changes with the number of samples. In order to find out the relationship between the index and the probability reliability index, the uncertain variables are treated as random variables, and the formulation to calculate the interval of the ratio of the two indexes is given. The proposed method is used to estimate the reliability of a slope stability along Qinghai-Tibet Railway.
出处
《工程力学》
EI
CSCD
北大核心
2008年第7期166-171,共6页
Engineering Mechanics
基金
教育部新世纪优秀人才计划项目(NCET-05-0092)
科技部支撑计划项目(2006BAC07B02)
国家自然科学基金项目(50678020)
关键词
可靠性分析
斜坡稳定
热融滑塌
小样本
多年冻土
reliability analysis
slope stability
thaw slump
small sample size
permafrost
