基于非平稳随机场的水泥土堤坝边坡可靠度分析  

Reliability analysis of embankment slope in cement-mixed soil with non-stationary random field

作　　者：杨亮 刘辉 章荣军[1] 郑俊杰[1] YANG Liang;LIU Hui;ZHANG Rongjun;ZHENG Junjie(Institute of Geotechnical and Underground Engineering, Huazhong University of Science and Technology, Wuhan 400074, P. R. China)

机构地区：[1]华中科技大学岩土与地下工程研究所,武汉430074

出　　处：《土木与环境工程学报（中英文）》2022年第5期78-86,共9页Journal of Civil and Environmental Engineering

基　　金：国家自然科学基金(51978303)。

摘　　要：采用水泥固化疏浚淤泥作为堤坝填料往往会使堤坝土体参数具有较高的变异性;同时,在水泥土堤坝填筑过程中,通常设置水平排水板加速土体排水固结,这使得主固结完成后水泥土强度随排水板位置呈现一定空间变化趋势,通常的平稳或准平稳随机场模型很难表征这一趋势。为此,提出一种不排水抗剪强度垂直排水板方向衰减的非平稳随机场模型,并以水泥土堤坝边坡为例,结合强度折减法和蒙特卡洛模拟,对比提出的非平稳随机场模型和传统平稳随机场模型、深度趋势非平稳随机场模型对边坡安全系数和滑动面分布的影响,讨论模型中趋势参数对可靠度的影响。结果表明:平稳随机场模型及深度趋势非平稳随机场模型的计算结果偏于危险,提出的非平稳随机场模型既能考虑土体不排水抗剪强度沿深度方向的趋势项与随机波动项,又能考虑其沿垂直排水板方向的衰减趋势,与现有研究符合较好。The soil properties of embankment slope filled with cement solidified dredged sludge commonly feature high variability.Meanwhile,in construction process of cement-mixed embankment,horizontal drainage plate is generally used to accelerate the consolidation of cement-mixed soil,which makes the soil strength show a spatial distribution trend at the vertical direction(perpendicular to the drainage plate)after the primary consolidation finished.The traditional stationary or quasi-stationary random field model cannot well characterize this trend.This paper proposes a non-stationary model to characterize the attenuation trend of soil strength along the normal direction of drainage plate.The strength reduction method and Monte Carlo simulation are combined to evaluate the reliability of slope,and the proposed model is compared with two existing models(i.e.,traditional stationary random field model and depth trend non-stationary random model).The influence of different random filed models on safety factor and slip surface are investigated,and the impact of trend parameters in the proposed model on slope reliability are discussed.The results show that the stationary random field model and depth trend non-stationary random field model may overestimate the reliability of embankment slope,and the proposed non-stationary random field model can consider both the trend term and random fluctuation term in vertical direction and the attenuation trend in normal direction of drainage plate,which is in good agreement with the existing research.

关 键 词：非平稳随机场 水泥土边坡 可靠度分析 不排水抗剪强度 堤坝 

分 类 号：TU457[建筑科学—岩土工程]