基于随机场理论的临坡地基承载力及破坏模式研究  

Research on the Bearing Capacity and Failure Mode of Slope-adjacent Foundations Based on Random Field Theory

作　　者：周炳 卢波 方鸿 张映星 祝玉波 ZHOU Bing;LU Bo;FANG Hong;ZHANG Yingxing;ZHU Yubo(Hunan Road and Bridge Construction Group Co.,Ltd.,Changsha,Hunan 410018,China;Hunan Communications Research Institute Co.,Ltd.,Changsha,Hunan 410114,China)

机构地区：[1]湖南路桥建设集团有限责任公司,湖南长沙410018 [2]湖南省交通科学研究院有限公司,湖南长沙410114

出　　处：《公路工程》2025年第1期153-160,170,共9页Highway Engineering

基　　金：湖南省交通科技项目(202238)。

摘　　要：临坡地基受不对称应力场和土性参数空间变异性的影响,其承载力与水平地基有较大差别,并且难以准确分析临坡地基的破坏模式。基于随机场理论对空间土体进行离散,以模拟土体不排水抗剪强度的空间变异性,建立了随机自适应有限元极限分析法数值模型,据此开展确定性和不确定性分析,主要探讨了坡度、承载力系数、稳定系数、距离系数、土体自相关距离对临坡地基承载力及破坏模式影响。研究表明,随坡度和距坡肩的水平距离增加,临坡地基逐渐由坡面剪切模式转变为坡角剪切模式,当距坡肩较远距离时出现普朗特尔模式;随着稳定系数增大,坡度较小的临坡地基呈现出坡底剪切模式,而坡度较大时临坡地基剪切带由基础边缘后一定距离处发育至坡脚,并且由坡面剪切模式转变为整体破坏模式;当坡度由15°增加至60°,临坡地基承载力显著减小,破坏模式由坡面剪切破坏逐渐向整体稳定性破坏过渡;坡度和土体强度分布模式共同作用影响临坡地基破坏模式;当出现普朗特尔剪切破坏模式时,坡度对临坡地基破坏模式影响已不明显,其表现与平坦地基破坏模式接近;土体自相关距离对临坡地基极限承载力影响较大,而对于边坡的剪切模式的影响较小。The bearing capacity of a slope-adjacent foundations differs significantly from that of a horizontal foundation due to the influence of asymmetric stress fields and spatial variability in soil property parameters,making it difficult to accurately analyze the failure mode of slope-adjacent foundations.Based on the random field theory,the spatial soil mass is discretized to simulate the spatial variability of soil's undrained shear strength.A numerical model of stochastic adaptive finite element limit analysis is established for deterministic and uncertainty analyses.This paper mainly discusses the impacts of slope angle,bearing capacity factor,stability factor,distance factor,and soil autocorrelation distance on the bearing capacity and failure mode of slope-adjacent foundations.The research shows that as the slope angle and horizontal distance from the slope shoulder increase,the failure mode of slope-adjacent foundations gradually shifts from slope-surface shear failure to slope-toe shear failure,when the distance from the slope shoulder is relatively long,the Prandtl mode appears;as the stability factor increases,slope-adjacent foundations with smaller slope angles exhibit slope-base shear failure,while those with steeper slopes show shear zones developing from a certain distance behind the foundation edge to the slope toe,transitioning from slope-surface shear failure to overall failure.When the slope angle increases from 15°to 60°,the bearing capacity of slope-adjacent foundations decreases significantly,and the failure mode transitions from slope-surface shear failure to overall stability failure.The failure mode of slope-adjacent foundations is jointly influenced by the slope angle and soil strength distribution pattern.When Prandtl's shear failure mode occurs,the influence of the slope angle on the failure mode of slope-adjacent foundations becomes insignificant,resembling the failure mode of flat foundations.The autocorrelation distance of soil has a significant impact on the ultimate bearing capacity o

关 键 词：边坡工程 临坡地基 随机场理论 地基承载力 破坏模式 

分 类 号：U416.14[交通运输工程—道路与铁道工程]