土质斜坡地层倾斜锚板抗拔承载力分析

Analysis of Uplift Bearing Capacity of Inclined Anchor Plate in Soil Slope

研究目的:合理估算锚板抗拔承载力是保持锚板基础稳定工作的重要保障,本文聚焦土质斜坡地层中埋设的倾斜条形锚板,构造了一种极限状态下非对称的锚板上拔破坏机制,并假设土体破坏服从非线性强度准则与非关联流动法则。基于该破坏机制,利用上限法与变分原理,推导锚板极限抗拔承载力及锚板上方土体破坏面方程的解析表达式,系统研究各参数对锚板抗拔承载力的影响规律。研究结论:(1)推导得到了锚板极限抗拔承载力及锚板上方土体破坏面方程的解析表达式,并与现有文献成果进行了对比分析,验证了本文分析方法的有效性;(2)斜坡倾斜锚板上方土体破坏范围呈现一定的非对称特征,随锚板倾角增大,土体破坏范围逐渐向坡下方向偏移,土体破坏范围与土体剪胀系数、初始黏聚力正相关,与非线性系数、重度、地表荷载负相关;(3)锚板埋深比、埋设角度、地表倾角、土体黏聚力及剪胀系数对锚板抗拔承载力及土体上拔破坏范围会产生显著影响,在工程设计中应予以重视,以实现锚板基础的最优布设与承载能力有效发挥。

Research purposes:A reasonable estimation of anchor plate's pulling capacity is an important guarantee to maintain the stability of anchor plate foundation.This paper focused on the inclined strip anchor plate buried in the soil slope stratum,constructed an asymmetric pulling failure mechanism of anchor plate under the limit state,and assumed that the soil failure hypothesis follows the nonlinear strength criterion and its non-correlated flow law.Based on the failure mechanism,the analytical expressions of the ultimate pulling capacity of anchor plate and the failure surface equation of soil above the anchor plate were derived by using the upper limit method and variational principle,and the influence of each parameter on the pulling capacity of anchor plate was systematically studied.Research conclusions:(1)The analytical expressions of the ultimate uplift bearing capacity of the anchor plate and the failure surface equation of the soil above the anchor plate were derived,and the effectiveness of the analysis method was verified by comparison with the existing literature results.(2)The failure range of soil above the inclined anchor plate presents a certain asymmetric feature.As the angle of anchor plate increases,the failure range of soil gradually shifts to the downward slope.Soil failure range is positively correlated with soil dilatancy coefficient and initial cohesion,and negatively correlated with nonlinear coefficient,unit weight and surface load.(3)The embedment depth ratio of anchor plate,embedment angle,surface inclination angle,soil cohesion and dilatancy coefficient have significant effects on the uplift bearing capacity of anchor plate and the uplift failure range of soil,which should be paid attention to in engineering design to realize the optimal layout of anchor plate foundation and the effective use of bearing capacity.