斜坡地形输电线路临坡基础抗拔承载特性分析

Analysis of uplift bearing capacity for slope crest foundation of power transmission line in slopes terrain

  • 摘要: 临坡基础是输电线路通过斜坡地形时所采用的一种常见的基础形式,其抗拔承载特性研 究在国内尚处于起步阶段。本文基于平地条件下安徽太湖现场试验的结果,利用 FLAC 3D对该地 区岩体力学参数进行参数反演。采用反演所得参数,按不同坡顶距、基础埋深、坡角设计完成了18组共计138个临坡基础的抗拔承载数值模拟计算。通过对比分析模拟结果中的垂直向、水平 向位移云图及塑性区分布图,将临坡基础的破坏模式总结为浅埋模式与深埋模式两种。同时,以 临坡基础极限抗拔荷载衰减率为分析基准,得出临坡基础抗拔承载性能随坡顶距及基础埋深的 增加而提高,随坡角的增大而降低的规律,并提出临坡基础最小安全坡顶距的概念,为输电线路 临坡基础的设计与施工提供科学的依据与参考。

     

    Abstract: Abstract:The slope crest foundation is a common type of foundation which is often used in power transmission line through the slopes terrain , the study on the uplift bearing capacity of this foundation is still at the initial stage in China.Firstly , the parameter inversion of rock mass mechanics parameters were inversed by FLAC " based on the results of in-situ test on the flat ground in Anhui.Secondly, 138 numerical simulations of slope crest foundation were calculated according to the different distances between slope shoulder and foundation edge , foundation depths and slope angles by using the inversion parameters.And it is concluded that the failure modes of the slope crest foundation can be divided into the shallow buried mode and the deep buried mode by comparing the vertical and horizontal displacement nephogram and the plastic zone distribution of the simulation results.Meanwhile , based on the analysis of the decay rate of ultimate uplift load, it is summarized that the uplift bearing capacity of slope crest foundation increased with the increase of the distance between slope shoulder and foundation edge and foundation depth , but decreased with the increase of slope angle.The concept of minimum safe top distance of slope foundation is proposed to provide scientific basis and reference for design and construction of transmission line slope foundation.

     

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