考虑上部荷载影响区的筏板抗浮锚杆布置方法研究

Reasonable layout of anti-floating anchors of basement raft considering the upper load affected area

由于地下水浮力及上部荷载对地下结构筏板的作用方式不同,将抗浮锚杆满堂均布于底板的方式会使各锚杆受力不均匀,本文以单建式筏板基础的二层地下结构为模拟研究对象,利用有限元法建立数值计算分析模型,对底板厚度、柱轴力、地下水头等因素影响板底土反力进行计算,由此分析了柱下板底的上部荷载影响区的主要特征;在柱跨板块下采取满堂均布、上部荷载影响区以外非均布等四种方式布置锚杆条件下,对锚杆受力变异系数和筏板变形进行了计算比较,表明在上部荷载影响区外非均布锚杆的工作性能更好。本文分析方法和对锚杆布置方式的分析结论,可供工程设计参考。

Due to the different ways of groundwater buoyancy and upper load acting on the rafts of underground structures,the way that anti-floating anchors are distributed all over the floor will make the anchors unevenly loaded.In this paper,a two-story underground structure with raft foundation is analyzed by using the finite element method(FEM).The influences of factors such as raft thickness,column axial force,groundwater head and other factors on the bottom soil reaction are calculated by the FEM model and the main characteristics of the upper load influence area on the raft under the column are analyzed;Four different ways including the anchors are a uniformly distributed throughout the raft bottom and non-uniformly distributed outside the.upper load affected area under columns are considered respectively.By comparing the results of variation coefficients of the force on'the anchors and the deformations of the raft under the four different distribution ways of anchors,it can be shown that non-uniformly distributed anchors outside the upper load affected area work better.The analysis methods and conclusions on the layout of anchors in.this paper can be used as references for engineering design.