被动桩计算模式及考虑土拱效应的计算方法

Computation Module of Passive Piles and Its Practical Calculation Method by Considering Soil Arching Effect

建立了地面堆载条件下对邻近桩基影响的实用计算模式,将被动桩分为受土体位移作用的被动部分和受土体抗力作用的主动部分分别考虑,以Itos土压力为依据,考虑土体的实际分层和被动区侧移土体成拱效应,计算被动部分桩侧土压力,主动侧作用于桩身上的土体抗力与桩的变形成正比.通过桩的平衡建立位移协调方程,采用有限差分法求解建立的微分方程,并编制了VBA电子表格有限差分程序.最后通过一个工程实例对所提出的被动桩实用计算方法进行了验证.

Computation model is set up to analyse passive piles subjected to adjacent surcharge loads. In the computation model passive piles are divided into passive parts subjected to soil deformation induced by adjacent surcharge loads and active parts resulting from the above passive loads. Passive parts of passive piles are calculated according to Itos soil pressure theory, with a consideration of the layered soil and arching effect of lateral displacement soil in passive parts. Active parts of passive piles are calculated according to traditional limiting force profile method. The bending moment and deformation of passive piles are solved on the basis of the displacement compatibility differential equation by finite difference method. Program solving the above finite difference equation is developed by Excel VBA. Finally the practical calculation method is verified by an engineering example.