不排水桩复合地基非线性固结解析解

考虑桩土模量比随固结而不断变化,在等应变条件下,通过理论推导,得到了适用于不排水桩复合地基的非线性固结解析解,并进行了地基固结性状分析。结果表明:土体压缩指数与渗透指数比值越小,地基固结越快,当比值等于1时,地基非线性固结解与线性固结解不相等,而是非线性固结度始终小于线性固结解;另一方面,考虑桩土模量比随固结变化情况下地基固结比假设桩土模量比不变情况下固结要慢,并且压缩指数与渗透指数比值越大,桩土初始模量比越大,两者差距越大。因此,对不排水桩复合地基,假设桩土模量比不变高估了地基的固结度,对工程安全不利。

Nonlinear Analytical Solution for Consolidation of Composite Foundation Reinforced by Impervious Column

Considering the variation of the ratio of compression modulus of pile and soil with consolidation,the nonlinear analytical solution for consolidation of impervious column reinforced composite foundation was obtained under the condition of equal strain,and the consolidation behavior of foundation was analyzed.The results show that the smaller the ratios of compression index to permeability index,the faster the foundation consolidation.Under the condition that the ratio of compression index to permeability is equal to 1,the nonlinear consolidation solution is not the same as linear consolidation solutions,but the nonlinear consolidation degree is always smaller than the linear consolidation solution.On the other hand,the results also show that the nonlinear consolidation rate deduced form the present solution is slower than the solution under the condition that the modulus ratio of pile and soil is constant,and the bigger the ratio of compression index to permeability index,the bigger the initial modulus ratio of pile to soil,the bigger the difference between them.In other words,for composite foundation reinforced by impervious column,ignoring the variation of the modulus ratio of pile to soil will overtake the consolidation rate of the foundation,which is disadvantageous to safety of engineering.