高速公路工程中水泥搅拌桩桩身合理设计强度研究

在公路工程的搅拌桩地基设计中,一般假设加固区桩土变形协调,从而采用复合地基理论进行设计。但是目前许多的工程实践表明在路堤荷载作用下,搅拌桩地基桩土之间存在差异沉降,桩身强度不能够完全发挥,为此需要对复合模量的表达式进行改进。本文采用有限元分析了路堤荷载作用下搅拌桩地基的变形响应情况,分析了加固区桩间土变形与桩身模量之间关系,得到了水泥土搅拌桩强度的合理范围。

FINITE ELEMENT ANALYSIS FOR OPTIMAL DESIGN OF DEEP MIXED COLUMN FOUNDATION IN HIGHWAY EMBANKMENTS

Composite foundation theories,based on an equal-strain concept between soil and columns in the reinforced area,is commonly used in China to design deep mixed column(DMC) foundations.However,many case studies show that differential deformations between soil and columns in the reinforced area are obvious under the loading of highway embankments.The strength of DMCs can not be fully mobilized.The composite modulus of the reinforced area should be modified for the calculation of differential deformations.Finite element method(FEM) is used in this study to investigate the behavior of DMC foundations under the embankment loading,and a reasonable strength range of DMCs is put forward.Finally a method is proposed to reasonably estimate the modified composite modulus of the reinforced area by considering the degree of mobilization of DMCs.