组合型复合地基固结分析

Consolidation of combined composite foundation

水泥搅拌桩和塑料排水板联合使用的组合型复合地基具有利用搅拌桩增强软土地基的强度,利用塑料排水板加快地基的固结进程的特点,因此对于处理深厚饱和软土地基具有很强的推广价值。由于其平面布置多为梅花形,整体上呈非对称性,其固结特性理论分析的难度较大。为了从理论上进行该组合型复合地基固结特性分析,本文首先针对其排水系统进行了合理的简化,根据固结分析模型建立了桩–板组合型复合地基的固结微分方程,并利用边界条件获得了该组合型复合地基固结分析的解析解;其次通过三维有限元计算结果和解析解的对比分析验证了该解析解的合理性和可行性;最后针对置换率、压缩模量和加固深度等影响因素的分析,探讨了该组合型复合地基的固结特性,为实际工程的应用提供理论指导。

The combined composite foundation with cement-mixing piles and prefabricated vertical drain has the characteristics of enhancing the strength of soft soil through soil-cement piles and promoting the consolidation process of foundation through drainage system.Therefore,it has high promotion value for dealing with deep saturated soft soil.The distribution of piles and vertical drain in this method is usually in equilateral triangle pattern.Due to its unsymmetrical distribution in plane,it is not easy to get the typical model for the theoretical consolidation analysis.To develop the consolidation analysis of this combined composite foundation,at first the drainage system is reasonably simplified.And then a consolidation equation is established from the model,and its solution is acquired on the basis of the boundary conditions.The analytical solution is verified to be reasonable and feasible through the comparison with the results of 3D finite element method.The main influencing factors such as replacement ratio,modulus,and depth are explored to get the characteristics of its consolidation,which can be beneficial to guide the actual engineering.