饱和块状混合回填土地基的一维固结分析  

One-dimensional consolidation analysis of saturated lumpy composite backfill foundation

作　　者：胡亚元[1] 周焕慧 HU Ya-yuan;ZHOU Huan-hui(Research Center of Coastal and Urban Geotechnical Engineering,Zhejiang University,Hangzhou 310058,China)

机构地区：[1]浙江大学滨海和城市岩土工程研究中心,浙江杭州310058

出　　处：《岩土工程学报》2022年第4期632-642,共11页Chinese Journal of Geotechnical Engineering

基　　金：国家自然科学基金项目(52178360)。

摘　　要：用块状渣土置换软弱地基和回填低洼谷地等是处置工程渣土的有效途径。为了分析饱和块状混合回填土地基的固结性状,运用混合物理论建立了其一维固结模型。首先,假定块状土固相和充填土固相之间满足等应变条件,获得了饱和块状混合回填土中各相应变与块状土孔隙变形和充填土孔隙变形的关系式。其次,在小应变条件下,根据自由能势函数方程建立了饱和块状混合回填土的一维线弹性本构方程,再结合达西定律和应力平衡方程获得了一维固结控制方程。再次,利用分离变量法得到一维固结解析解,通过退化本文模型与已有模型进行对比,验证了本文模型的正确性。最后,基于所得解析解,分析了充填土孔隙渗透系数、块状土孔隙渗透系数以及流体交换参数等因素对饱和块状混合回填土地基固结性状的影响。分析结果表明:充填土孔隙渗透系数对饱和块状混合回填土地基整体固结性状起主导作用;在固结初期,块状土超孔压会有一定程度的上升,且3个参数具有相似的作用机理。It is an effective way to replace the soft foundation waste and backfill the low-lying valley with the lumpy waste. In order to explore the consolidation behaviors of saturated lumpy composite backfill foundation, one-dimensional(1-D)consolidation model is established by using the mixture theory. Firstly, based on the assumption of the equal solid strain condition between lumpy soil and filling soil, the formulations are obtained between each constituent strain and pore deformations in lumpy soil and filling soil. Then, under small strain, the 1-D linear elastic constitutive equations for the saturated lumpy composite backfill soil are derived by applying the free energy potential constitutive equations, and the governing equation for 1-D consolidation is provided based on the Darcy’s law and the stress equilibrium equation. Meanwhile,its analytical solution is gained by using the separation variable method, and the contrast between the degenerating model and other existing ones shows the validity of the proposed model. Finally, the influences of two pore permeability coefficients and fluid exchange parameter on the characteristics of 1-D consolidation for the saturated lumpy composite backfill foundation are studied by adopting the analytical solution. The analysis results indicate that the permeability coefficient in filling soil plays a leading role in the consolidation behaviors, and the pore pressure in the lumpy soil increases to a certain extent at the initial stage of consolidation and three parameters have the similar mechanism.

关 键 词：工程渣土 饱和双重孔隙介质 混合物理论 一维固结 解析解 

分 类 号：TU433[建筑科学—岩土工程]