二灰土改良含高富水土层公路路基的数值模拟  

Numerical Simulation for Modifying Highway Roadbed Contenting High Rich-water Soil Layer by Lime Flyash

作　　者：牟其海[1] 李帅[2] 张爽[2] 

机构地区：[1]沈阳市市政工程设计研究院,辽宁沈阳110819 [2]东北大学资源与土木工程学院,辽宁沈阳110819

出　　处：《城市道桥与防洪》2014年第2期143-148,14,共6页Urban Roads Bridges & Flood Control

摘　　要：由于利用粉煤灰、石灰做填料来改良土壤具有很多优点,因此,二灰法改良土成为土质改良的重要方法。针对广西公路DK116+100标段高富水土层的水文地质特征,采用多物理场耦合分析软件Comsol Multiphysics,基于比奥固结理论,建立了考虑孔隙率受土骨架变形影响,及流体压力和路基受车辆荷载共同作用均质饱和多孔介质动态变形过程的二维渗流-应力耦合模型。通过对比二灰土改良路基和一般路基数值模拟结果,研究表明:经过二灰土改良后的高富水砂层公路路基比一般没有处理的高富水砂层公路路基路面沉降显著减少,土层水压增加缓慢,靠近路堤基底附近的砂土层及承受车辆荷载的路面处产生的拉应力区域减小,路堤坡脚处的压应力区域也明显减小。Because of the many advantages of using the lime and flyash as the stuffing to modify the soil, the lime-flyash method is important method to modify the soil quality. Aiming at the hydrogeology of high rich-water soil layer in the highway DK116+100 of Guangxi, making use of the multiphysics coupled analysis software Comsol Multiphysics, based on the Biot's consolidation theory and taking into account the effects on porosity with deformation of soil skeleton, a two-dimensional seepage-stress coupled model is established describing process of ground dynamic deformation refined due to working together by fluid pressure and car load. By contrasting the numerical simulation between the modified roadbed by lime-flyash method and the general roadbed, the results indicate that pavement settlement of modified roadbed by lime-flyash obviously decreases in contrast to the general roadbed without the treatment, the water pressure of soil layer increases slowly, the tensile stress zone near the bottom of embankment in sand bed and the pavement taking vehicles decreases, and the compressive stress zone near slope toe of embankment also observably decreases.

关 键 词：二灰土 高富水土层 路面沉降 公路路基 数值模拟 

分 类 号：U416.1[交通运输工程—道路与铁道工程]