土工格室-碎石桩双向增强复合地基大比例室内模型试验  

Large Scale Laboratory Experiments on Two-directional Composite Foundation Reinforced with Geocell and Stone Columns

作　　者：张玲[1] 赵明华[1] 马缤辉[1] 雷勇[1] 邓岳保[1] 

机构地区：[1]湖南大学岩土工程研究所,湖南长沙410082

出　　处：《中国公路学报》2013年第6期1-8,共8页China Journal of Highway and Transport

基　　金：国家高技术研究发展计划("八六三"计划)项目(2006AA11Z104);国家自然科学基金项目(51078138);湖南大学青年教师成长计划项目

摘　　要：为分析不同地基对其加固后的路基竖向承载力和竖向变形的影响,设计并完成了单纯软基、土工格室加筋地基、碎石桩复合地基和土工格室-碎石桩复合地基4组大比例室内模型试验,分析了经格室加筋垫层、碎石桩和土工格室-碎石桩加固后的路基竖向承载力和竖向变形变化规律。结果表明:经土工格室-碎石桩双向增强复合地基处治后的路基承载力大于单一碎石桩复合地基和单一土工格室加筋地基;土工格室加筋垫层具有良好的筏板和应力均化作用,从而使碎石桩桩顶沉降量明显减小,加筋垫层对路堤荷载下桩端沉降的影响不大;路堤荷载下,碎石桩桩顶沉降量小于同平面桩间土沉降量,大于桩端沉降量,以致路堤荷载下复合地基中桩间土先于桩体发生破坏。Four large scale laboratory experiments on the untreated soft soil, geocell reinforced subgrade, composite foundation reinforced with stone columns, and composite foundation reinforced with geocell and stone columns were conducted to study the effects of different foundations on the vertical bearing capacity and deformation of the subgrade. The vertical bearing capacity and deformation of the subgrade reinforced respectively with geocell, stone columns, and combination of geocell and stone columns were analyzed. The results indicate that the bearing capacity of the subgrade reinforced simultaneously with geocell and stone columns is much larger than that reinforced only with geoeell or that reinforced only with stone columns. The geocell reinforced mattress has a significant reduction effect on the column top settlement due to its stress dispersion effect, but has a little effect on the column tip settlement. The results also indicate that the column top settlement is less than the settlement of the surrounding soil at the top plan, but it is larger than the column tip settlement under embankment foundation, so the soil will be yielded earlier than the column under embankment foundation.

关 键 词：道路工程 双向增强复合地基 大比例室内模型试验 土工格室 碎石桩 

分 类 号：U416.03[交通运输工程—道路与铁道工程]