土工格栅处治填挖交界路基数值模拟与现场试验

考虑地基与路基的压缩变形与填挖交界处的相互作用,应用分析软件ANSYS建立了路基变形有限元模型,模拟了格栅竖向间距与挖方段铺设长度对土工格栅加筋纵向处治填挖交界路基的影响规律,并通过现场修筑不同方案的试验路段和沉降跟踪观测,研究了土工格栅铺设层数对填挖交界路基差异沉降的影响。分析结果表明:土工格栅的竖向铺设间距在0·8~1·0m时,路基不均匀沉降较小,路面产生竖向位移的变化较缓慢,建议土工格栅铺设的竖向间距以不大于1·0m为宜;改变锚固端格栅铺设长度对路面竖向沉降的影响很小,从经济角度考虑,挖方段土工格栅的最小锚固长度选取2m;在路基96区和94区底各铺设一层土工格栅可以有效降低路基差异沉降。

Numerical simulation and field test at the cut to fill location of subgrade treated with geogrids

The compression deformations and interaction of the subgrade and groundsill were considered at the cut to fill location, a finite element model of subgrade deformation was established by using ANSYS software, the influence rules of the vertical space and length of geogrids at cut location on subgrade were simulated, the field test and subsidence track observation at different test sections were carried out, and the influence of geogrids layer number on the unequal settlement of subgrade was studied. The result indicates that when the vertical space of geogrids is 0.8~1.0 m, the change of vertical displacement for pavement is slower, the unequal settlement of subgrade is less, so it is recommended that the rational vertical space of geogrids is not bigger than 1.0 m; the smallest chose length of geogrids at reinforcing end in cut section is 2 m for economy because the influence of the length change on the vertical displacement of pavement is less; the unequal settlement of subgrade can be reduced effectively by burying a layer of geogrid at the bottom of 96 area and 94 area respectively. 5 tabs, 6 figs, 15 refs.