Differential settlement characteristics and influencing factors of widening subgrade
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摘要: 为了解差异沉降对拓宽道路的影响, 应用有限元程序, 建立了差异沉降计算模型, 分析了拓宽路基差异沉降特性, 研究了路基高度、土基压缩模量、拓宽方式和宽度对路基差异沉降以及沉降曲线形态的影响。结果表明, 双侧拼接在差异沉降控制上优于单侧拼接; 土基压缩模量从2MPa增加到10MPa时, 最大差异沉降从20.58cm降低到5.46cm, 且最大差异沉降的增加和土基压缩模量的减小不成反比例, 存在减速性; 当路基高度从2m增加到8m时, 最大差异沉降从6.38cm增加到13.10cm, 受边界条件的影响, 路基高度越小, 拓宽路基顶面沉降曲线越接近“~”形。Abstract: In order to know the influence of differential settlement on widening subgrade, the differential settlement characteristics of widening subgrade were analyzed by finite element method, and the influences of subgrade height, compressive modulus, widening mode and width on the differential settlement and settlement curves of subgrade were studied. The result shows that differential settlement controlling on widening road with two sides is better than that with one side, the maximum differential settlement decreases from 20.58 cm to 5.46 cm when compressive modulus increases from 2 MPa to 10 MPa, and the increase of the biggest differential settlement is not in inverse proportion to the decrease of compressive modulus, while presents slowdown trend; the biggest differential settlement increases from 6.38 cm to 13.10 cm with subgrade height increasing from 2 m to 8 m, because of the influence of boundary conditions, the smaller the subgrade height is, the closer the settlement curve of widening subgrade top is to "~".
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表 1 计算参数
Table 1. Calculation parameters
类别 密度/(kg·m-3) 压缩模量/MPa 泊松比 摩擦角/(°) 粘聚力/kPa 旧路基 1 800 50 0.35 25 25 新路基 1 800 40 0.35 25 25 旧土基 1 800 15 0.35 20 25 新土基 1 800 4 0.35 15 25 -
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