泡沫混凝土拓宽路基的差异沉降研究

A study of the differential settlement of subgrade widen with foam concrete

在分析泡沫混凝土用于高速公路路基拓宽模式的基础上,建立了泡沫混凝土拓宽路基的附加应力计算模型;推导了新老路基差异沉降计算公式,并结合绍(兴)诸(暨)高速上三段拓宽工程的建设,分析了泡沫混凝土拓宽路基的地基附加应力分布规律和沉降特性以及拓宽参数对新老路基不均匀沉降的影响。研究表明,随拓宽宽度增加,老路受影响范围越大,不均匀沉降增大,最大差异沉降率非线性增大;零征地拓宽时,拓宽对老路沉降基本没有影响;随开挖宽度增加,泡沫混凝土的"应力置换"效果增强,路基的不均匀沉降减小,最大差异沉降率减小。

Based on the analysis of the pattern of foam concrete used in freeway widening project,the additional stress calculation model of foam concrete widening subgrade is established,and the formula for calculating differential settlement of freeway widening project is developed.Combined with the highway widening project of the Shangsan Expressway,the distribution law of additional stress,the features of differential settlement of freeway widening project and the influence of broaden parameters to it are analyzed.The results show that,with the increasing broadening width,the affected area of old subgrade increases,the uneven settlement increases,and the maximum rate of differential settlement increases non-linearly.The zero land acquisition to broaden has little effect on old subgrade.With the increasing width of excavation,the effect of ＂stress displacement＂ derived from the difference of embankment fill increases,the differential settlement of the subgrade reduces,and the maximum different sedimentation rate decreases.