土工合成材料处治老路路基拓宽的数值分析

NUMERICAL ANALYSIS OF GEOSYNTHETICS TREATMENT IN OLD ROAD WIDENING

随着交通量的日益增加,老路拓宽已经成为公路建设非常重要的一种手段。为减少老路拓宽新老路基不均匀沉降,提高路基整体稳定性,土工合成材料在新老路基结合部处治中获得很大的成功。针对老路拓宽时采用土工合成材料处治结合部的特点,将新老路基、路面结构作为整体,建立数值模型。采用FLAC进行分析,主要从路基位移、路基顶面应力及土工合成材料拉力分布等方面,研究土工合成材料处治新老路基结合部的作用机制,分析不同加筋层数和不同路基填土高度下的处治效果。计算结果表明,采用土工合成材料不仅可以有效地减小路基顶面的差异沉降和水平位移,而且使得路基反射到路面的平均应力更小且分布均匀。

With the traffic increase, old road widening is found to be an important issue in the road construction. In order to reduce the different settlement and improve the stability of the embankment, the geosynthetics have been successfully adopted in the joint between the old and new embankments. Based on the features of the geosyntheticsreinforced old road widening, the old and new embankments and the pavement are regarded as a whole structure; and the numerical model is performed on the basis of the assumption. Adopting the FLAC, the mechanism of geosynthetics-reinforced old road widening is discussed mainly from three factors as follows： （1） the displacements of embankment; （2） the stress distributions on the crest of embankment; and （3） the tensions developed in geosynthetics. In addition, the different effects under the different layer numbers of geosynthetics and heights of embankments are studied. The results show that using geosynthetics in the reinforcement of embankment is effective not only in reducing the differential settlements and horizontal displacements on the crest of the embankments, but also in uniform stress distribution that is reflected from embankment to the pavement.