采用深层混凝土搭板处治桥头跳车的试验

Case study of the deep-seated concrete slab for settlement control at bridge approach embankment

为了解决传统近路面桥头搭板受车辆荷载的冲击作用,加之下方发生脱空现象,易造成开裂破坏的问题,结合工程实践提出一种新的桥头路基处治方法——深层混凝土搭板处治法,将混凝土搭板放置一定深度,用以改善桥头路基的应力分布及变形.通过对Winkler弹性地基梁一端固定另一端自由时梁底地基反力的理论分析及现场试验研究得到,深层搭板底部的地基反力是从固定端到自由端一平滑过渡的曲线,且处治后路桥过渡段道路线形平顺,桥头沉降差较小,路基整体稳定.与EPS轻质换填处治方法进行比较,结果表明所提出的深层混凝土搭板处治法在控制桥头沉降差方面有较大优势.

Aimed at the concrete slab cracking with the impact action of vehicles,or the settlement under the slab for bridge approaches normally constructed with reinforced concrete slabs,this paper puts forward a new solution for settlement control at bridge approach embankment by adopting the deep-seated concrete slabs,which can redistribute the load in embankment.The result of theoretical analysis of the reaction under the concrete slabs in Winkler foundation model and that of field observation show that the reaction under the concrete slabs presents smooth evolution from the fixed end to the free end,the road alignment of transitional section between bridge and approach is smooth,the settlement is mitigated,and the road subgrade is stable.Compared with the EPS geofoam lightweight fill for the bridge approach embankment in the settlement control,the use of deep-seated concrete slabs has more advantages.