Transportation Research Record: Journal of the Transportation Research Board ( IF 1.7 ) Pub Date : 2021-09-02 , DOI: 10.1177/03611981211028607 Wadi H. Imseeh 1 , Khalid A. Alshibli 1 , Murad Y. Abu-Farsakh 2 , Ted A. Kniazewycz 3
The approach slab is constructed at bridge ends to serve as a smooth transition from the highway pavement to the bridge deck. However, motorists usually complain about a sudden change in elevation (bump) at the highway/approach slab (H/S) joint that causes a potential hazard for public safety, damage to vehicles, and rider discomfort. This paper develops a finite element (FE) analysis for the differential settlement at the H/S joint when supported by a strip footing that sits on compacted layers of soil embankment with uniaxial geogrid reinforcement. A parametric study was conducted to select the optimum design that consists of five geogrid layers equally spaced within a depth of 2 below the strip footing, where is the width of the footing. The inclusion of geogrid reinforcement did not only enhance the ultimate bearing stress of the strip footing but also redistributed the vertical loads over a wider region of soil embankment and thus reduced settlement. A case study is also presented for modeling the performance of a preliminary design proposed by Tennessee Department of Transportation (TDOT) for the retrofit of bridge ends. The FE analysis showed a 30%–40% improvement in the ultimate bearing stress of the strip footing when the geogrid reinforcement proposed by TDOT is extended to a depth of 1.5 below the footing.
中文翻译:
用于田纳西州桥梁引桥板支撑的土工合成材料增强填充材料
引桥板建在桥端,作为从公路路面到桥面的平滑过渡。然而,驾驶者通常会抱怨高速公路/引道板 (H/S) 接头处的高度突然变化(颠簸),这会对公共安全造成潜在危害、车辆损坏和骑手不适。本文针对 H/S 接头处的差异沉降进行了有限元 (FE) 分析,该基础由位于具有单轴土工格栅加固的土路堤压实层的条形基础支撑。进行了参数研究以选择由 5 个土工格栅层组成的最佳设计,这些土工格栅层在 2 在条形基础下方,其中 是基脚的宽度。土工格栅加固的加入不仅提高了条形基础的极限承载应力,而且还重新分配了更大范围的土路堤区域的垂直荷载,从而减少了沉降。还提供了一个案例研究,用于模拟田纳西州交通部 (TDOT) 提出的桥端改造初步设计的性能。有限元分析表明,当 TDOT 提出的土工格栅加筋延伸到 1.5 深度时,条形基础的极限承载应力提高了 30%–40% 在基础之下。