尼铁现代化项目中矩形空心桥台的优化设计

Optimal Design of Rectangular Hollow Abutment in Nigerian Railway Modernization Project

当前常用的时速200 km的铁路矩形空心桥台参考图中的桥台截面尺寸偏厚,安全富余量很大。为节约混凝土圬工量,希望在保证安全的前提下减少桥台截面尺寸。首先提出专门针对铁路矩形空心桥台台身截面计算的荷载图示,然后利用这一新的图示对拉伊铁路项目中使用的常规矩形空心桥台进行有限元分析,经过不断试算提出最优的截面尺寸。在钢筋用量基本不变的情况下,新尺寸桥台较原参考图中桥台的混凝土用量减少10%以上。对于项目所在地尼日利亚国水泥价格高昂的情况而言,桥台尺寸的这一优化将产生较大的经济效益。

The sectional dimension of railway rectangular hollow abutment commonly used in current reference diagram（ for 200 km/h） is comparatively thicker,resulting in excessive safety margin. In order to save concrete masonry,it is hoped that the abutment section could be reduced meanwhile safety is ensured. First,this paper presents a live load diagram for the calculation of the cross section of the railway rectangular hollow abutment. And then this new method is employed to conduct the finite element analysis of the conventional rectangular hollow abutment used in the Lagos-Ibadan railway project. The optimal section size is finally determined after continuous trail and the amount of concrete used in the optimized abutment is 10% less than that of the former one while the steel consumption remains much the same. This optimization brings about significant benefit for this local project where the cement is expensive.