无桥台倾斜弹性地基梁与双拱腿复合基础拱桥的分析与设计

Analysis and Design of Arch Bridges Erected on Jointed Foundations of Sloping Elastic Foundation Beams and Double Arch Legs

提出一种新的拱桥结构形式———无桥台倾斜弹性地基梁与双拱腿复合基础拱桥,作为需要良好地基设置巨型桥台以抵抗主拱圈水平推力及路堤土压力的传统的拱桥的替代工程解决方案建议,介绍了新拱桥的结构构造特点。基于子结构和有限元分析方法,采用文克勒线性地基模型,讨论了新拱桥的弹性地基梁基础与上部结构共同作用的力学计算模型,通过实例分析了地基弹性变形对主拱圈内力的影响,与有桥台拱桥相比较,这类桥梁具有结构合理、外形简洁、适应地基范围广的优点。

A new type of arch bridges- - arch bridges erected on the jointed foundations of sloping elastic foundation beams and double arch legs instead of abutments is proposed.They are the alternative structures of conventional arch bridges using massive abutments erected on high bearing capacity ground to resist horizontal arch ring action and lateral earth pressure loading due to lateral displacement of embankment.The structural features of the proposed arch bridges are introduced.Based on FEM, sub-stmcttairg, and linear WINKLER subgrade hypothesis, the mechanical model of subsoil-superstructure interaction of the proposed arch bridges is dismissed, the variation of the internal force of arch ring due to elastic subgrade defoimation is also explored with an numerical example. It is also demonstrated that the proposed arch bridges having the features of proper structure, brevity shape and fitting for wide-ranging subgrade environments in comparison to arch bridges with massive abutments.