摘 要桥梁在设计过程中，上部结构（桥跨结构和支座系统）设计的合理性，影响整座桥梁的安全性、耐久性。通过一系列数据分析，对桥梁上部结构的一系列方案进行对比，选出最佳的上部结构设计方案，以达到满足交通需求、安全性且尽可能降低成本的目的。T 型截面桥梁两肋处的混凝土很大程度上被挖空，桥体自重大幅减轻。混凝土本身抗压能力远远大于其抗拉能力，因此下部受拉钢筋提供了抗拉部分的绝大部分拉力，下部钢筋的受拉作用得到了充分地发挥。所以预应力 T 型梁混凝土用量少，桥体自重小，上部的压力又混凝土来承担，下部的拉力由预应力钢筋来承担，结构和受理性因此能都能达到理想的状态。由于其混凝土简支 T 梁桥有构造简单、施工方便、受力明确，能充分发挥材料特性等特点，已经成为了中小跨桥梁形式的首选方案。预应力混凝土 T 形梁是一种简支 T 形梁桥结构，具有构造简单，造价低廉，具有较好的跨越能力现在被越来越多的中型、大型桥梁桥梁作为首选方案，而且因为其便于维护，也成为了国防建设的首选桥梁。关键词：简支梁桥；预应力；方案比选；有限元模型。ABSTRACTThe rationality of superstructure （bridge span structure and support system） design affects the safety and durability of the whole bridge in the process of bridge design. A series of schemes of bridge superstructure are compared, whilst the best superstructure design scheme is selected to meet the traffic demand, safety and economy through a series of data analysis.The concrete at the two ribs of T-section bridge is largely hollowed out, so the self weight of the bridge body is greatly reduced. The compressive capacity of concrete itself is far greater than its tensile capacity, so the tensile force of the tensile part is provided by the lower tensile reinforcement. Therefore, the amount of concrete used in prestressed T-beam is small, the weight of bridge body is small too. The upper pressure is borne by concrete, and the lower tension is borne by prestressed steel, so the structure and acceptability can reach the ...
