文档介绍：摘要
迄今为止,横张预应力混凝土技术在T型梁、箱型梁、空心板桥三种常规简支梁桥中得以成功应用。为了将该技术由简支梁桥推广应用到更大跨度的连续梁桥中,课题组进行了富有创新性的探索和实践。本文以渝黔高速公路童家院子人行天桥为研究对象,讨论了设计理论和工程实践方面的有关问题。
本文所做的主要工作有:
1、从预应力的施工工艺方面着手,讨论了常规预应力混凝土连续梁桥的优缺点,在横张预应力混凝土技术固有优势的基础上,提出了横张预应力混凝土连续梁的设计构思,并对局部构造措施进行了细致描述。
2、对横张预应力混凝土连续梁的力学性能进行了分析计算,探讨了预应力损失、次内力、收缩、徐变等方面的问题。
3、提出用广义等效荷载法分析结构内力,与常规连续梁进行了对比分析;然后运用《公桥规》(征求意见稿)中截面验算公式作了强度、应力及变形等方面的验算。
4、利用有限元软件ANSYS对粘结锚固区、定位插销孔附近等局部区域的应力进行了仿真分析,并用图像方式显示了加强件对局部应力的改善情况。
5、讨论了横张预应力混凝土连续梁的可能张拉形式和相应张拉设备,所选择的方案得到了实践的验证。
【关键词】横张预应力、连续梁、设计构思、力学行为、等效荷载、次内力、ANSYS、应力分析
Exploration and Application of the Vertically Tensioned
Prestressed Concrete Continuous Beam Bridges
ABSTRACT
By now, the technology of vertically tensioned prestressed concrete(VTPC) has been essfully applied to T-beams, box beams and hollow slabs. In order to popularize this technique from simple supported beam bridges to larger-span continuous beam bridges, the project team has made creative exploration and practice. In this paper, we took Tongjiayuanzi overpass bridge on Yuqian expressway as the research object, and discussed some related problems about design theory and engineering practice.
The main work finished is listed below:
the point of prestressing construction technology, discussing the advantages and disadvantages of conventionally prestressed concrete continuous beam bridges, putting forward the design idea of the VTPC continuous beam bridge on the basis of its intrinsic merits, then explicating the local reinforcement.
and calculating the mechanical performance of the VTPC continuous beam, discussing such problems as prestress loss, secondary forces, shrinkage and creep.
the equivalent loads method to analyzing the structural interior forces, making a contrastive analysis with conventional continuous beam, then making a putation about strength, stress and deformation according to up-to-date “Design Code fore Highway Bridge and Culverts”.
the stresses of anchoring bond