全长145.2m深茂铁路40+64+40m连续梁桥上部结构设计(含CAD图)(任务书,开题报告,论文说明书19000字,CAD图25张)
摘 要
这是一座铁路预应力混凝土连续梁桥,为双线铁路桥梁,主要设计桥梁的上部结构,设计荷载采用中-活载。
采用预应力混凝土连续梁桥,其桥跨布置为40+64+40m,全长为145.2m(含两侧梁端至边支座中心各0.6m)。主梁采用变高度变截面的单箱单室箱型截面,主梁的高度变化曲线采用半径为195.002m的圆曲线。桥面宽度为12.2m,中支座梁高5.2m,端部及中跨跨中梁高2.8m。主梁采用挂篮悬臂浇筑施工法,边跨现浇段采用满堂支架施工。
使用midas 软件进行建模分析,考虑施工过程体系转换和混凝土收缩徐变因素进行恒载内力计算。计算各控制截面内力影响线,并按最不利情况进行加载,求得活载内力包络图。根据各控制截面内力进行了估束和配筋计算,并绘制了梁体钢束布置图定义支座沉降组,按最不利组合求得支座沉降引起的最不利内力。依据规范选取截面系统温差模式,并计算温差引起的结构内力。分别按主力组合和主力附加力进行荷载组合,并得到结构组合内力包络图。最后,对各控制截面进行了强度、抗裂性、应力和变形验算,各项检算均满足铁路桥规对全预应力钢筋混凝土结构的要求。
关键词:连续梁;悬臂施工;内力计算;验算;midas
Abstract
This design is a prestressed concrete continuous beam bridge . It is a double line railway . The main job is to design the superstructure of the bridge. The load for design is the “ZK”live load.
A prestressed concrete continuous beam bridge with three spans of 40+64+40m was adopted. Its total span is 145.2m . First , the size of girder is determined;highly variable for the variable beam cross-section single-Box Single girder . And the box girder’s variation curve is a circular curve,which radiu is 195.002m.The bridge deck is 12.2m in width , the depth of beam at middle bridge seat is 5.2m ,and the depth of beam at mid-span is 2.8m .Balanced cantilever construction method is used in constructing main girder, and the cast-in-situ segment is constructed by full scaffold construction method.
Then the Midas program is used to calculate the internal force caused by dead load of the first stage considering the construction stage ,after imposing the second stage dead load on the complete system . The internal force of the stage is calculated . The internal force influence lines of the control section is calculated ,then the live load is imposed according to the most adverse circumstances to get the Force Envelope .According to the internal force of control sections the number of per-stressing steel stands is estimated and the per-stressing steel stands are arranged in the bridge .The program is used to determine the most adverse circumstances and calculate the internal force after defining the settlement groups of the basis.The temperature load is imposed consider the shrinkage and creep of the concrete . Then combination of load effects is made acoording to the Main force combination and the Main force plus additional force combination . Finally a check is made of the bearing capacity the ability to resist crack and the sterss of the control section ,all the requirements can be met .
Keywords: Continuous beam; balanced cantilever construction; Internal force calculation; Checking computation; Midas