40米简支梁桥设计计算书

本科毕业论文题目：龙头寨北江大桥施工图设计学院:城市建设学院专业:土木工程学号:200708141144学生姓名:指导教师:日期:二○一一年六月1摘要本设计是根据设计任务书的要求和《公路桥规》的规定,对龙头寨北江大桥进行设计。对该桥的设计，本着使桥梁与环境协调一致和经济的原则，本论文提出三种不同的桥型方案进行比选：方案一为预应力混凝土简支小箱梁梁桥，方案二为钢管混凝土下承式拱桥。方案三为双塔斜拉桥。通过比较它们在经济、美观、作用下的特性和实用性几方面，最终比较确定预应力混凝土简支小箱梁梁桥为推荐方案。本设计采用预应力混凝土简支梁桥，跨径布置为5×40m，主梁采用小箱梁，梁高为2m，桥墩（台）采用双柱墩（台）。首先进行桥型方案比选，对主桥进行总体结构设计，然后对上部结构进行内力、配筋计算，再进行强度、应力及变形验算，最后再确定下部结构采用以钻孔灌注桩为基础的双墩柱，采用盆式橡胶支座，并分别对桥墩和桩基础进行了计算和验算。经过对桥梁上下部结构计算，确定了施工图的最终方案，并依据计算书采用计算机绘制龙头寨北江大桥施工图。最后经过复核计算书以后，确定所有设计工作均符合设计任务书的要求。关键词：预应力混凝土简支梁桥；小箱梁;双柱桥墩（台）；钻孔灌注桩；2AbstractThisisaconstructiondocumentsdesignofamajorbridgethatisoverthemiddleofBeijianginLongtouzhai,accordingtodesigningassignmentandthestandardofroadandbridge.Forthepurposeofmakethebridgecorrespondingwiththeambienceandcostsaving,thispaperprovidesthreedifferenttypesofbridgeforselection:thefirstoneispre-stressedconcretebeamsmallboxgirderbridge;thesecondoneisCFSTthroughbridge.,andthethirdoneisdoublepyloncablestayedbridge.Afterthecomparisonsofeconomy,appearance,characteristicunderthestrengthandeffect,thefirstoneisselected.Thebridgebelongstotheprestressedconcretedstructuerwhichisasimplesupportedbeambridge.Thespanarrangmentsis5×40m.Thesuperstructureissmallboxgirder,theheightofthegrideris2m,andthepier(abutment)istwo-columnpier(abutment).Thisessayfocusesonthedesignandcalculationprocessofthebridge.Firstly,compareandchooseabestschemefrom3kindsofbridgetypes,andmakeanoverrallstructuredesignofthemainspan.secondly,performandcalculationoftheinternalforceandreinforcingbaronthesuperstructure.thirdlychecktheintensity,stressandthedeflection.finally,determinethetwo-columnpierofthebridgeisbasingonboredpile,andadoptpotrubberbearing.WhatismorethepiersandthePilefoundationsarecalculatedandcheckedrespectively.Aferthecalculationofthesuperstructureandsusstructureofbridge,theconstructiondocumentsisfinalised,andconstructiondrawingisprotractedbytheAutoCAD,accordingthecalculations.Finally,allofthedesignworkmeetstherequirementsofdesigningassignmentafterreviewingthecalculations.Keywords:Pre-stressedconcretebeambridge;Smallboxgirder;Two-columnpier(abutment);Boredpile;3目录绪论.............................................................................................................................................11设计说明...............................................................................................................................21.1设计依据、规范和技术指标....................................................................................21.1.1设计依据.........................................................................................................21.1.2主要技术标准.................................................................................................21.2主要材料及材料性能指标........................................................................................21.2.1主要材料.........................................................................................................21.2.2材料性能指标.................................................................................................32方案比选...............................................................................................................................32.1桥梁设计原则............................................................................................................32.2桥梁总跨径设计原则................................................................................................42.3桥梁分孔原则............................................................................................................42.4方案选定及比较........................................................................................................43上部结构计算.......................................................................................................................73.1设计基本资料............................................................................................................73.2箱型梁构造形式及设计参数....................................................................................83.3主梁作用效应计算..................................................................................................103.3.1永久作用效应计算（按边主梁计算）.......................................................103.3.2可变作用效应计算.......................................................................................123.3.3主梁作用效应组合.......................................................................................203.4预应力钢束的估算及其布置..................................................................................203.4.1预应力钢束数量的估算...............................................................................203.4.2预应力钢束布置...........................................................................................213.5计算主梁截面几何特性...........................................................................................253.5.1截面面积及惯性矩计算.................................................................................253.5.2截面净距计算...............................................................................................273.5.3截面几何特性总表........................