- 3.67 MB
- 109页
- 1、本文档共5页,可阅读全部内容。
- 2、本文档内容版权归属内容提供方,所产生的收益全部归内容提供方所有。如果您对本文有版权争议,可选择认领,认领后既往收益都归您。
- 3、本文档由用户上传,本站不保证质量和数量令人满意,可能有诸多瑕疵,付费之前,请仔细先通过免费阅读内容等途径辨别内容交易风险。如存在严重挂羊头卖狗肉之情形,可联系本站下载客服投诉处理。
- 文档侵权举报电话:19940600175。
'摘要本毕业设计题目为乌兰察布市政府办公楼设计。其工程用地基本为长方形,东西宽约20m,南北长约80m,建筑面积约9000m2;地上9层,建筑高度38.4m。本设计主要进行了结构方案中横向框架框架的抗震设计。在确定框架布局之后,先进行了层间荷载代表值的计算,接着利用顶点位移法求出自震周期,进而按底部剪力法计算水平地震荷载作用下大小,进而求出在水平荷载作用下的结构内力(弯矩、剪力、轴力)。接着计算竖向荷载(恒载、活荷载以及雪荷载)作用下的结构内力。是找出最不利的一组或几组内力组合。选取最安全的结果计算配筋并绘图。此外还进行了结构方案中的室内楼梯的设计(完成了平台板,梯段板,平台梁等构件的内力和配筋计算及施工图绘制)、楼盖的设计(完成了板的配筋和次梁的配筋)、基础的设计(完成了独立基础和联合基础的配筋)。关键词:配筋荷载传递途径剪力跨度框架V
AbstractThegraduationprojectentitledDesignWulanchabuCityGovernmentbuilding.Itsbasicrectangularprojectsitefromeasttowestwidthof20m,theSouthandtheNorthabout80m,theconstructionareaofabout9000m2;layer9ontheground,buildingheight38.4m.Thepurposeofthedesignistodotheanti-seismicdesigninthelongitudinalframesofaxis.Whenthedirectionsoftheframesisdetermined,firstlytheweightofeachfloormiscalculated.Thenthevibratecycleiscalculatedbyutilizingthepeak-displacementmethod,thenmakingtheamountofthehorizontalseismicforcecanbegotbywayofthebottom-shearforcemethod.Theseismicforcecanbeassignedaccordingtotheshearingstiffnessoftheframesofthedifferentaxis.Thentheinternalforce(bendingmoment,shearingforce,axialforcesnowforce)inthestructureunderthehorizontalloadscanbeeasilycalculated.Afterthedeterminationoftheinternalforceunderthedeadandliveloads,thecombinationofinternalforcecanbemadebyusingtheExcelsoftware,whosepurposeistofindoneorseveralsetsofthemostadverseinternalforceofthewalllimbsandthecoterminousgirders,whichwillbethebasisofprotractingthereinforcingdrawingsofthecomponents.Thedesignofthestairsisalsobeapproachedbycalculatingtheinternalforceandreinforcingsuchcomponentsaslandingslab,stepboardandlandinggirderwhoseshopdrawingsarecompleted.Thedesignoffloorslab,foundation.keywords:reinforcementloadpathshearspanframeV
目录摘要IABSTRACTII第1章绪论11.1设计题目11.2设计资料11.2.1水文地质资料11.2.2气象资料11.3设计要求21.3.1建筑部分21.3.2结构部分21.4设计成果21.4.1概况21.4.2设计施工图2第2章设计概况32.1工程概况32.2具体要求32.3设计依据32.4设计过程3第3章结构布置及计算简图5第4章重力荷载计算84.1屋面及楼面的永久荷载标准值84.2屋面及楼面可变荷载标准值84.3梁、柱、墙、窗、门重力荷载计算94.4重力荷载代表值11V
第5章框架侧移刚度计算14第6章横向水平荷载作用下框架结构的内力和侧移计算196.1横向水平荷载作用下框架结构的内力和侧移计算196.1.1横向自振周期计算196.1.2水平地震作用及楼层地震剪力计算206.1.3水平地震作用下的位移验算216.1.4水平地震作用下框架内力计算226.2横向风载作用下框架结构的内力和侧移计算286.2.1风荷载标准值286.2.2风荷载作用下水平位移验算306.2.3风荷载作用下框架结构内力计算31第7章竖向荷载作用下框架结构的内力计算357.1横向框架内力计算357.1.1计算单元357.1.2荷载计算367.2横向框架内力组合477.2.1结构抗震等级477.2.2框架梁内力组合477.2.3框架柱内力组合49第8章截面设计568.1框架梁568.2框架柱608.2.1剪跨比和轴压比验算608.2.2柱正截面承载力计算618.2.3柱斜截面受剪承载力计算648.3节点设计668.3.1节点核心区剪力设计值668.3.2节点核心区截面验算678.3.3节点核心区截面抗剪强度验算688.4构造要求68V
8.4.1梁的构造688.4.2柱的构造718.5楼梯计算748.5.1计算简图的确定758.5.2梯段板计算758.5.3平台板设计778.5.4平台梁设计788.6板的设计798.6.1楼面板②区格板798.6.2楼面板D区格板82结论85致谢86参考文献87附录188附录295V
第1章绪论1.1设计题目乌兰察布市政府办公楼设计1.2设计资料1.2.1水文地质资料抗震设防烈度7度,建筑场地类别二类,场地特征周期为0.35秒,基本雪压S0=0.40kN/㎡,基本风压ω0=0.60kN/㎡.地区表面为一般粘性土层,下部为砂类土,水质无侵蚀性,承载力情况良好(承载力值待定)。1.2.2气象资料冬季室外平均温度-22℃绝对最高温度30℃绝对最低温度-25℃全年雨季7-8月最大降雨量31.7㎜/10min104
1.3设计要求1.3.1建筑部分:总平面,平立剖面,主要节点构造1.3.2结构部分:(1)结构方案与布置;(2)框架剪力墙结构协同工作分析;(3)结构侧移计算;(4)框架剪力墙受力分析和截面计算。1.4设计成果1.4.1概况:建筑设计说明,结构设计说明,结构计算书1.4.2设计施工图:(1)建筑施工图:底层平面图,标准层平面图,主要平面图,主要剖面图,节点详图(2)结构施工图:结构布置图,框架和楼面配筋图104
第2章设计概况2.1工程概况拟建一综合办公楼,建筑面积9000平方米,受场地限制,宽度20米,长度80米,设计要求框架结构,丙类建筑。2.2具体要求政府办公楼:8-10人标准间(60㎡左右);6-8人带套间办公室(80㎡左右);每层有单人办公室2-4间,小型会议室1间;大型多功能会议室(200㎡左右)2间。2.3设计依据本设计依据各种现行建筑设计规范、结构设计规范,设计说明书,规划位置图要求进行设计。2.4设计过程(1)确定结构体系与结构布置;(2)根据经验对构件进行初估;(3)确定计算模型及计算简图;(4)荷载计算;104
(5)内力计算及组合;(6)构件及节点设计;(7)编写设计任务说明书;(8)图纸绘制。104
第3章结构布置及计算简图根据该房屋的使用功能及建筑设计的要求[1],进行了建筑平面、立面及剖面设计,其标准层建筑平面、结构平面和剖面示意图分别见大图,主体结构共9层,底层层高4.2m,其余各层层高均为3.9m,共35.4m。突出塔楼部分为电梯间,层高3米。填充墙采用240mm厚的粘土空心砖。门为木门,门洞尺寸有0.9m×2.4m,3.0m×2.4m,1.5m×2.4m,1.2×2.4m。入口处为玻璃转门,门洞尺寸为2.4×2.7m,弹簧门,门洞尺寸为1.8×2.7m。窗为铝合金窗,洞口尺寸有2.4m×2.1m,2.1m×2.1m,1.8m×2.1m,3.0m×2.1m。楼盖及屋盖均采用现浇钢筋混凝土结构[2],楼板厚度取100mm。梁截面高度按梁跨度的1/12~1/8估算,由此估算的梁截面尺寸见表3-1,表中还给出了各层梁、柱和板的混凝土强度等级。其设计强度C35(fc=16.7N/m²,ft=1.57N/m²),C30(fc=14.3N/m²,ft=1.43N/m²)。表3-1梁截面尺寸及各层混凝土强度等级层次混凝土强度等级横梁(b×h),mmBC跨,DE跨AB跨CD跨纵梁(b×h),mm次梁(b×h),mm2~9C30300×600300×400300×600300×5001C35350×600350×400350×600300×500柱截面尺寸可根据公式(3-1)、(3-2)N=βFgEn(3-1)AC≥N/[μN]fc(3-2)估算。由于本框架结构的抗震等级为二级,其轴压比限值[μN104
]=0.8,各层的重力代表值近似取12kN/m²。由结构平面布置图可知边柱及中柱的负荷面积分别为7.2×3.6m²和7.2×4.8m²。由公式(3-2)得第一层柱截面面积为边柱AC≥1.3×7.2×3.6×12×10³×8/0.8×16.7=236196mm²中柱AC≥1.25×7.2×4.8×12×10³×8/0.8×16.7=275625mm²如取柱截面为正方形,则边柱和中柱截面高度分别为486mm和525mm。根据上述计算结果并综合考虑其它因素,本设计中柱截面尺寸取值如下:1层700mm×700mm2~5层600mm×600mm6~9层550mm×550mm基础采用肋梁式筏板基础,基础埋深2.5米,肋梁高度取1.2米。框架结构计算简图如下图所示。取顶层柱的形心线作为框架柱的轴线;梁轴线取至板底,2-9层柱高即为层高,取3.9m,底层柱高度从基础顶面取至一层板底,即h1=4.2+0.6+2.5-1.2-0.1=6m。104
(a)横向框架(b)纵向框架图3-1框架结构计算简图104
第4章重力荷载计算4.1屋面及楼面的永久荷载标准值[8]屋面(上人):30厚细石混凝土保护层22×0.03=0.66kN/m²三毡四油防水层0.40kN/m²20厚水泥砂浆找平层20×0.02=0.40kN/m²150厚水泥蛭石保温层5×0.15=0.75kN/m²100厚钢筋混凝土板25×0.1=2.50kN/m²V型轻钢龙骨吊顶0.25kN/m²合计4.96kN/m²1~8层楼面:瓷砖地面(包括水泥粗砂打底)0.55kN/m²100厚钢筋混凝土板25×0.1=2.50kN/m²V型轻钢龙骨吊顶0.25kN/m²合计3.30kN/m²4.2屋面及楼面可变荷载标准值上人屋面均布活荷载标准值2.0kN/m²104
楼面活荷载标准值2.0kN/m²屋面雪荷载标准值sk=μr·s0=1.0×0.4=0.4kN/m²式中:μr为屋面积雪分布系数,取μr=1.0。4.3梁、柱、墙、窗、门重力荷载计算梁、柱可根据截面尺寸,材料容重及粉刷等[8]计算出单位长度上的重力荷载[3];对墙、门、窗等可计算出单位面积上的重力荷载。计算结果见表4-1104
表4-1梁、柱重力荷载标准值层次构件bmhmγKN/m³βgKN/m³limnGiKN∑GiKN1边横梁0.350.60(0.40)251.055.513(3.675)6.410(4.120)86317.550(105.840)2251.68中横梁0.350.60(0.40)251.055.513(3.675)6.390(1.700)88317.550(70.560)次梁0.300.50251.053.946.4606170.100纵梁0.350.60251.055.526.500321270.08柱0.700.70251.1013.486.000383072.302~5边横梁0.300.60(0.40)251.054.725(3.150)6.600(4.200)86272.160(90.720)1954.26中横梁0.300.60(0.40)251.054.725(3.150)6.600(1.800)88272.160(60.480)次梁0.300.50251.053.946.4606170.100纵梁0.300.60251.054.7256.600321088.64柱0.600.60251.109.93.90381467.166~9边横梁0.300.60(0.40)251.054.725(3.150)6.650(4.250)86272.160(90.720)1954.26中横梁0.300.60(0.40)251.054.725(3.150)6.650(1.850)88272.160(60.480)次梁0.300.50251.053.946.4606170.100纵梁0.300.60251.054.7256.650321088.64柱0.550.55251.108.3193.900381232.84注:1)表中β为考虑梁、柱的粉刷层重力荷载而对其重力荷载的增大系数;g表示单位长度构件重力荷载;n为构件数量。2)梁长度取净长;柱长度取层高104
墙体为370mm厚钢筋混凝土,外墙面贴瓷砖(0.5kN/m²),内墙面为20mm厚抹灰,则外墙单位墙面重力荷载为0.5+15×0.37+17×0.02=4.44kN/m²内墙为240mm厚粘土空心砖,两侧均为20mm厚抹灰,则内墙单位墙面重力荷载为15×0.24+17×0.02×2=4.28kN/m²木门单位面积重力荷载为0.2kN/m²;铝合金窗单位面积重力荷载取0.4kN/m²。4.4重力荷载代表值集中于各质点的重力荷载Gi,为计算单元范围内各层楼面上的重力荷载代表值及上下各半层的墙、柱等重量。各可变荷载的组合值系数按表4-2的规定采用[3]:无论是否为上人屋面,其屋面上的可变荷载均取雪荷载。表4-2可变荷载组合值系数可变荷载种类组合值系数雪荷载0.5屋面积灰荷载0.5屋面活荷载不考虑按实际情况考虑的楼面活荷载1.0按等效均布荷载考虑的楼面活荷载藏书库、档案库0.8其他民用建筑0.5吊车悬吊物重力硬钩吊车0.3104
简单的计算过程如下:顶层:屋面恒载、50﹪屋面荷载、纵横梁的自重、半层柱的自重、半层墙的自重。其它层:楼面荷载、50﹪楼面均布荷载、纵横梁自重、楼面上、下各半层的柱及纵横墙自重。主体结构总面积A=16.8×50.4+4.8×7.2×4=846.72+69.12=984.96m第一层(楼板重+梁柱重+墙体重+门窗重)G1=3.3×984.96+0.5×2.0×984.96+2251.68+3072.30+4.2×(7.2-0.7)×4.28×24+4.2×(7.2-0.7)×4.44×17+4.2×(2.4-0.7)×4.44×2+4.2×(4.8-0.7)×4.44×4=14793.399kN第二层G2=3.3×984.96+0.5×2.0×984.96+1954.26+1467.16+3.9×(7.2-0.6)×4.28×29+3.9×(4.8-0.6)×4.28×2+3.9×(7.2-0.6)×4.44×18+3.9×(2.4-0.6)×4.44×2+3.9×(4.8-0.6)×4.44×4=13402.197kN第三~五层算法和第二层类似第六层G5=3.3×984.96+0.5×2.0×984.96+1954.26+1232.84+3.9×(7.2-0.55)×4.28×29+3.9×(4.8-0.55)×4.28×2+3.9×(7.2-0.55)×4.44×18+3.9×(2.4-0.55)×4.44×2+3.9×(4.8-0.55)×4.44×4=13214.529kN第七、八层算法与第六层类似第九层(梁柱重/2+墙体/2+门窗重+楼面恒载+楼面活荷载+楼面雪荷载)G9=4.96×984.96+0.5×2.0×984.96+(1954.26+1232.84/2+[3.9×(7.2-0.104
55)×4.28×29+3.9×(4.8-0.55)×4.28×2+3.9×(7.2-0.55)×4.44×18+3.9×(2.4-0.55)×4.44×2+3.9×(4.8-0.55)×4.44×4]/2=10359.962kN各层重力荷载代表值如下:第一层G1=14793.399kN第二层G2=13402.197kN第三~五层G3=G4=G5=G2=13402.197kN第六层G5=13214.529kN第七~八层G7=G8=G5=13214.529kN第九层G9=10359.962kN计算结果见图4-1。图4-1各质点的重力荷载代表值104
第5章框架侧移刚度计算表5-1横梁线刚度ib计算表类别层次ECN/mm²b×hmm×mmI0mm4mmECI0/N·mm1.5ECI0/N·mm2ECI0/N·mm边横梁13.15×104350×600350×4006.3×1091.9×109720048004.140×1001.875×1005.520×10102.500×10102~93.0×104300×600300×4005.4×1091.6×1094.500×10102.000×1010走道梁13.15×104350×4001.9×10924003.75×10105.00×10102~93.0×104300×4001.6×1093.00×10104.00×1010表5-2柱线刚度ic计算表层次hc,mmEC,N/mm²b×h,mm×mmIc,mm4EcIc/hc,N·mm160003.15×104700×7002.001×101010.500×10102~539003.00×104600×6001.080×10108.308×10106~939003.00×104550×5507.626×1095.866×1010根据梁、柱线刚度比K的不同,结构平面布置中的柱可分为中框架中柱和边柱、边框架中柱和边柱以及楼、电梯间柱等。现以第2层C-3柱的侧移刚度计算为例,说明计算过程,其余柱的计算过程从略,计算结果见表5-3。第2层C-3柱及与其相连的梁的相对线刚度=1.145αc=1.145/(2+1.145)=0.364104
由公式5-1(5-1)得D=0.364×=23859N/mm框架柱侧移刚度D值计算结果见表5-3。图5-3C-3柱与其相连的梁的相对线刚度104
表5-3框架柱侧移刚度D值(N/mm)层号位置柱根数6~9边框架边柱0.5750.2561032040.4850.181110772边框架中柱1.2600.4001748820.9850.3302166121.3350.385201222中框架边柱0.7800.2811226020.9750.3281432120.5200.2061352540.6500.245160772中框架中柱1.7600.4682045520.7800.2811226021.9550.4942160021.1730.3792423641.3030.3852546263~5边框架边柱0.4950.1891340240.4520.217187992104
边框架中柱1.1250.3612692120.8350.2793421520.7890.295318762中框架边柱0.6000.2451879620.8250.2892103420.4400.1901923740.5600.321233342中框架中柱1.4500.4373078920.6000.2461786920.8230.2962354920.9950.3353546741.1450.3642515162边框架边柱0.2330.1121643840.2250.102203412边框架中柱0.5860.2263156720.4230.1563457120.4520.185368732中框架边柱0.3880.1452035220.4260.1782654220.3280.1202126940.2580.128259082104
中框架中柱0.7660.2263885620.3980.2872035420.8560.1394123720.5430.2894236540.2870.2312549761边框架边柱0.6040.4253597540.5340.407459782边框架中柱1.3780.5444717621.0660.3423486721.3240.569618892中框架边柱0.8090.467323947921.0120.6004236520.5460.4245034840.7090.456501202中框架中柱1.7800.6095156820.8020.4763987521.8970.6785318921.2380.4596545841.4890.573679826104
第6章横向水平荷载作用下框架结构的内力和侧移计算6.1横向水平荷载作用下框架结构的内力和侧移计算6.1.1横向自振周期计算结构顶点的假想位移由公式(6-1)~(6-3)(6-1)(6-2)(6-3)计算。计算过程见表6-1。表6-1结构顶点的假想位移计算层次Gi,kNVGi,kN∑Di,N/mm△μi,mmμi,mm910359.96210359.96211243559.21444.31813214.52923574.491112435520.9435.1713214.52936789.020112435532.7414.2613214.52950003.549112435544.4381.5513402.19763405.746125453656.5337.1413402.19776807.943125453668.0280.6313402.19790210.140125453675.5212.6213402.197103612.337135665480.6137.1114793.399118405.736209781056.556.5按公式(6-4)104
T1=1.7YT(μT)1/2(6-4)计算基本周期T1,其中μT的量钢为m,取YT=0.7,则T1=1.7×0.7×(0.4431)1/2=0.79s6.1.2水平地震作用及楼层地震剪力计算本例中,结构高度不超过40m,质量和刚度沿高度分布比较均匀,变形以剪切型为主,故可用底部剪力法[1]计算水平地震作用。结构总水平地震作用标准值计算如下:Geq=0.85∑Gi=0.85(14793.399+13402.197×4+13214.529×3+10359.962)=0.85×118405.736=100644.88kNa1=(Tg/T1)0.9amax=(0.30/0.79)0.9×0.08=0.033FEK=a1Geq=0.033×100644.88=3368.42kN因1.4Tg=1.4×0.30=0.42s1.5,由表6-6可知,沿房屋高度在1.084~1.341范围内变化,即风压脉动的影响较大。因此,该房屋应考虑风压脉动的影响。框架结构分析时,应按静力等效原理将分布风荷载转化为节点集中荷载。例如第六层的集中荷载F6的计算过程如下:F6=(5.871+3.669+5.455+3.409)×3.9×1/2+[(6.291-5.871)+(3.932-3.669)]×3.9×1/2×1/3+[(5.871-5.455)+(3.669-3.403)]×3.9×1/2×2/3=37.21kN各层节点集中荷载见表6-8,图如6-3所示。表6-8各层节点集中荷载层次123456789集中荷载32.3027.0330.9932.8735.4537.2140.2342.1544.30104
图6-3框架上的风荷载6.2.2风荷载作用下水平位移验算表6-9风荷载作用下框架层间剪力及侧移计算层次123456789Fi/KN32.3027.0330.9932.8735.4537.2140.2342.1544.30Vi/KN322.53290.23263.20232.21199.34163.89126.6886.4544.30∑Di/N/mm)97380122684113596113596113596123122123122123122123122△μi/mm3.3122.3662.3172.0441.7551.3311.0290.7020.360μi/mm3.3125.6787.99510.03911.79413.12514.15414.85615.216△μi/hi1/18121/16481/16831/19081/22221/29301/37901/55561/10833104
风荷载作用下框架最大层间位移角为1/1812<1/550,满足要求。6.2.3风荷载作用下框架结构内力计算表6-10风荷载作用下边柱端弯矩及剪力计算层次/m,N/mmy93.91124355195118.140.7670.309.5222.2283.911243551951114.360.7670.38221.3934.6173.911243551951120.680.7670.43835.3345.3363.911243551951126.290.7670.4546.1456.3953.912545362163726.140.4990.4545.8856.0743.912545362163728.760.4990.4550.4761.6933.912545362163730.100.4990.4552.8364.5623.913566542358533.580.5560.5065.4865.4816.020978102059539.020.5730.732119.9643.92表6-11风荷载作用下中柱端弯矩及剪力计算层次/m,N/mmY93.91124355420508.201.2610.37411.8319.8183.911243554205012.451.2610.37418.1630.4073.911243554205022.991.2610.37433.5356.1263.911243554205030.601.2610.37444.6374.7153.912545363516142.720.9650.4778.3188.3043.912545363516156.400.9650.47103.38116.5833.912545363516164.940.9650.47119.04134.2323.913566543775772.481.0730.45127.20155.4716.020978102809591.100.8020.65233.40125.68104
表6-12风荷载作用下梁端弯矩﹑剪力及柱轴力层次边梁走道梁柱轴力MblMbrlVbMblMbrlVb边柱N中柱N922.229.077.24.3510.7410.742.48.95-4.35-4.60844.1319.347.28.8222.8922.892.419.08-13.17-14.86766.7234.027.213.9940.2640.262.433.55-27.16-34.42691.7249.577.219.6258.6758.672.448.89-46.78-63.695102.160.887.222.6572.0572.052.460.04-69.43-101.084107.5789.267.227.34105.63105.632.488.03-96.77-161.773115.03108.837.231.09128.78128.782.4107.22-127.86-237.902118.31125.737.233.89148.78148.782.4123.98-161.75-327.991109.40114.557.231.28138.33138.332.4114.22-193.03-410.93横向框架在水平风荷载作用下的弯矩图及梁端剪力和轴力图如图6-4,图6-5所示。104
图6-4风荷载作用下框架弯矩图104
图6-5风荷载作用下梁端剪力及柱轴力图104
第7章竖向荷载作用下框架结构的内力计算7.1横向框架内力计算7.1.1计算单元取④轴线横向框架进行计算,计算单元宽度为7.2m,由于房间内布置有次梁,故直接传给该框架的楼面荷载如下图中的阴影线所示,计算单元范围内其余楼面则通过次梁和纵向框架梁以集中力的形式传给横向框架[9],作用于各节点上。由于纵向框架梁的中心线与柱的中心线不重合,因此在框架节点上还有集中力矩。图7-1横向框架计算单元104
7.1.2荷载计算1恒载计算q1、q1´代表横梁自重,为均布荷载形式。对于第9层q1=4.95kN/m,q1´=3.09kN/mq2和q2´分别为房间和走道板传给横梁的梯形荷载和三角形荷载[3],由图7-2所示几何关系可以得出q2=4.96×3.6=17.856kN/mq2´=4.96×2.4=11.904kN/mP1、P2分别为由边纵梁、中纵梁直接传给柱的恒载,它包括梁自重、楼板重和女儿墙等重力荷载,计算如下:图7-2各层梁上作用的恒载P1=[(3.6×2.4×1/2)×2+(2.4+7.2)/2×2.4]×4.96+5.513×7.2+4.33×7.2/2+5.06×1.05×7.2=193.53kNP2=[(3.6×2.4×1/2)×2+(2.4+7.2)/2×2.4+(3.6+2.4)/2×1.2×2]×4.96+5.513×7.2+4.33×7.2/2=190.99kN集中力矩104
M1=P1e1=193.53×(0.55-0.3)/2=24.19kN·mM2=P2e2=190.99×(0.55-0.3)/2=23.87kN·m对6~8层,q1包括梁自重和其上横墙自重,为均匀荷载。其它荷载计算方法同第9层,结果为q1=4.95+3.05×2.7=13.185kN/mq1´=3.09kN/mq2=3.3×3.6=11.88kN/mq2´=3.3×2.4=7.92kN/mP1=(3.6×2.4×2)×3.3+5.513×7.2+4.33×3.3+5.06×(7.2×3.3-1.5×2.4×2)+0.4×1.5×2.4×2=197.68kNP2=(3.6×2.4×2+6×1.05)×3.3+5.513×7.2+4.33×3.3+4.56×3.3×(7.2-0.55)=229.61kN集中力矩M1=P1e1=197.68×(0.55-0.3)/2=24.71kN·mM2=P2e2=229.61×(0.55-0.3)/2=28.70kN·m对2~5层q1=13.185kN/mq1´=3.09kN/mq2=11.88kN/mq2´=7.92kN/mP1=(3.6×2.4×2)×3.3+5.513×7.2+4.33×3.3+5.06×(7.2×3.3-1.5×2.4×2)+0.4×1.5×2.4×2=196.85kNP2=(3.6×1.8×2+7.2×1.2)×3.3+5.513×7.2+4.33×3.3+4.56×3.3×(7.2-0.6)=219.07kN集中力矩M1=P1e1=196.85×(0.6-0.3)/2=29.53kN·mM2=P2e2=219.07×(0.6-0.3)/2=32.86kN·.m对第1层104
q1=4.95+3.05×3.3=15.0kN/mq1´=3.09kN/mq2=11.88kN/mq2´=7.92kN/mP1=(3.6×2.4×2)×3.3+5.513×7.2+4.33×3.3+5.06×(7.2×3.31.5×2.4×2)+0.4×1.5×2.4×2.0=215.90kNP2=(3.6×3.6+7.2×1.2)×3.3+5.513×7.2+4.33×3.3+4.56×3.3×(7.2-0.7)=218.32kN集中力矩M1=P1e1=215.90×(0.7-0.3)/2=43.18kN·mM2=P2e2=218.32×(0.7-0.3)/2=43.66kN·m2.活荷载计算活荷载作用下各层框架梁上的荷载分布如下图所示:图7-3各层梁上作用的活载对于第9层q2=3.6×2.0=7.2kN/mq2´=2.4×2.0=4.8kN/m104
P1=(3.6×2.4×2)×2.0=34.56kNP2=(3.6×2.4×2+7.2×1.2)×2.0=51.84kNM1=P1e1=34.56×(0.55-0.3)/2=4.32kN·mM2=P2e2=51.84×(0.55-0.3)/2=6.48kN·m同理,在屋面雪荷载作用下q2=0.72kN/mq2´=0.48kN/mP1=2.592kNM1=0.324kN·mP2=4.032kNM2=0.504kN·m对6~8层q2=3.6×2=7.2kN/mq2´=2.4×2=4.8kN/mP1=(3.6×2.4×2)×2=34.56kNP2=(3.6×2.4×2+6×1.2)×2=48.96kNM1=P1e1=34.56×(0.55-0.3)/2=4.32kN·mM2=P2e2=48.96×(0.55-0.3)/2=6.12kN·m对2~5层q2=7.2kN/mq2´=4.8kN/mP1=25.92kNP2=40.32kNM1=P1e1=25.92×(0.6-0.3)/2=4.32kN·mM2=P2e2=40.32×(0.6-0.3)/2=6.12kN·m对第1层q2=7.2kN/mq2´=4.8kN/mP1=25.92kNP2=40.32kNM1=P1e1=25.92×(0.7-0.3)/2=5.18kN·mM2=P2e2=40.32×(0.7-0.3)/2=8.06kN·m将上述计算结果汇总,见表7-1和表7-2104
表7-1横向框架恒载汇总表层次q1kN/mq1´kN/mq2kN/mq2´kN/mP1kNP2kNM1kN·mM2kN·m94.953.0917.85611.90193.53190.9924.1923.876~813.183.0911.887.92197.68229.6124.7128.702~513.183.0911.887.92196.85219.0729.5332.86115.003.0911.887.92215.90218.3243.1843.66表7-2横向框架活载汇总表层次q2,kN/mq2´,kN/mP1,kNP2,kNM1,kN·mM2,kN·m97.24.834.5651.844.326.486~87.24.834.5648.964.326.122~57.24.825.9240.324.326.1217.24.825.9240.325.188.06注:表中括号内数值对应于屋面雪荷载作用情况。3.内力计算梁端、柱端弯矩采用弯矩二次分配法计算。由于结构和荷载均对称,故计算时可用半框架。弯矩计算过程和弯矩图如下所示。梁端剪力可根据梁上竖向荷载引起来的剪力与梁端弯矩引起的剪力相叠加而得。柱轴力可由梁端剪力和节点集中力叠加而得到。计算柱底轴力还需要考虑柱的自重,如表7-3和表7-4所示。104
图7-4恒载作用下横向框架弯矩的二次分配104
图7-5活载作用下横向框架弯矩的二次分配104
图7-6恒载作用下竖向荷载作用的框架弯矩图104
图7-7活载作用下竖向荷载作用的框架弯矩图104
表7-3恒载作用下梁端剪力及柱轴力(KN)层次荷载引起剪力BC跨CD跨弯矩引起剪力BC跨CD跨总剪力BC跨CD跨柱轴力BC跨CD跨N顶N底N顶N底958.458.78-17.72.240.7558.4510.9823428253.14250.42257.58884.746.95-16.20.484.468.547.35516.36542.85555.92589.05784.746.95-15.00.684.469.747.55798.44832.56862.82920.53684.746.95-15.10.684.4069.747.551080.521122.271169.721252.00584.746.95-15.10.684.4069.747.551361.771431.501466.081596.18484.746.95-15.10.680.4069.747.55639.021740.731762.441940.44384.746.95-11.40.280.5073.347.151916.372049.962062.002284.64284.746.95-9.120.181.1075.627.052194.322382.112363.742447.58188.968.31-12.30.484.3276.668.712494.542526.872667.432763.28104
表7-4活载作用下梁端剪力及柱轴力(KN)层次荷载引起剪力BC跨CD跨弯矩引起剪力BC跨CD跨总剪力BC跨DC跨柱轴力B柱C柱N顶=N底N顶=N底912.962.52-2.230.8110.7311.293.3345.2963.13812.962.52-1.260.2311.7012.452.7591.55124.54712.962.52-1.240.3211.6212.752.84137.73158.68612.962.52-1.240.3211.6212.752.84183.91210.48512.962.52-1.240.3211.6212.752.84211.45253.64412.962.52-1.240.3211.6212.752.84248.99296.80312.962.52-0.540.2812.4212.982.80287.33339.92212.962.52-0.420.2212.5413.032.74325.79382.98112.962.52-0.500.2512.4612.992.77364.17426.07104
7.2横向框架内力组合7.2.1结构抗震等级结构的抗震等级可根据结构类型、地震烈度、房屋高度等因素,由查表可知,本工程的框架为二级抗震等级。7.2.2框架梁内力组合本例考虑了四种内力组合[2],即1.2(SGk+0.5SQk)+1.3SEk,1.35SGk+SQk,1.2SGk+1.26(SQk+SWk)和1.2SGk+1.4SQk。此外,对于本工程,1.2SGk+1.4SQk这种内力组合与考虑地震作用的组合相比一般比较小,对结构设计不起控制作用,故不予考虑。各层梁的内力组合结果见表7-5,表中SGk、SQk两列中的梁端弯矩M为经过调幅后的弯矩(调幅系数取0.8)。104
表7-5框架梁内力组合表层次截面位置内力→←→←一层BM-78.54-14.65109.40126.0-14.78-113.86-0.61-200.17-63.843-67.176160.35V84.3210.7331.2834.79163.54136.65143.5868.73163.445151.908CM-91.34-15.38115.82124.4-22.17-100.4975.37-148.57-61.073-63.988V76.6611.2931.2834.79163.54136.65143.5868.73163.445151.908CM-0.14-4.12137.06150.227.65-45.5098.84-110.12-9.15-9.222260.39V8.713.33114.22125.247.01-22.66107.39-91.6212.6412.528跨间M________75.9964.39150.6490.2175.3671.37M________73.4873.48121.3685.6210.659.49五层BM-71.47-14.96115.0382.4536.57-181.5139.14-125.82-72.244-75.584153.67V84.4011.6222.6523.37150.8285.20103.8360.37127.359119.832CM-74.34-15.6160.8885.8249.93-165.0745.67-114.33-57.3-60.072V69.7412.7522.6523.37150.8385.21103.8360.37127.359119.832CM-9.52-2.2172.05101.591.70-109.1569.10-80.17-8.9655-9.012210.97V7.552.8460.0484.63107.15-84.1278.47-63.6911.90511.868跨间M________77.6251.53144.23110.1260.1261.52M________50.6550.65155.96155.968.568.23九层BM-55.1420.5122.2216.8881.33-145.82-16.81-44.39-41.688-30.43255.69V84.3212.464.354.41120.9651.9862.7454.1391.867588.284CM-60.73-16.249.0714.8661.66-166.40-16.8-45.66-52.125-54.648V76.6612.994.354.4148.20-20.7813.354.7314.37314.064CM-15.32-4.1310.7417.9493.88-119.185.51-21.50-12.965-13.07260.18V8.712.778.9514.95115.17-87.7421.90-3.8214.37314.064跨间M________53.3049.4851.5640.2848.5946.62M________2.582.5845.3642.638.638.08注:表中和分别为AB跨和BC跨的跨间最大正弯矩。M以下部受拉为正,V以向上为正。M单位为KN/m,N单位为KN104
下面以第一层BC跨梁考虑地震作用的组合为例,说明各内力的组合方法。对支座负弯矩按相应的组合情况进行计算,求跨间最大正弯矩时,可根据梁端弯矩组合及梁上荷载设计值,由平衡条件确定。由图可得VB=-(MB+MC)/l+1/2q1l+(1-a)q2l/2若VB-1/2(2q1+q2)al≤0,说明x≤al,其中x为最大正弯矩截面至B支座的距离,则x可由下式求解:VB-q1x-0.5q2x2/al=0将求得的x值代入下式即可得跨间最大正弯矩Mmax=MB+VBx-q1x2/2-q2x3/6al若VB-1/2(2q1+q2)al≥0,说明x≥al,则x=(VB+q2al/2)/(q1+q2)Mmax=MB+VBx-(q1+q2)x2/2+q2al(x-al/3)/2若VB≤0,则Mmax=MB同理,可求得三角形分布荷载和均布荷载作用下的VB、x和Mmax的计算公式VB=-(MB+MC)/l+1/2q1l+(1-a)q2l/4x由下式解得q1x+q2x2/l=VBMmax=MB+VBx-q1x2/2-q2x3/3al7.2.3框架柱内力组合取每层柱顶和柱底两个控制截面按相应的方法进行组合,组合结果及柱端弯矩设计值的调整见表7-6到表7-11。104
表7-6横向框架柱A柱弯矩和轴力组合表层次截面位置内力NMM→←→←9柱顶M44.8017.0822.2216.88217.13-10.0279.0951.00105.86107.12217.1351.00217.13N234.2845.294.354.41354.30285.33224.93216.30343.56325.26354.30216.30354.30柱底M-28.16-6.499.525.63-4.82-102.17-24.95-40.06-53.76-55.65-4.82-40.06-4.82N253.1445.294.354.41387.24318.27249.63241.01380.62358.2387.24241.01387.248柱顶M25.255.9734.6117.01122.11-45.4447.49-2.6337.8040.13122.11-2.63122.11N516.3691.5513.1712.91794.85638.06513.48484.23773.55727.34794.85484.23794.85柱底M-30.31-7.1921.399.1613.43-98.29-17.73-31.70-41.74-44.4413.43-31.7013.43N542.8591.5513.1712.91827.80671.00538.18508.93810.60760.28827.80508.93827.807柱顶M30.317.1945.3330.42118.44-23.1861.34-4.1947.5649.65118.44-4.19118.44N798.44137.727.1626.801232.4993.95807.75746.421203.541129.431232.24746.421232.24柱底M-32.91-7.1935.3320.286.84-101.80-21.21-35.78-47.41-49.506.84-35.786.84N832.56137.727.1626.801265.21026.89832.45771.131240.601162.371265.18771.131265.186柱顶M32.917.1956.3939.68103.88-15.6767.62-14.8643.9746.00103.88-14.86103.88N1080.5183.946.7846.371665.41354.051107.71002.31633.531531.511665.431002.931665.43柱底M-32.38-7.1946.1432.473.49-94.336.50-60.97-45.34-47.353.49-60.973.49N1122.3183.946.7846.371698.41386.991132.421027.31670.581564.451698.371027.631698.375柱顶M32.387.1956.0749.98108.76-11.4977.82-19.6848.4750.73108.76-19.68108.76N1361.8211.569.4369.742112.041735.041423.441269.12082.821950.762112.041269.412112.04柱底M-37.56-5.9045.8840.89-0.60-98.9719.17-78.33-49.46-51.97-0.60-78.33-0.60N1431.5211.569.4369.742151.31774.251452.851298.22126.931989.962151.241298.822151.244柱顶M28.045.9061.6959.0989.54-5.0379.45-28.9742.1044.0889.54-28.9789.54N1639.0249.096.7796.502558.52128.781747.941536.22539.162376.262558.441536.522558.44柱底M-36.78-8.5550.4759.09-8.03-85.4226.29-82.13-32.43-31.44-131.1187.35-32.43N1740.7249.096.7796.502597.72167.981777.341565.21759.381663.861440.32938.561759.383柱顶M26.416.1864.5665.7270.9811.2883.44-34.3230.4629.53153.84-112.7330.46N1916.47287.33127.86128.632998.472528.871978.421897.52777.261965.191741.711071.242077.26柱底M-27.03-7.1552.8365.72-19.60-79.2929.46-88.30-32.40-31.40-155.15111.43-32.40N2049.96287.33127.86128.633037.682568.072007.821927.52121.372004.401773.071102.612121.372柱顶M25.187.6865.4871.3753.9315.2296.78-55.5129.8228.91148.07-107.8329.82N2194.32325.79161.75159.843445.912949.422419.592068.82439.222306.752082.141227.622439.22柱底M-18.04-7.1565.4871.37-20.98-62.70165.33-19.05-32.52-31.53-178.32134.45-32.52N2382.11325.79161.75159.843498.693002.202459.172108.62483.332345.962113.511258.982483.331柱顶M27.547.7343.9254.6835.4618.54123.48-62.1424.3922.77119.80-88.1123.49N2494.54364.17193.03194.633907.452234.512897.242456.72809.372655.562426.481391.802809.37柱底M-9.02-3.56119.9127.6-23.41-53.24180.42-60.78-11.76-11.40-451.14435.28-11.76N2526.87364.17193.03194.633896.733459.892874.352347.92902.142492.452492.451457.772902.14注:表中M以左侧受拉为正,单位kN/m。N以受压为正,单位kN。一列中括号内的数值为屋面雪荷、其他楼层面作用活荷对应的内力值104
表7-7横向框架B柱柱端组合弯矩设计值的调整截面γRE(ΣMc=ηcMb)γREN柱顶柱顶____柱底____柱底柱顶____柱底____7柱顶127.26768.42柱底79.61546.986柱顶110.89746.42柱底90.56771.135柱顶126.391002.93柱底123.651027.634柱顶121.851269.41柱底130.741298.823柱顶132.891536.52柱底156.481565.922柱顶100.391897.65柱底178.691927.051柱顶100.391897.65柱底178.691927.05104
层次SGkSQkSWkSEk1.2SGk+1.26(SQk+SWk)gRE[1.2(SGk+0.5SQk)+1.3SEk)1.35SGk+SQk1.2SGk+1.4SQkgRE[ηvb(Mlc+Mrc)/Hn]→←→←9-15.18-6.168.1428.7-22.36-30.5616.89-51.30-28.63-27.9455.168-14.69-4.3914.3645.98-13.56-33.5848.96-67.56-23.56-22.6375.437-13.85-3.2920.6855.36-10.36-39.1535.46-82.30-25.14-24.55117.356-12.96-3.9626.2968.37-4.96-40.3664.37-92.12-21.68-19.84130.485-13.01-3.9726.1474.96-3.68-45.9770.45-102.33-20.69-20.01144.574-13.45-3.8828.7683.65-2.94-46.3378.65-109.54-22.33-21.47150.553-11.97-3.0530.1090.86-8.01-50.64-86.87-115.32-19.56-18.88162.582-6.28-2.0433.58113.432.15-49.86120.34-128.44-8.13-7.17190.411-4.65-1.0439.02132.750.65-40.67153.84-136.27-6.91-6.70227.50表7-8横向框架B柱剪力组合104
表7-9横向框架柱C柱弯矩和轴力组合表层次截面位置内力NMM→←→←9柱顶M-19.15-8.6519.8132.80187.55-253.576.3695.73105.86107.12217.1351.00217.13N250.4263.134.6010.54413.43279.495240.77223.67343.56325.26354.30216.30354.30柱底M24.075.0011.8323.75158.26-100.7937.530.28-53.76-55.65-4.82-40.06-4.82N257.5863.134.6010.54446.37312.43265.48248.38380.62358.2387.24241.01387.248柱顶M-29.30-5.5230.4060.49150.18-199.4133.576-66.2637.8040.13122.11-2.63122.11N555.92124.5414.8640.09977.63651.44585.39525.92773.55727.34794.85484.23794.85柱底M27.624.9518.1649.49151.1082-102.1556.949-24.75-41.74-44.4413.43-31.7013.43N589.05124.5414.8640.091010.57684.38610.10550.62810.60760.28827.80508.93827.807柱顶M-27.62-3.1256.1282.74122.613-174.4150.86-85.2447.5649.65118.44-4.19118.44N862.82158.6834.4285.801531.531033.707942.86815.331203.541129.431232.24746.421232.24柱底M25.523.0133.5373.14146.44-96.5876.65-44.04-47.41-49.506.84-35.786.84N920.53158.6834.4285.801564.471066.64967.57840.041240.601162.371265.18771.131265.186柱顶M-25.52-5.5374.71103.5696.1578-152.41566.49-104.3243.9746.00103.88-14.86103.88N1169.72210.4863.69146.042076.131425.2711311.571093.511633.531531.511665.431002.931665.43柱底M24.105.3144.6391.83134.39-86.053891.98-59.53-45.34-47.353.49-60.973.49N1252.00210.4863.69146.042109.061458.1991336.271118.201670.581564.451698.371027.631698.375柱顶M-24.10-5.3188.3095.5572.56-122.83662.16-95.5848.4750.73108.76-19.68108.76N1466.08253.64101.08207.32616.001839.4961688.2021377.2162082.821950.762112.041269.412112.04柱底M21.304.6978.3195.55102.23-57.629493.552-64.203-49.46-51.97-0.60-78.33-0.60N1596.18253.64101.08207.32655.2121878.71717.6051406.6192126.931989.962151.241298.822151.244柱顶M-27.59-6.08116.58106.8646.549-93.159672.651-103.62942.1044.0889.54-28.9789.54N1762.44296.80161.77271.943141.8452280.2832071.1421664.0022539.162376.262558.441536.522558.44柱底M21.274.69103.38106.8691.383-48.3258102.2025-74.0775-46.56-48.74-8.03-82.13-8.03N1904.44296.80161.77271.943137.952276.3952068.2261661.0862583.272415.472597.641565.922597.643柱顶M-29.90-6.59134.23125.7026.406-78.75986.046-121.43440.9742.9070.98-34.3270.98N2062.00339.92237.90344.883660.892728.1442461.7661943.322995.502801.772998.471897.652998.47柱底M26.835.70119.04102.8431.266-54.766874.052-95.59-49.16-51.61-19.60-88.30-19.60N2284.64339.92237.90344.883700.152767.3482491.161972.733039.602840.983037.681927.053037.682柱顶M-24.64-5.37155.4788.4815.31-59.0532112.86-150.8634.4336.0853.93-55.5153.93N2363.74382.98327.99400.093431.312454.2572505.431862.803467.513241.213445.912068.983445.91柱底M19.509.5440.63144.3574.262-28.125230.96-198.42-20.74-21.79-20.98-190.15-20.98N2447.58382.98327.99400.093484.082507.0332545.011902.313526.893293.993498.692108.563498.691柱顶M-9.79-3.885.63130.285.76-38.54153.21223.387.8224.6434.11-72.5638.33N2663.43426.07410.93490.483510.312145.872654.632138.423565.733633.873854.332347.663845.21柱底M5.651.9446.42250.66102.31-6.87459.47-448.88-15.62-15.04-25.87-244.56-25.67N2763.28426.07410.93490.483564.202012.642678.922326.714021.543662.123893.772431.603876.32注:表中M以左侧受拉为正,单位kN/m。N以受压为正,单位kN。一列中括号内的数值为屋面雪荷、其他楼层面作用活荷对应的内力值104
表7-10横向框架C柱柱端组合弯矩设计值的调整层次截面γRE(ΣMc=ηcMb)γREN9柱顶____柱底____8柱顶____柱底____7柱顶200.691232.24柱底205.471265.186柱顶230.451665.43柱底230.581698.375柱顶260.892112.04柱底300.252151.244柱顶270.692558.44柱底310.522597.643柱顶289.402998.47柱底312.413037.682柱顶302.323325.71柱底325.723476.231柱顶258.473445.91柱底633.113898.69104
层次SGkSQkSWkSEk1.2SGk+1.26(SQk+SWk)gRE[1.2(SGk+0.5SQk)+1.3SEk)1.35SGk+SQk1.2SGk+1.4SQkgRE[ηvb(Mlc+Mrc)/Hn]→←→←915.075.288.2045.4430.0215.3968.78-50.2421.3620.7480.69814.394.9712.4596.3936.055.8998.47-74.8823.6923.04120.35714.563.5822.99116.2543.74-8.47121.30-100.2522.1421.69180.56612.133.2030.60135.5648.34-18.97146.35-123.1519.4718.75204.17511.233.4432.69148.7456.38-25.64167.58-150.2617.4816.89235.58410.122.8838.46160.5961.30-32.15180.69-162.5817.2316.52260.58310.122.2440.37168.2565.56-39.48190.28-171.7418.4517.63264.7825.551.9840.26140.2157.13-46.58163.58-163.986.856.13240.2212.980.7634.47129.7547.21-39.56156.86-156.574.604.43212.78表7-11横向框架C柱剪力组合104
第8章截面设计8.1框架梁这里仅以第一层BC跨梁为例,说明计算方法和过程,其它层梁的配筋计算结果见表8-1和表8-2。从表7-5中分别选出BC跨跨间截面及支座截面的最不利内力,并将支座中心处的弯矩换算为支座边缘控制截面的弯矩进行配筋。支座弯矩:跨间弯矩取控制截面即支座边缘撤的正弯矩,由表7-5可求得相应的剪力:则支座边缘处:当梁下部受拉时,按T型截面设计,当梁上部受拉时,按矩形截面设计,翼缘计算宽度当按跨度考虑时104
按梁间距考虑时按翼缘厚度考虑时此种情况不起控制作用。故取梁内纵向钢筋选HRB400级钢,下部跨间截面按单筋 T型截面计算。因为属第一类T型截面,实配钢筋,4φ20(As=1256)满足要求。将下部跨间截面的4φ20钢筋伸入支座,作为支座负弯矩作用下的受压钢筋(),再计算相应的受拉钢筋As,即支座B上部104
说明As富裕,且达不到屈服,可近似取,实取5φ20(As=1570)支座上部 实取5φ20(As=1570), ,满足要求。8.2.2梁斜截面受承载力计算BC跨:故截面满足要求箍筋加密区4φ8@100,箍筋用HPB235级钢筋。则加密区长度取0.90m,非加密区取箍筋箍筋加密区取4肢φ8@150,箍筋设置满足要求。CD跨:若梁端箍筋加密区取4肢φ10@100,则其承载力为=385.09kN>γV=215.99kN由于非加密区长度较小,故全跨均可按加密区配置。104
表8-1框架梁纵向钢筋计算表层次截面MkN·mζ,mm2,mm2实配钢筋As,mm2ρ%9支座B-130.2<0604703416(804)0.750.47-127.7<0604650416(804)0.750.47BC跨间103.20.008__462316(603)__0.36支座Cr-51.21<0402444316(603)0.670.55CD跨间45.220.03__356216(402)__0.375支座B-260.6<010171381520(1570)0.650.79-245.5<010171321520(1570)0.650.79BC跨间168.70.012__825418(1017)__0.51支座Cr-136.4<01017713520(1570)0.651.23CD跨间126.910.064__1003418(1017)__0.81支座B-255.02<010171337520(1570)0.650.79-239.11<010171253520(1570)0.650.79BC跨间179.410.013__896418(1017)__0.51支座Cr-128.7<01047690520(1570)0.651.23CD跨间120.20.06__960418(1017)__0.8104
表8-2框架梁箍筋数量计算表层次截面kNkN梁端加密区非加密区9B、116.5566.1>γRE2φ8@100(1.01)2φ8@150(0.224)Cr83.81365.7>γRE2φ8@100(1.01)2φ8@150(0.224)5B、194.06755.4>γRE4φ8@100(2.01)4φ8@150(0.383)Cr240.91488.0>γRE4φ8@100(2.01)4φ8@150(0.383)1B、183.38755.4>γRE4φ8@100(2.01)4φ8@150(0.383)Cr215.99488.0>γRE4φ8@100(2.01)4φ8@150(0.383)注:表中V为换算至支座边缘处的梁端剪力。8.2框架柱8.2.1剪跨比和轴压比验算表8-3计算出了框架柱各层剪跨比和轴压比计算结果,其中剪跨比λ也可取,表中的,和N都不应考虑承载力抗震调整系数。由表可知,各柱的剪跨比和轴压比均满足规范要求。104
表8-3柱的剪跨比和轴压比验算柱号层次Bmmh0mmN/mm2MckN·mkNNB柱955051014.3133.0775.151096.883.16>20.182<0.8560056014.3178.56113.073205.542.82>20.533<0.8170066016.7418.8122.754689.735.17>20.502<0.8C柱955051014.3166.2191.61901.773.24>20.150<0.8560056014.3263.23157.624384.772.98>20.729<0.8170066016.7441.51138.096435.964.84>20.688<0.88.2.2柱正截面承载力计算以第二层C轴柱为例,根据C柱内力组合表,将支座中心处的弯矩换算至支座边缘,并与柱端组合弯矩的调整值比较后,选出最不利内力,进行配筋计算。C节点左、右梁端弯矩-403.99+214.74×0.7/2=-328.83kN·m226.44-183.01×0.7/2=162.39kN·mC节点上、下柱端弯矩401.73-174.2×0.12=380.83kN·m-205.88+138.09×(0.6-0.12)=-139.60kN·m104
在节点处将其按弹性弯矩分配给上下柱端,即取20mm和偏心方向截面尺寸的1/30两者中的较大值,即600/30=20mm。故取柱的计算长度按公式(8-1)(8-2)确定其中,因为故应考虑偏心距增大系数。取取104
对称配筋为大偏心情况=-544.16<0再按及相应的M一组计算N=4503.24kN节点上、下柱端弯矩68.33-29.91×0.12=64.74kN·m41.87-13.95×(0.6–0.12)=35.17kN·m此组内力是非地震组合情况,且无水平荷载效应,故不必进行调整,且取因为故应考虑偏心距增大系数。取取104
故为小偏心受压按上式计算时,应满足N>及Ne>0.43fcbh02.因为N=5096.19kN<=0.518×14.3×600×560=2488.89kN且Ne=5096.19×103×372.21=1896.85kN·m<0.43fcbh02=0.43×14.3×600×5602=2504.31kN·m故按构造配筋,且应满足ρmin=0.8%,单侧配筋率ρsmin≥0.2%,故选520(As=As’=1570㎜2)总配筋率为8.2.3柱斜截面受剪承载力计算由前可知,上柱柱端弯矩设计值Mct=158.06kN·m对二级抗震等级,柱底弯矩设计值Mcb=1.25×441.51=551.89kN·m则框架柱的剪力设计值:104
(满足要求)取其中Mc取较大的柱下端值,而且Mc、Vc不应考虑γRE故Mc为将表查得的值除以0.8,Vc为将表查得的值除以0.85与Vc相对应的轴力。N=4107.14KN>0.3fcbh02=0.3×19.1×7002/103=2807.7kN故该层柱应按构造配置钢筋。柱端加密区的箍筋选用4φ10@100。由表可得一层柱底的轴压比由表查得λv=0.10则最小体积配箍率取φ10,Asv=78.5mm2,则S≤151.5mm根据构造要求,取加密区箍筋为4φ10@100加密区位置及长度按规范要求确定。非加密区还应满足,故箍筋取4φ10@200各层柱箍筋计算结果见表8-4。104
表8-4框架柱箍筋数量表柱号层次γREKN0.2fcβcbh0KNNKN0.3fcAKNAsv/smmλvfc/fyv实配箍筋(ρv%)加密区非加密区B柱990.111122.2>V672.91803.6<00.4454φ8@100(0.73)4φ8@150(0.48)5155.951764.8>V3710.22807.7<00.5794φ10@100(0.97)4φ10@150(0.64)1150.241764.8>V4175.42807.7<00.6434φ10@100(0.97)4φ10@150(0.64)C柱9120.131122.2>V672.561803.6<00.4454φ8@100(0.73)4φ8@150(0.48)5200.121764.8>V2997.22807.7<00.6754φ10@100(0.97)4φ10@200(0.49)1173.371764.8>V3341.72807.7<00.7514φ10@100(0.97)4φ10@200(0.49)8.3节点设计根据地震震害分析,不同烈度地震作用下钢筋混凝土框架节点的破坏程度不同,7度地震时,未按抗震设计的多层框架结构节点较少破坏,在8度时,部分节点尤其是角柱节点发生程度不同的破坏。在9度以上地震作用下,多数框架节点产生严重震害。因此,对不同的框架,应有不同得节点承载力和延性要求。《建筑结构抗震规范》[1]规定,对一,二级抗震等级的框架节点必须进行受剪承载力计算。而三级抗震等级得框架节点,仅按构造要求配箍。不再进行受剪承载力计算。对于纵横向框架共同具有得节点,可以按各自方向分别进行计算。下面以第一层横梁与B柱相交得节点为例,进行横向节点计算。8.3.1节点核心区剪力设计值对于二级框架:104
(8-3)式中—节点核心区组合的剪力设计值;—与柱弯矩调整公式中意义相同。—柱的计算高度,可以取节点上下柱反弯点间得距离;—节点两侧梁的平均高度;—节点两侧梁有效高度平均值。8.3.2节点核心区截面验算在节点设计中,首先要验算节点截面的限制条件,以防节点截面太小,核心区混凝土承受过大斜压应力致使节点混凝土先被压碎而破坏。框架节点受剪水平截面应符合如下条件:(8-4)式中bj—节点水平截面得宽度,当验算方向得梁截面宽度不小于该侧柱截面宽度的一半时,取等于框架柱的宽度;hj—框架节点水平截面高度,可采用验算方向得柱截面高度;ηj—交叉梁对节点约束的影响系数,当四侧各梁截面宽度不小于该侧柱截面宽度得一半;—按受剪构件取值。满足要求。104
8.3.3节点核心区截面抗剪强度验算设计表达式为:(8-5)框架节点的受剪承载力由混凝土斜压杆和水平筋两部分受剪承载力组成。公式中考虑了轴向力对抗剪能力的提高,但是当轴压比大到一定程度后,节点受剪能力不再随着轴压比的增大而增加,甚至有所下降。故限制公式中轴压力设计值的取值不应大于;当节点再两个正交方向有梁时,梁对节点区混凝土有一定约束作用,提高了节点的受剪承载力,再公式中用来考虑这一影响,但对梁截面较小或只有一个方向有梁的节点以及边节点,交节点,由于约束作用不明显,均不考虑这一影响。式中:—取对应于剪力设计值的上柱轴压力;—核心区验算宽度范围内箍筋总截面面积,由下式计算:(8-6)满足要求。8.4构造要求8.4.1梁的构造1.截面尺寸框架梁得截面尺寸一般由三个条件确定:104
1)最小构造截面尺寸要求;2)抗剪要求;3)受压区高度的限值。框架梁的截面高度hb一般按(1/8~1/12)lb(lb为梁的计算跨度)估且不宜大于1/4净跨,梁得高宽比不宜小于0.25,因为当高宽比较小时,混凝土抗剪能力有较大的降低,同时梁截面宽度不宜小于200mm和1/2bc(bc),梁截面得最小尺寸还应满足竖向荷载作用下的刚度要求。2.梁的纵向钢筋抗震要求时:1)纵向受拉钢筋配筋率不应小于如下数值抗震设计时,框架梁纵向受拉钢筋最小配筋率百分率抗震等级支座跨中一0.400.30二0.300.25三、四0.250.202)考虑到水平力产生得剪力在框架梁总剪力中占的比例较大,且水平力往复作用下,梁中剪力反号,反弯点移动得因素,在框架梁中不采用弯起钢筋,梁中全部剪力由箍筋和混凝土共同承担。3)梁截面上部和下部至少分别配置两根贯通全跨得钢筋,一、二级框架梁其直径不小于14mm,且不应小于梁端顶面和底面纵向钢筋中较大截面得1/4,三、四级框架梁纵筋直径不小于12mm。4)在地震反复荷载作用下,梁中纵向钢筋埋入柱节点的相当长度范围内,混凝土与钢筋得黏结力易发生破坏,因此,应比非抗震框架得锚固长度大。一级框架104
二级框架三、四级框架5)一、二级框架梁纵向钢筋应伸过柱节点中心线。当纵向钢筋再节点内水平锚固长度不够时,应沿柱节点外边向下弯折。试验研究表明,伸入支座弯折锚固的钢筋,锚固力由弯折钢筋水平段的黏结强度和垂直段的弯折锚固作用所构成。水平段得黏结是构成锚固得主要成分,它控制了滑移和变形,在锚固中起很大作用,故不应小于0.45lAe。垂直段只在滑移变形较大时才受力,要求垂直段不小于10d,因随垂直段加长,其作用相对减小。故限制垂直段长度为22d。3.梁的箍筋1)箍筋应做1350弯钩,弯钩端头直段不应小于10d(d为箍筋直径)。2)试验表明,当纵向钢筋屈服区内配置箍筋间距小于6d~8d(d为纵直径)时,在压区混凝土彻底崩溃前,压筋一般不会发生压曲现象,能充分发挥梁的变形能力。为此规定了梁的加密区长度,箍筋最大间距及最小直径,见表8-5表8-5梁加密区长度、箍筋最大间距和最小直径(mm)抗震等级加密区长度(取较大值)箍筋最大间距(取较小值)箍筋最小直径一2,500/4,6d,100φ10二1.5,500/4,8d,100φ8三1.5,500/4,8d,150φ8四1.5,500/4,8d,150φ6注:d为纵筋直径,为梁高。非加密区箍筋间距不应大于/2,bb及250mm3)加密区箍筋的支距,一、二级不应大于200mm,三、四级不宜大于104
200mm。纵向钢筋每排多于4根时,每隔一根宜用箍筋或拉筋固定,梁端第一箍筋距离柱边一般为50mm。4)沿梁全长,箍筋得配筋率不应小于下列规定:一级抗震二级抗震三级抗震8.4.2柱的构造1.柱截面尺寸框架柱截面尺寸一般由三个条件确定:1)最小构造截面尺寸要求;2)轴压比的要求;3)抗剪要求。由构造要求,框架柱截面高度hc不宜小于400mm,柱截面宽度不宜小于300mm,hc/bc不应超过1.5,应尽量采用方柱。2.柱的纵向钢筋1)框架柱宜采用对称配筋以适应水平荷载和地震作用正反两向的要求。2)框架柱纵向钢筋最大配筋率(包括柱中全部配筋)设计时不应104
小于4%,在搭接区段内不应大于5%;当柱净高与截面有效高度之比为3~4时,其纵向钢筋单边配筋率不宜超过1.2%,并沿柱全长采用复合箍筋。3)为保证柱得延性,框架柱中全部纵向钢筋截面面积与柱有效面积之比不应小于。见表8-6表8-6框架柱纵向钢筋最小配筋率百分率类别构件非抗震设计抗震设计一二三四中柱、边柱0.4080.70.605角柱0.41.00.90.80.74)框架柱中纵向钢筋间距不应过大,以便对核心混凝土产生约束作用。抗震设计时不应大于200mm。5)纵向钢筋的接头,一级框架应采用焊接接头,二级框架底层应采用焊接接头,其他也采用焊接接头,三级框架可采用搭接接头,但底层采用焊接接头。纵向钢筋接头应避开柱端加密区,同一截面内的接头钢筋面积不宜大于总面积的1/2,相邻接头间距,焊接时不小于500mm,搭接时不小于600mm,接头最低点距离楼面至少750mm,并不小于柱截面长边尺寸。6)纵筋的搭接长度在一级抗震时不小于,二级时不小于;三、四级时不小于。7)框架顶层柱得纵向钢筋锚固应在柱顶或伸入梁板内,其长度自梁底面算起为。抗震设计时,一级不小于;二级时不小于;三、四级时不小于;且至少有10d以上的直钩长度。3.柱的箍筋1)柱箍筋应采用复合箍筋,当每边纵筋大于或等于4根时,宜采用井字型箍筋,有抗震要求时,纵筋至少每隔一根有箍筋或拉筋拉接,以固定其位置,并使纵筋在两个方向都有约束。104
2)柱箍筋得肢距不宜大于200mm,为保证箍筋能在核心混凝土内锚固,在地震荷载作用下,混凝土保护层脱落后钢筋仍不散开,继续约束核心混凝土。箍筋应做1350弯钩,弯钩端头直段不小于10d(d为箍筋直径)。3)柱端箍筋加密区范围为:截面高度、柱净高的1/6和450mm三者中的较大值,对底层柱底,取刚性地面上下各500mm。一级框架角柱以及任何框架中得短柱,需要提高变形能力的柱,沿全高加密箍筋。4)加密区箍筋最大间距及最小直径应满足表8-7的要求。表8-7加密区箍筋最大间距及最小直径(mm)抗震等级箍筋最大间距(采用较小值)箍筋最小直径一6d,100φ10二8d,100φ8三8d,150φ8四8d,150φ6框架柱,截面尺寸不大于400mm时,箍筋最小直径可采用φ6;角柱、短柱箍筋间距不应大于100mm。5)柱加密区箍筋的体积配筋率,应满足表8-8中的要求(体积配筋率;为混凝土体积;为在内箍筋的体积)。104
表8-8柱加密区箍筋最小体积配筋率(%)抗震等级箍筋形式柱轴压比<0.40.4~0.6>0.6一普通、复合0.81.21.6一螺旋箍0.81.01.2二普通、复合0.6~0.80.8~1.21.2~1.6螺旋箍0.60.8~1.01.0~1.2三普通、复合0.4~0.60.6~0.80.8~1.2螺旋箍0.40.60.8注:计算箍筋体积配筋率时,不计算重合部分箍筋体积。6)非加密区的箍筋不应小于加密区箍的50%,为施工方便,宜不改变直径而将间距扩大一倍,但对一、二级抗震,间距不宜大于10d,三级不宜大于15d(d为纵筋直径)。7)纵向钢筋搭接接头处,箍筋间距应符合以下要求:纵筋受拉时,不大于5d及100mm纵筋受压时,不大于10d及200mm8.5楼梯计算本工程楼梯为现浇整体板式楼梯,踏步尺寸150mm×300mm,标准层层高3900mm,底层层高4200mm;采用混凝土强度等级C25,板采用HPB235级,梁采用HRB400级钢筋;楼梯上均布活荷载标准值q=2.0kN/m2。104
8.5.1计算简图8-1的确定图8-1楼梯计算简图8.5.2梯段板计算取板厚H=120mm,约为板斜长的1/30。板倾斜角tanα=140/280=0.5,cosα=0.894。取1m宽板带计算。1荷载计算恒载:104
20厚花刚石楼板20厚水泥砂浆找平层三角形踏步重1/2×0.3×0.15×25/0.3=1.88kN/m混凝土斜板0.12×25/0.894=3.36kN/m板底抹灰0.02×17/0.894=0.38kN/m恒荷载标准值=6.72kN/m恒荷载设计值=1.2×6.72=8.06kN/m活荷:活荷载标准值=2.25kN/m恒荷载设计值=1.4×2.5=3.5kN/m恒荷载分项系数:活荷载分项系数。总荷载设计值P=8.06+3.5=11.56kN/m2截面设计板水平计算跨度ln=3.9m,弯距设计值:。板的有效高度h0=120-20=100mm查表选配分布筋每级踏步,As=714mm2另每级踏步下配一根6分步筋。104
8.5.3平台板设计设平台板厚H=80mm,取1m宽板带计算。1.荷载计算恒荷载:20厚花岗石楼面0.02×15.4=0.3kN/m20厚水沙浆找平层0.02×20=0.4kN/m平台板0.8×25=2.0kN/m板底抹灰0.02×17=0.34kN/m荷载标准值=3.04kN/m恒荷载设计值=1.2×3.04=3.65kN/m活荷载:活荷载标准值=2.5kN/m恒荷载标准值=1.4×2.5=3.5kN/m总荷载设计值P=3.65+3.5=7.15kN/m2.截面设计平台板的计算跨度l0=2.2m。弯距设计:板的有效高度h0=80-20=60mm查表104
选配,As=402mm28.5.4平台梁设计平台梁截面尺寸为300×400mm21.荷载计算平台板的荷载计算梯板传来11.56×3.3/2=19.07kN/m平台板传来7.15×(0.3+1.9/2)=8.94kN/m梁自重1.2×0.3+(0.3+0.4×2-0.08×2)×17=2.88kN/m梁粉刷1.2×0.02×(0.3+0.4-0.08×2)×17=0.384kN/m总荷载设计值P=34.73kN/m2.截面设计计算跨度:弯距设计值:剪力设计值:截面按倒L型计算:梁的有效高度:。经判断属第一类T型截面104
查表选配可按构造配筋,箍筋箍筋,则斜截面受剪承载力:满足要求。8.6板的设计8.6.1楼面板②区格板图8-2楼面板②区格板104
将上列各值代入下式,得:配筋计算:,采用混凝土,,,采用HPB235级钢筋。方向跨中:104
所以,选用,。方向支座配筋:所以,选用,。方向跨中:所以,选用,。方向支座配筋:选用,。验算适用条件:,满足要求。104
且,满足要求。8.6.2楼面板D区格板图8-3楼面板D区格板104
将上列各值代入下式,得:配筋计算:,采用混凝土,,,采用HPB235级钢筋。方向跨中:所以,选用,。方向支座配筋:104
=0.00365=0.998所以,选用,。方向跨中:=0.994所以,选用,。104
结论通过这次毕业设计,我对结构设计有了更加深刻的认识,对框架结构设计也有了较深刻和全面的认识和了解。此次框架结构设计的步骤如下:①根据场地条件和功能要求,进行结构布置,确定柱网和梁柱尺寸的初步尺寸;②考虑多种荷载,恒荷载和活荷载,考虑要周全,比如抗震设计和风荷载的计算,接着要明确荷载传递路径,画出计算简图;③然后进行框架结构内力分析,对竖向荷载作用下内力计算采用二次弯矩分配法,对水平荷载作用下,采用D值法;④最后画结构施工图,这时需要充分了解构造要求,如箍筋加密区,纵筋搭接,截断和锚固等等。设计中所遵循的原则:①强柱弱梁②强剪弱弯104
致谢在完成本设计过程中,我们得到了指导教师的大力帮助,在接近三个月的设计中,指导教师带领我们设计,每当有问题时老师的身影就会及时出现,为我们答疑解惑,可以说正是由于指导教师才能是我们及时并圆满的完成任务,在此我仅代表我个人及我组的成员向我们的指导教师及建筑工程教研室的所有老师说声谢谢!。在此,我尤其要感谢姜封国老师,感谢他对我的耐心的指导。在此也感谢院校为我们大四的毕业生提供的这次锻炼机会,我们即将完成学业,离开母校,带着四年的知识硕果投身到自己的工作岗位,大学四年美好的生活与学习将成为我们生命的重要历程。对于我们大四的每位毕业生来说,都希望"今天我以黑龙江科技学院为骄傲,明天黑龙江科技学院以我为自豪"。104
参考文献1中华人民共和国国家标准.建筑设计抗震规范(GB50011—2001).北京:中国建筑工业出版社,20012中华人民共和国国家标准.混凝土结构设计规范(GB50010—2002).北京:中国建筑工业出版社,20023中华人民共和国国家标准.建筑结构荷载规范(GB50009—2001).北京:中国建筑工业出版社,20014中华人民共和国国家标准.高层建筑混凝土结构技术规程(JGJ3—2002).北京:中国建筑工业出版社,20025中华人民共和国国家标准.高层民用建筑设计防火规范(GB50045—95).北京:中国建筑工业出版社,19956中华人民共和国国家标准.民用建筑设计通则(JGJ37—87).北京:中国建筑工业出版社,19877吕西林.高层建筑结构设计.武汉理工大学出版社,20038同济大学等.房屋建筑学.同济大学出版社,19979龙驭球,包世华.结构力学.高等教育出版社,199410武汉工业大学.建筑工程专业英语教程.武汉工业大学出版社,199511李廉锟.结构力学.高等教育出版社,199512严正庭.混凝土结构实用构造手册.中国建筑工业出版社,199713曹双寅.工程结构设计原理.东南大学出版社,200214陈希哲.土力学地基基础.清华大学,199615HuangWX,ChenXZ.TheTigerHillPagodaofSuzhou.Beijing:ThePisaofChina,1981104
附录1张拉结构的特性在张拉结构中,主要的荷载承受构件将荷载传给基础或其他支撑构件,受力特点是通过直接张拉应力而不是弯曲或压缩.他们的横截面积和构造是可以忽略的,由于他们的剪力和弯曲刚度,还有他们的咬结抵抗力,一般抗拉结构可分为两大类:缆式结构,它是由轴向应力构件组成;膜结构,是由应力构件组成的.缆式结构一般能被区分为四个类型:(1)缆式构件是由单一缆式构件组成,或者由一些简单的构件组成,它主要是在一个单一的平面内承受主要荷载,举例来说,悬缆式,链栓线或者停泊线,用于塔或者帐篷的支锁构件.(2)缆式框架中的预应力构件被连接在同一个平面内,荷载也在同一个平面内,例如,缆式桥梁和双层缆支撑屋面.(3)在缆式网中的缆部构件被成倍的连接在曲面内(塑性或者非塑性),荷载作用于主要承受荷载的平面内,例如,悬吊屋架和悬挂网架.(4)在缆网工程的构件中,绳索被连接在一个三维空间的结构,举例来说,悬挂网架,管道网,多肢腿系统.薄膜结构的又有四个类型:(1)空气支援的结构,它周围的密集的薄膜被压缩的空气(或液体)压力支撑,举例来说,规距仪盖屋顶,临时膨胀庇护所或仓库.(2)在一个大空间结构当中,高压管道和双重墙体当成它的构件的一部分,膨胀结构高度地高压管或双重的-墙壁垫在大空间结构中被当作结构的成员使用,举例来说,有膨胀柱体杆件,大柱体或拱门;双重的-墙壁壳;气垫屋顶.104
(3)预应力薄膜或像纤维类的张超过硬的结构,被伸展形成横隔膜,用来制作很多构件,举例来说,比如帐篷和天线屋顶.(4)薄膜嵌板,在此中结构中,索膜板位于主要承受荷载的构件之间,例如预应力缆结构和刚性构件等等,又如,预应力织物状屋顶,液体储藏槽.因为张拉结构的那固有的非线性性质,传统的线性分析是这样的:小的塑性变形和偏移,在索膜结构和缆式结构中应用不是很广泛.在过去二十年期间,张拉结构在分析方法上和和计算机编程密码有了相当的发展.相对比较便宜的技术方法和计算机编程必须为初步设计作好选择和合理的安排,也为设计理念的更新进化作好选择.在开始设计方案被选择定下来并且进行细部分析,详细说明之後,精炼的分析程序一定要用来评估非线性动态反映,要对可以预见的和极限荷载都做到充分的考虑和预测.1.张拉结构的应用张拉结构在对活荷载和恒荷载的受力分配当中起着很好的作用,对受力分配非常有利,例如,对于风荷载,海洋旋涡流压力,和由波浪运动引起的推移力,这些荷载都可以通过构件的表面和纤维承担.还有一些对使用张拉结构有利的结构如下所述:(1)他们是轻质的和可折叠的,因此容易的运输和直立起来.(2)们能在工厂中可以被提前预制成,因此只需很低的安装施工费用,和重新分配搬运费用.(3)对于空气支撑的结构,主要的负荷机制是自身居住荷载和周围环境,例如,有很强压力的气体混合物.(4)环境的负荷可以被有效的承担,只有直接的压力,而没有弯曲变形.(5)根据荷载的类型和荷载值的大小,可以相应的改变构件的尺寸,从而制作出适应荷载的结构构件.104
缆式结构和索膜结构历史很悠久.早期,可以看到人们到处把缆式构件和薄膜构应用于建筑和工程系统.例如,用于地面支撑包括临时的庇护所和仓库,帐篷,悬挂屋顶和悬吊系统.在海洋的应用包括船只和浮标,管道航线和网状结构,海上漂浮的医院和其他的辅助支撑设备,浮控或水平面下的防波堤或储藏槽,和紧张腿和链腿等等.混合的紧张结构可以用在恶劣的环境条件下,直立的结构中被用作庇护所,举例来说,在寒冷的区域中或在大海表面之下.庇护所可以当作永久性的苫盖物设备,并且随后刚度会增加.膨胀的壳体,是将乙烯基涂上一层的织物或镀上一层薄的金属墨,可以在空气水管和倒气管中使用,并且可以浸在水中,有很好的密封性.如果双层墙被应用,墙体中充满压强的空气(或水),可以将墙壁里的空气或者水抽出来,并且注入纤维砂浆,使其饱满.最近,人们又有了新的想法,并且是可行的,应用于薄膜盖屋顶小的基础,索膜是用内部的环流气体来支撑.2.受力结构的特征由于他们有相对比较小的刚度,受拉结构对由集中荷载和动力荷载引起的比较大的位移和移动比较脆弱,他们由于预应力和使用荷载的反应是非线性的,而不会考虑到材料的直接性或者荷载的特性,预应力对结构起着一个主要的作用,对于静止平衡式(边缘荷载,自重或者压力),他们使的结构平衡,并且提供足够的强度来阻止挠度变形的进一步发生,由于平衡结构的影响,受拉构件中的预应力经常是非线性的,应力状态也是如此,都取决于力的形式和类型.使用荷载是可变的活荷载,恒荷载或者是动力荷载,在结构的使用期间内是可预见的,他们承担着使用荷载,对使用荷载或许是非线性的或者是线性的,这些都取决于使用荷载相对于应力的大小和方向,和外型的因素,反映不是严格意义上的线性关系,因此,对于不同条件下的使用荷载,他不是严格意义上的无用的,如果这样认为,并且付诸于实践,一定得仔细的考虑和完成.104
在受拉构件中,只考虑线性材料(可能顺时针线性的)已经足够,尽管如此,这有许多的例子,在这种情况下,非线性材料特点应该进一步考虑,在极限荷载作用下,复合缆和锁膜的结构应该考虑超塑性和流体塑性,以及在极限荷载作用下,温度应变与塑性特点的关系,另一个非线性关系的来源是受拉构件内部自身的反映,在超静力或者超动力荷载的作用下,不仅非线性拉应力的数值取决于缆式结构的方向和锁膜结构的表面形式,而且非保守的压应力荷载也是取决于他,在承受荷载期间,应该考虑足够的变形和扭转.3.状态阶段在这个阶段中,根据物体的确定相似性和非相似性,受拉结构的机制原理应该考虑进去,在一般的结构系统里边考虑,这种严格的受拉状况的存在和潜在的比较大的位移和偏移在分析和设计中给予足够的讨论紧在应用期间,根据受拉构件的物理性能,可划分为三个主要的阶段.第一个阶段是部署,在这种状态下缆和锁膜是打开的,从他以前密实的状态进入了预应力变形状态;第二个阶段是预应力,在恒荷载,压力和确定的永久荷载的作用下,缆或者锁膜系统变形是一个主要的平衡状态.最后,在使用荷载作用下,整个系统在全预应力系统经受着可变横荷载和动力荷载的作用在他的使用期间内.4.建筑材料4.1缆缆是由钢制成的(高强度,各向同性纤维),玻璃纤维和合成纤维等组成.结构股和钢铰线被人们普遍应用.一般股是由若干根钢丝组成,他们的排布是对称的,一根钢铰绳是由若干钢铰线围绕核心组成的.高强度是此类股的主要特征,他们还有一些重要的特性:(1)小截面(2)自重轻104
(3)很好的疲劳强度(4)抗腐蚀和锈蚀(5)很好的灵活性(6)很好的延性和抗弯性能这些特性受着钢铰线生产商的规定和限制.缆式构件主要是承受轴向力,尽管如此,由于是直铰线产生垂直钢铰在受轴向荷载作用时,被看作为”非风荷载”,的或者的弯矩是很明显的,不可忽略的;产生的力矩降低了极限荷载.一个扭平衡的缆式结构被用来产生零或者很小的扭转在荷载的作用下.在除了钢铰线应力以外,在轴向力作用下它还承受着弯曲应力,而这个值又难以确定,因为单个钢丝之间的相对运动.缆式材料有线性应变-应力关系,只是它们是强度的一部分,既没有完全发挥强度.超过了塑性极限,这个比例关系就不会存在.破坏强度效率是缆式强度的比率,相对于单个钢铰线的强度,而在钢股和钢条层中强度会更大.随着铰的数量的增加,破坏强度效率会随着降低.一根钢股是由强度较低的钢丝组成,它不能承担超拉应力,因为钢丝之间不平等的分配和不连续性,它只有低效率的破坏强度,比起可获得的脆性钢丝.4.2索膜许多不同的材料可以被用于受拉结构的构件当中,例如,超塑性材料(类似于橡胶状),构造材料和混合材料等等.超塑性材料超塑性材料在自然界是高度非线性,能够产生大的应变.因为他们有低刚度和低强度的特点,他们的应用也因此受到限制.构造材料104
构造材料有很好的抗拉强度和灵活性,而且轻质,又有很好的稳定性,对于小的混合物.预应力纤维索膜强度很高.一般自重通常范围是4到50盎斯/平方英寸(1.3到16.6Pa)来自于0.001到0.060在(0.03到1.52毫米).织物结构的强度是以长条被抗拉强度为依据的,受拉可以伸长,舌型裂口,梯形裂口和较强的黏结力.在结构当中,织物状结构的特点被很好的做了分析和阐述.条状物的抗拉强度:20到1000lb/in(35到1750N/cm)条状物的抗拉强度:比普通的条状物的抗拉强度能提高30%抗剪切强度:1到200lb/in(2到350N/cm)附着黏结力:2到40lb/in (0.1到2N/mm) 条形抗拉强度对于抗拉失败是一种很好的防御措施,剪切强度力量是织物结构的抗拒磨损和剪切的一个衡量标准.黏结力对于结构的抗拉性能和抵抗外力有很好的提高作用.合成物纤维纤维预应力加强的薄膜有比较高的强度.表面图有涂层材料的结构比起没有涂层的材料有很好的抗拉强度,因为填充材料的黏结勒对结构很好贡献,发挥着很好的保护作用,所以被涂上一层的织物有比较高的抗拉强度胜於积层塑料板.这种设计方法相对而言有很强的抗剪和抗撕强度.各种涂层材料的特点(1)尼龙.低成本,好的机理构成,而且有抵御外界条件的特点;但缺少塑性材料就会导致破坏;可以很方便的制作,但是以低使用年限为代价的;在寒冷条件下刚度增加,还可以被热封缝.(2)塑胶.104
对酸,氧,臭氧,热,阳光都有很好的抵御性能;好的机理特点;优秀的防腐蚀性能;吸水性差,优良的吸热性能,低成本;但低温时强度降低,需在节点处需要混凝土抹面或者用密封材料密封.(3)玻璃.在抵御外界性能上与塑胶相类似;有很好的抗撕裂和黏结性能;低成本,在节点初也需要混凝土抹面或者用密封材料密封.(4)聚丙烯.很好的机理性能;优秀的几乎抵抗所有的自然侵害;是高温透明的;高成本.(5)聚亚安酯.优良的机械财产和上好的磨灭抵抗性能;优良的附着基础能力;合理的抵抗外界侵害的能力;但对酸和火焰有较低的抵抗能力;透明的;可能是热密封的;花费中等.(6)在屋顶中玻璃纤维应用广泛,有很好的持久性能,是一种高强度材料.是半透明的,防火性能好,火焰-反抗的,抗撕裂和防水.表面用材料图层,因此该图层材料有自我清洁功能,预计使用年限可达20年.要添加附加剂,附加剂能改善它的灵活性,防腐性和抗太阳辐射性.104
附录2CharacteristicsoftensionstructuresTensionstructuresareonesinwhichthemainload-carryingmemberstransitappliedloadstothesupportingstructuresbydirectstresswithoutflexureorcompression.theircross-sectionaldimensionsandmethodoffabricationaresuchthattheirshearandflexuralrigidities,aswellastheirbucklingresistance,arenegligible.Therearetwobroadclassesoftensionstructures:cablestructures,comprisedofuniaxiallystressedmembers,andmembranestructures,comprisedofbiaxiallystressedmembers.Thegeneralclassofcablestructurescanbedividedintofoursubclasses:(1)Singlecablesinwhichsinglecablesegments,orseveralsimplyconnectedsimplyconnectedsegment,aresubjectedtoloadspredominantlyinasingleplaneofaction,e.g.,suspensioncables,tetherormooringlines,guylinesfortowersortents.(2)Cabletrussesinwhichprestressedsegmentsaremultiplyconnectedinasingleplaneandloadedinthatsameplane,e.g.,cable-stayedbridges,double-layercable-supportedroofs.(3)Cablenetsinwhichprestressedsegmentsaremultiplyconnectedinacurvedsurface(synclasticoranticlastic)andloadedpredominantlynormaltothatsurface,e.g.,hangingroofs,suspendednets.(4)Cablenetworksinwhichcablesegmentsaremultiplyconnectedtoformathree-dimensionalframework,e.g.,suspensionnetworks,trawlnets,multiple-legsystems.Therearefoursubclassesofmembranestructures:(1)air-supportedstructuresinwhichanenclosingmembraneissupportedbyasmall104
differentialair(orfluid)pressure,e.g.,stadiaroofs,inflatedtemporarysheltersorstorehouses.(1)Inflatedstructuresinwhichhighlypressurizedtubesordual-walledmatsareusedasstructuralmembersinaspacestructure,e.g.,inflatedbeams,columns,orarches;dual-walledshells;aircushionroofs.(2)Prestressedmembranesinwhichfabricorrubberlikesheetsarestretchedoverrigidframeworksandcolumnstoformenclosuresordiaphragms,e.g.,tents,mastedroof.(3)Hybridsystemsinwhichmembranepanelsspanbetweenprimaryload-carryingmemberssuchasprestressedcablesandrigidmembers,e.g.,reinforcedfabricroofs,fluidstoragetanks.Becauseoftheinherentlynonlinearnatureoftensionstructures,conventionallinearanalysis,whichassumessmallelasticdeformationsanddisplacements,isoftennotapplicabletocableandmembranestructures.overthepasttwodecadestherehasbeenconsiderabledevelopmentofanalysistechniquesandcomputercodesfortensionstructures.Simplifiedproceduresforpreliminarydesignsareevolving.Relativelyinexpensivetechniqursandcomputercodesmustbeselectedforthepreliminarysizingandevaluationofcandidatedesignconcepts.Afteraninitialdesignhasbeenselectedanddetailed,refinedanalysisproceduresmustbeusedtoevaluatethenonlineardynamicresponseofthestructuretobothexpectedandextremeloadconditions.1.ApplicationsoftensionstructuresTensionstructuresarewellsuitedtosupportbroadlydistributeddeadloadsliveloadssuchaswind,oceancurrents,anddriftforcesduetowaves.Itshouldnotbesurprisingthatlightweighttensionstructuresresemblebiological104
forms,sincesuchformsalsosupportloadsbytensioninpneumaticallyprestressedskinsandfibers.Someoftheadvantagesoftensionmembersforuseasstructuralcomponentsare:(1)theyarelightweightandcollapsibleandthereforeeasytotransportanderect.(2)Theycanbeprefabricatedinafactory,havelowinstallationcosts,andarepotentiallyrelocatable.(3)Forair-supportedstructures,theprimaryload-carryingmechanismisthehabitableenvironmentitself,i.e,apressurizedmixtureofgases.(4)Theenvironmentalloadsareefficientlycarriedbydirectstresswithoutbending.(5)Theyareload-adaptiveinthatthememberschangegeometrytobetteraccommodatechangesinloadpatternsandmagnitudes.Thehistoryofearlyapplicationsofcableandmembranestructuresapplicationsincludetemporarysheltersandwarehouse,tents,hangingroofs,andsuspensionsystems.Seabasedapplicationsincludemooredvesselsandbuoys,trawllinesandnets,towedarray,floatinghospitalsandotherlogisticalsupportfacilities,floatingorsubmergedbreakwatersorstoragetanks,andtension-legorcatenary-legplatforms.Hybridtensionstructurescouldbeusedasinitialsheltersintheerectionofstructuresinhostileenvironments,e.g.,incoldregionsorundertheoceansurface.Theshelterscouldlaterbestiffenedfromtheinsidetoformmorepermanentfacilities.Aninflatableshell,possiblymadeofvinyl-coatedfabricorthinmetallicfilm,couldbesubmergedinpackagedformwithallairhosesandairlocksattached.104
Thenwithminimalsubsurfacelabor,itcouldbepressurizedtothedesiredshape.Dependingonthematerialusedintheconstructionoftheshellandonthedepthofitsintendeduse,theinflateddomewouldprovideeitherasemipermanentenvironmentortemporaryfalseworkandshelterwithinwhichconcretecouldbesprayedtoconstructapermanentatmosphericenvironment.ifadual-walledformwereused,thepressurizedair(orwater)withinthewallscouldbedisplacedbyfiber-reinforcedconcretepumpedfromthesurface.Recentthoughthasbeengiventothefeasibilityofusingpressurizedmembranestoroofsmallbasesortowns,themembranebeingsupportedprimarilybythecirculatinginteriorair.2.behavioroftensionstrcturesBecauseoftheirreducedstiffnesscharacteristics,tensionstructuresaresusceptibletolargemotionsduetoconcentratedloadsanddynamiceffects.Theyrespondinanonlinearfashiontobothprestressingforcesandin-cerviceforces,regardlessoflinearityofmaterialorloads.Prestressingforcesarethoseforces(edgeloads,self-weight,orpressure)whichactonapredominantconfigurationofstaticepuilibriumforthestructure.theystabilizethestructureandprovidestiffnessagainstfurtherdeflection.Theresponseofatensionstructuretoprestressingforcesisalwaysnonlinearinthatequilibriumconfigurations,aswellasthestateofstress,aredependentonthoseforces.In-serviceforcesarethosevariableliveloads,staticordynamic,whichthestructuremaybeexpectedtoencounterduringitsservicelife.Theyaresuperposedupontheprestressingforces,theresponsetoin-serviceforcesmaybenonlinearorquasi-linear,dependingonthedirectionsandmagnitudesofthein-serviceforcesrelativetothestateofstressin,andconfigurationof,the104
prestressedstructure.Theresponseisnotstrictlylinearandthereforesuperpositionofresultsfordifferentin-serviceloadingconditionsisnotstrictlyvalidand,ifnotdone,mustbedonecarefully.Itisusuallysufficienttoconsideronlylinear(possiblypiecewiselinear)materialbehaviorfortensionstructures.Thereareinstances,however,wherenonlinearmaterialcharacteristicsshouldbeconsidered:hyperelasticandviscoelasticbehaviorofpolymercablesandmembranes;nonisotropicwovenfabrics;andthermal-elasticandelastoplasticbehaviorunderextremeloads.Anotherpotentialsourceofnonlinearitiesofresponseistheinteractionoftensionstructureswithhydrostaticandhydrodynamicloads.Notonlyarethemagnitudesofdragforcenonlinear,buttheyarealsononconservativeinthatdirectionsofpressureloadsaredependentonorientationsofthecableaxesandmembranesurfaces,whichmayundergoconsiderablerotationduringloading.3.phasesofbehaviorinthissectionthemechanicsoftensionstructuresareconsideredwiththeobjectiveofidentifyingsimilaritiesanddissimilaritiesoftheirresponsetothatofconventionalstructuralsystems.Theimplicationsofstrictlytensilebehaviorandofpotentiallylargedisplacemenrsonanalysisanddesigntechniquesarediscussed.Thephysicalbehaviorofatensionstructureduringtheapplicationofloadscanbedividedintothreeprimaryphases.Thefirstphaseisdeployment,inwhichthecableormembranesystemunfoldsfromitscompactconfigurationintoastateofincipientstraining.Thesecondphaseisprestressing,inwhichthecableormembranesystemdeformsintoapredominantequilibriumconfigurationundertheactionofdeadweight,pressure,orotherfixedlifetimeloads.Thefinal,orin-serice,phaseisthestageinwhichthefullyprestressedsystemissubjectedto104
variableliveordynamicloadsduringitsservicelife.4.Materialsofconstruction4.1CablesCableshavebeenmadeofsteel,Kevlar(registeredDuponttrandemark;asyntheticarmedfiber),fiberglass,andpolyester.Structuralstrandsandstructuralropesarecommonlyutilizedascables.Astrandconsistsofsteelwireswoundhelicallyaroundacenterwireinsymmetricallayers.Aropeconsistsofseveralstrandswoundhelicallyaroundacore.ahigh-tensilebreakingstrengthisaprimarypropertyofthewirerope.Thereareotherimportantproperties:(1)smallcrosssection(2)lowweight(3)longfatiguelife(4)resistancetocorrosionandabrasion(5)highflexibility(6)goodstretchandrotationalbehaviorthesepropertiesdependontheropemanufactureandwirecontrol.Cablesactprincipallyasaxialelements;however,becauseofthehelicalwires,atorquemaybeinducedasthehelicalwirestryto“unwind”duringaxialloading.Theeffectsofinducedorexternallyappliedtorquemaybesignificant;inducedtorquedecreasestheultimatestrength.Atorque-balancedcableisonedesignedtoyieldzeroorverysmallamountsofrotationunderload.Inadditiontothestressesinthewiresduetotheaxialforce,thewouldwiresaresubjectedtobendingstresseswhicharedifficultduototheaxialforce,thewoundwiresaresubjectedtobendingstresseswhicharedifficulttoevaluatebecauseofrelativemovementoftheindividualstrands.104
Cablematerialstypicallyhavelinearstress-strainrelationshipsoveronlyaportionoftheirusablestrength.Beyondtheelasticlimit,theproportionalrelationshipsoveronlyaportiontheirusablestrength.beyondtheelasticlimit,theproportionalrelationshipsdonothold.Breaking-strengthefficiencyistheratioofcablestrengthtothesumoftheindividualwirestrengthsandisgraterforropesandstrandlay.Thebreaking-strengthefficiencyisreducedasthenumberofwiresinthestrandisincreased.aropemadeupofbrittlewireswillbelessabletobearoverstressingduetounequaldistributionofstrainsandconsequentlywilldevelopalowerbreakingstrengthefficiencythancouldbeobtainedwithmoreductilewire.4.2membranesVariousmaterialscanbeusedinthefabricationofatensionstructure,suchashyperelastic(rubberlike)materials,fabrics,composites,etc.HyperelasticmaterialsHyperelasticmaterialsarehighlynonlinearinnatureandcansustainlargestrains.Becauseoftheirlowstiffnessandstrengthpropertiestheyhavelimitedapplications.Fabricsfabricshouldhavehightensilestrengthandshouldbeflexibleandlightinweight.Itshouldhavegooddimensionalstability,behighlyresistanttothepropagationofminoraccidentaldamage,andbeeasilyandcheaplyseanedorjointedinareliablemanner.Finally,thefabricshouldberesistanttoenvironmentaldegradationandshouldbefire-resistant.Todatefabrichasrelativelylowresistancetocyclicfoldingandwrinking.Fabricisspecifiedashavingaparticularwidthandweightpersquareyard.Thicknessmaybederivedfromthedensityofthematerial.Commonweightsrange4to50oz/yd(1.3to16.6Pa)withderivedthicknessesof0.001to104
0.060in(0.03to1.52mm).Strengthsoffabricsaredescribedintermsofstriptensilegrabtensile,tonguetear,trapezoidaltear,andadhesion.Becausemostfabricsareorthotropic,propertiesaretypicallyspecifiedforeachweavedirectioninfabrics.Striptensile:20to1000lb/in(35to1750N/cm)Grabtensile:typically30percenthigherthanstriptensileTearstrength:1to200lb/in(2to350N/cm)Adhesionstrength:2to40lb/inStriptensilestrengthisamrasureofthefabricresistancetotensilefailure.tearstrengthisanindicatorofthefabric’sresistancetoabrasionandtears.Adhesionstrengthrelatestotheresistanceofthefabrictodelamination.CompositesFiber-reinforcedmembraneshavehigherstrengths.Thecoatedfabricshavehighertensilestrengthsthanthelaminatesbecausefabricwithacloserweavemaybeused.Coatedfabricsalsohavebetteradhesion.Laminateshavescrimswithanopenweavetopermitthe“strike-through”necessaryforgoodfilmadhesion.thismethodofconstuctiondoseresultinrelativelyhighertearstrengthsastheindividualfibersarefreertobuncgtoresisttearing.Somepropertiesofcommonlyusedfabricsare:(1)nylon.Strongwithgoodelasticrecovery;affectedbymoisturetoagreaterextentthanispolyester;affectedbysunlightandoxidation;flammable.(2)Poiyester.Notquiteasstrongasnylon,andalittlemoreexpensive;unaffectedbymoistureandresistanttoenvironmentaldegradation;highermodulusofelasticitythannylon,andhasaslightlybetterdimensionalstability;flammable.(3)Glass.Strongwithcompletedimensionalstability,andexceptionalresistancetoallformsofenvironmentaldegradation;poorabrasionresistance;translucent;flame-resistant;nosewnseams.104
(4)Polypropylene.Strong;outstandingresistancetochemicaldegradation;adhesiveproblemsreported;coatingmaterialsmustbecuredatlowtemperature.Itisnotpossibleatpresenttosatisfysimultaneouslyallrequirementsinasinglematerial.Thebestsolutionisacoatedfabricinwhicheachofthecomponentsisselectedtofulfillaparticularsetofconditions,andthefinalmaterialsismuchbetterthanthesumofthecomponents.(1)vinyl.Lowcostwithgoodmechanicalandweatheringproperties;deteriorationiscausedbylossofplasticizer;canbemadetransparentatthecostofreducedservicelife;stiffensincoldenvironments;canbeheatsealed.(2)Hypalon.Excellentresistancetoacid,oxidation,ozone,heat,andsunlight;goodmechanicalproperties;excellentabrasionresistance;lowwaterabsorption;goodcolorretention;lowcost;poorlow-temperatureresistance;requirescementedorseamjoints.(3)Neoprene.VerysimilartoHypaloninresistanceandweatherability;bettertearresistanceandadhesiontobasefabric;lowcost;requirescementedorseamjoints.(4)Fluoreolastomer.Goodtoexcellentmechanicalproperties;outstandingresistancetoalltypesofdeterioration,particularlyathightemperatures;transparent;highcost.(5)Polyurethane.Excellentmechanicalpropertiesandsuperiorabrasionresistance;excellentadhesiontobasefabric;reasonableweatherresistance;onlyfairacidandflameresistance;transparent;canbeheatsealed;mediumcost.Teflon-coatedfiberglasshasbeenusedinfabricroofsandisadurable,high-strengthmaterial.thefabricistranslucent,flame-resistant,tearproof,andwaterproof.ThefabriciscoatedwithTeflonfluorocarbonresin,andthereforethecoatedmaterialisself-cleaninganda20-yearlifeexpectancyisanticipated.TheTeflondispersioncontainsadditivesthatimproveflexibility,abrasionresistance,104
andsolartransmission.104'
您可能关注的文档
- 8-10层钢筋混凝泥土框架结构毕业设计论文计算书
- 七层框架结构毕业设计
- 十层框架结构毕业设计计算书
- 同济大学土木工程框架结构毕业设计课程设计
- 四层钢筋混凝土框架结构毕业设计
- 多层框架结构毕业设计
- 多层框架结构毕业设计计算书
- 框架结构毕业设计计算书完整版
- 毕业设计论文—高层办公楼框架结构毕业设计计算书-精品
- 钢框架结构毕业设计计算书
- 钢筋混凝土框架结构毕业设计--参考
- 高层办公楼 框架结构毕业设计计算书
- 土木工程(建筑工程)专业框架结构毕业设计
- 完整框架结构毕业设计计算书
- 框架结构毕业设计汇总 - 结构理论
- 五层现浇框架结构毕业设计计算书
- 土木工程建筑工程专业框架结构毕业设计
- 框架结构毕业设计_--142606301