脚手架设计计算书.doc

设计计算书5.1落地式脚手架承载计算计算依据：（1）钢管截面特征：（钢号Q235，b类） 表7-12规格(mm)483.5惯性矩I(mm4)12.19104单位重量qo(kg/m)3.84抵抗矩W(mm3)5.08103截面积A(mm2)489回转半径i(mm)15.8抗弯、抗压容许应力N/mm2205（2）脚手架特性参数： 表7-13立杆纵距La(m)1.55脚手板重量q1(/)0.25立杆横距Lb(m)1.1连墙件纵距Lw(m)3.6大横杆步距h(m)1.8连墙件横距hw(m)3.40施工荷载q(kN/)3同时作业层数n12内立杆距结构外皮宽度b1(m)0.35作业面铺脚手板宽度b2(m)1.1+0.6=1.7（3）相关计算参数： 表7-14项目数值来源扣件钢管架构件自重计算基数gk1值（kN/m）0.1081建筑施工手册（第四版）表5-7作业层面材料自重计算基数gk2值（kN/m）0.3891建筑施工手册（第四版）表5-10整体拉结和防护材料自重计算基数gk3(kN/)0.0768建筑施工手册（第四版）表5-11作业层施工荷载计算基数qk值（kN/m）1.65建筑施工手册（第四版）表5-12风压高度变化系数z架高17.7m处1.23建筑结构荷载规范（GB50009-2001）架高35.7m处1.79脚手架风荷载体型系数s1.3建筑施工手册（第四版）表5-6辽宁地区基本风压wo(kN/)0.55建筑结构荷载规范（GB50009-2001）扣件式钢管脚手架立杆计算长度系数1.51建筑施工手册（第四版）表5-16材料强度附加分项系数（接受弯构件考虑）rm1.1705建筑施工手册（第四版）表5-5轴心受压构件稳定系数0.24建筑施工手册（第四版）表5-18注：计算长度l0=h=1.511.8=2781mm；长细比=l0/I=2718/15.8=172附表：施工手册（第四版）表5-7、表5-10、表5-11、表5-12、表5-6、表5-16、表5-5、表5-18：扣件式钢管手架degk1值 表5-7步距h(m)立杆横距Lb(m)立杆类别gkl(kN/m)，当La(m)为0.60.91.21.51.82.10.90.6中0.12270.13650.15030.16400.17780.1916边0.12270.13650.15020.16400.17780.1915角0.12030.12650.13280.13910.14530.15160.9中0.13530.14910.16280.17660.19040.2041边0.12900.14270.15650.17030.18400.1978角0.12650.13280.13910.14530.15160.15791.2中0.14790.16160.17540.18920.20290.2167边0.13520.14900.16280.17650.19030.2041角0.13280.13910.14530.15160.15790.16411.20.9中0.11180.12210.13250.14280.15310.1634边0.10710.11740.12770.13800.14840.1587角0.10520.10990.11460.11930.12400.12871.2中0.12120.13160.14190.15520.16250.1729边0.11180.12210.13240.14270.15310.1634角0.10990.11460.11930.12400.12870.13341.5中0.13070.14100.15130.16160.17200.1823边0.11650.12680.13710.14740.15780.1681角0.11460.11930.12400.12870.13340.13811.50.9中0.09770.10600.11420.12250.13070.1390边0.09390.10220.11040.11870.12700.1353角0.09240.9620.10000.10370.10750.11131.2中0.10520.11350.12180.13000.13830.1465边0.09770.10590.11420.12250.13070.1390角0.9620.10000.10370.10750.11130.11501.5中0.11280.12100.12930.13760.14580.1541边0.10140.10970.11800.12620.13450.1427角0.10000.10370.10750.11130.11500.11881.8中0.12030.12860.13680.14510.15340.1616边0.10520.11350.12170.13000.13820.1465角0.10370.10750.11130.11500.11880.12251.80.9中0.08830.09520.10210.10900.11580.1227边0.08510.09200.09890.10580.11270.1196角0.08390.08700.09020.09330.09640.09961.2中0.09460.10150.10840.11520.12210.1290边0.00830.09510.01020.10890.11580.1227角0.08700.09020.09330.09640.09960.10271.5中0.10090.10780.11460.12150.12840.1353边0.09140.09830.10520.11210.11890.1258角0.09020.09330.09640.09960.10270.10581.8中0.10720.11400.12090.12780.13460.1415边0.09450.10140.10830.11520.12210.1290角0.09330.09640.09960.10270.10580.10902.10.9中0.08160.08750.09340.09930.10520.1111边0.07890.08480.09070.09660.10250.1084角0.07780.08050.08320.08590.08860.09131.2中0.08700.09290.09880.10470.11060.1165边0.08160.08740.09330.09920.10510.1110角0.08050.08320.08590.08860.09130.09391.5中0.09240.09830.10420.11010.11600.1219边0.08420.09010.09600.10190.10780.1137角0.08320.08590.08860.09130.09390.09661.8中0.09770.10360.10950.11540.12130.1272边0.08690.09280.09870.10460.11050.1164角0.08590.08860.09130.09390.09660.0933 作业层面材料自重计算基数gk2值 表5-10序次脚手架类别脚手板种类板底支承间距(m)拦护设置gk2(kN/m)，当立杆横距Lb(m)为0.91.21.51.81扣件式钢管脚手架竹串片0.75有无0.35870.20870.41120.26120.46370.31370.15620.366223木、其他1.0有无0.34590.19590.34840.29840.45090.30090.50340.35344冲压钢1.5有无0.33310.18310.38560.23560.43810.28810.49060.34065碗扣式钢管脚手架无间横杆挂扣式La有无0.26250.11250.30000.15000.33750.18750.37500.22506其他有无0.30750.15750.36000.21000.41250.26250.46500.31507设间横杆竹串片0.75有无0.36080.21080.41330.26330.46580.31580.41830.368389木、其他1.0有无0.34750.19750.40000.25000.45250.30250.50500.355010冲压钢1.5有无0.31170.16170.35670.20670.40170.25170.44670.296711门式钢管脚手架挂扣式1.8木挡板钢网无0.20250.13250.11250.27000.17670.1500 整体拉结和防护材料自重计算基数 gk3 值表5-11序次脚手架类别整体拉结杆件设置情况围护材料封闭类型gk3(KPa/)，当La(m)为1.21.51.82.11扣件式钢管脚手架剪刀撑，增加一道横杆固定封闭材料安全网，塑料纺织布半全0.06020.06140.07530.07680.09040.09220.10540.10752席子半全0.06380.06860.07980.08580.09580.10300.11170.12013竹笆半全0.08900.11900.11130.19880.13360.17860.15580.20834碗扣式钢管脚手架不设斜杆，增加一道横杆固定封闭材料安全网，塑料纺织布半全0.02810.02930.03510.03660.04210.04390.04910.5125席子半全0.01370.03650.03960.04560.04750.05470.05540.06386竹笆半全0.05690.08690.07110.10860.08530.13030.09950.152071/3框格设斜杆，增加一道模杆固定封闭横杆固定封闭材料安全网，塑料纺织布半全0.04230.04370.05310.05460.06370.06550.07430.07648席子半全0.04610.05090.05760.06360.06910.07630.08060.08909竹笆半全0.07130.10130.08910.12660.10960.15190.12470.177210门式钢管脚手架交叉支撑，6步一道水平加强杆安全网，塑料纺织布半全0.03420.036011席子半全0.03960.046812保护网板半全0.12240.212413竹笆半全0.07740.1224 作业层施工荷载计算基数qk 值 表5-12序次实用施工荷载标准值（kN/）qk(kN/m)，当立杆横距Lb(m)为0.91.21.51.8131.351.82.252.7220.91.21.51.8310.450.60.750.94q00.45q00.6 q00.75 q00.9 q0 脚手架风荷载体型系数s 表5-6背靠建筑物de状况全封闭敞开、开洞脚手架状况各种封闭情况1.01.3敞开stw 扣件式钢管脚手架立杆de计算长度系数 表5-16立杆横距Lb(m)连墙件布置2步3跨3步3跨双排架1.051.501.701.301.551.751.551.601.80单排架1.51.802.00 Q235钢轴中心受压构件de稳定系数 表5-18012345678901.0000.9970.9950.9920.9890.9870.9840.9810.9790.976100.9740.9710.9680.9660.9630.9600.9580.9550.9520.949200.9470.9470.9440.9410.9380.9360.9300.9270.9240.921300.9180.9150.9120.9090.9060.9030.8990.8960.8930.889400.8860.8820.8790.8750.8720.8680.8640.8610.8580.855500.8520.8490.8460.8430.8390.8360.8320.8290.8250.822600.8180.8140.8100.8060.8020.7970.7930.7890.7840.779700.7750.7700.7650.7600.7550.7500.7440.7390.7330.782800.7220.7160.7100.7040.7980.6920.6860.6800.6730.557900.6610.6540.6480.6410.6340.6260.6180.6110.6030.5951000.5880.5800.5730.5660.5580.5510.5440.5370.5300.5231100.5160.5090.5020.4960.4890.4830.4760.4700.4640.4581200.4520.4460.4400.4340.4280.4230.4170.4120.4060.4011300.3960.3910.3860.3810.3760.3710.3670.3620.3570.3531400.3940.3440.3400.3360.3320.3280.3240.3200.3160.3121500.3080.3050.3010.2980.2940.2910.2870.2840.2810.2771600.2740.2710.2680.2650.2620.2590.2560.2530.2510.2481700.2450.2430.2400.2370.2350.2320.2300.2270.2250.2231800.2200.2180.2160.2140.2110.2090.2070.2050.2030.2011900.1990.1970.1950.1930.1910.1890.1880.1860.1840.1822000.1800.1790.1770.1750.1740.1720.1770.1690.1670.1662100.1640.1630.1610.1600.1590.1570.1560.1540.1530.1522200.1500.1490.1480.1460.1450.1440.1430.1410.1400.1392300.1380.1370.1360.1350.1330.1320.1310.1300.2190.2182400.1290.1260.1250.1250.1230.1220.1210.1200.1190.1182500.1175.1.1验算项目和步骤：本脚手架属施工荷载由纵向水平杆传给立杆情况，传递线路如下：脚手板小横杆大横杆立杆地基。因此应对基础、连墙件、立杆、纵横向水平杆等进行验算。（1）纵、横向水平杆承载验算：表7-15横向水平杆（以长杆为对象）纵向水平杆（以三跨为对象）计算简图荷载q=0.775(1.20.25+1.43)=3.49kN/mP=3.490.51.7=2.97kN抗弯强度Mmax=3.490.62/2=0.63kNmMmax=0.2132.971.55=0.98kNm=0.63106/5080=124N/mm2f=205N/mm2=0.98106/5080=193N/mm2f=205N/mm2挠度W=(41.10.62-1.13+30.63)1093.490.6103/(242.0610512.19104)=3.13mmL/400=1700/400=4.25mmW=1.6152.971031.553109/(1002.0610512.19104)=7.11mmL/150=1550/150=10mm（2）立杆、连墙件和扣件、顶板和基础验算表7-16立杆稳定验算主楼单立杆部分（架高17.735.7m）立杆计算截面以上架高H0=18.0m 恒载标准值NGK=H0(gk1+gk3)+n1Lagk2NGK=18.0(0.1081+0.0768)+21.550.3891=4.53kN活载标准值NQK=n1Laqk=21.551.65=5.12kN轴向力设计值N=1.2NGK+0.851.4NQK=1.2(NGK+NQK)N=1.2(4.53+5.12)=11.58kN风荷载标准值Wk=0.7zswoWk=0.71.791.30.55=0.89kN/风载产生弯矩设计值Mw=0.12WkLah2Mw=0.120.891.551.82=0.53kNm稳定验算0.9(N/A+Mw/W)f/rm0.9【11.58103/(0.24489)+0.53106/5080】=182.53N/mm2205/(0.91.1705)=194.6N/mm22连墙件稳定验算风荷载产生轴向力设计值New=1.4WkAwNew=1.40.893.63.4=1525kN脚手架平面外变形产生de轴向力N0=5kN连墙件轴向力设计值N1=New+N0N1=15.25+5=20.25kN连墙杆de计算长度l0=1.1+0.75=1.85m=1850mm长细比=l0/i=1850/15.8=117.09轴心受压构件稳定系数=0.47建筑施工手册（第四版）表5-18稳定验算N1/Af/rm20.25103/(0.472489)=44.05N/mm2205/1.5607=146N/mm2扣件抗滑验算N1Rc按直角扣件计：Rc=8.0kN/个20.25kN48.0=32kN柱距6.80m应设6个直角扣件主楼单立杆部分（架高0.00-17.70m）地基承载力验算立杆底座承载力验算NRb立杆底座承载力设计值Rb=40kN不做此项验算东西两侧回填土地基承载力验算N/Adkfk按回填土k=0.4 Ad=1.550.4=0.62 fk=10t/=98kN/不做此项验算南北两侧顶板地基承载力验算N/AdAd=1.550.4=0.62按设计提供数据=1.4活载+1.2恒载=1.45+1.26=14.2kN/不做此项验算由表知：1）杆承载最小安全系数（194.6-183.58）/194.6100%=5.68%5%；2）回填土承载最小安全系数（39.2-34.61）/39.2100%=11.71%5%。显然验算项目均是安全de。（3）顶板基础不回顶de立杆搭设限高计算；表7-17设立杆计算截面以上架高H0立杆纵距La=1.55m立杆横距Lb=1.1m大横杆步距h=1.8m施工荷载qk结构时qk=1.65kN/装修时qk=1.1kN/同时作业层数n1结构时n1=1装修时n1=2扣件钢管架构件自重计算基数gk1=0.1081kN/m作业层面材料自重计算基数gk2=0.3891kN/m整体拉结和防护材料自重计算基数gk3=0.0768kN/m恒载标准值NGK=H0(gk1+gk3)+n1Lagk2NGK=H0(0.1081+0.0768)+21.550.3891=0.1849H0+1.2062kN活载标准值NQK结构时NQK=n1Laqk=21.551.65=2.56kN取最大值3.1kN装修时NQK= n1Laqk=21.551.1=3.1kN轴向力设计值N=1.2NGK+1.4NQKN=1.2(0.1849H0+1.2062)+1.43.1=0.22188H0+5.78744kN顶板地基承载力验算N/AdAd=1.550.4=0.62按设计提供数据=1.4活载+1.2恒载=1.45+1.26=14.2kN/N=0.22188H0+5.78744Ad=0.6214.2=8.804kN 解得：H013.60m必须由项目部安全员验收合格后方可继续施工。（4）卸荷装置de稳定承载计算：卸荷吊点间距取为一个柱距(6.8m)与结构外皮间距1.2m，卸载能力按基承载力de一半分配上部荷载（架高0.0017.70m），且不超过上部荷载de1/3。其计算过程如下表所示：表7-18每个吊点承载脚手架（架高0.0017.70m）一个纵距内全部荷载设计值：N=1.217.7(0.1081+0.0768)+21.550.3891+1.421.551.65=8.86kNA点P1=0.5(N8.1/1.551/3)=0.58.866.8/1.551/3)=6.47kNB点P2=0.5(N6.8/1.551/3)+1.221.550.38910.35/1.16.8/1.55=8.48KN钢丝绳受力计算斜拉钢丝绳de计算简图如右。由图知：sina=0.8 cosa=0.6 sin=0.91 cos=0.41TOA=P1/sina=13.47/0.8=16.84kN TOB=P2/sin=27.78/0.91=30.53kNTAB=TOAcosa+TOBcos=16.840.6+30.530.41=22.62kN则：钢丝绳最大拉力Tmax=TOB=30.53kN选择钢丝绳卡环钢丝绳之间荷载不均匀系数a=0.85(对619钢丝)钢丝绳使用安全系数K1=3.5由公式TmaxaPg/K1知钢丝绳de破断拉力总和Pg满足于：PgTmaxK1/a=30.533.5/0.85=125.71kN则选用619、15.5de钢丝绳，其Pg=138.5kN125.71kN要求卡环与钢丝绳配套，查表知与15.5de钢丝绳配套de卡环为GD21号，其安全荷重Qb=205.8kN125.71kN，故它是安全de。吊环处抗滑承载按规定每个扣件抗滑承载力设计值为8.0kN，而此结构吊点处，水平方向分力最大值TAB=22.62kN，只要三个扣件就满足了。每个吊环处现有两个扣件与立杆卡紧，因此水平方向抗滑移需增设两个扣件，以保证结构安全。垂直方向分力为：F=P2=27.78kN，所需扣件数：n=F/8.0=27.78/8.0=3.47个，现吊环处有两个扣件，不能满足要求，需增设两个扣件，以保证结构安全。5.2悬挑式脚手架de稳定承载计算该悬挑架所用de钢管材质与扣件式落地架相同，其截面特征参数参见表7-12中所列数据。承受荷载de传递途径是：脚手板小横杆大横杆立杆承力架楼面顶板。需要计算de项目有：立杆de稳定性；连墙件de强度、稳定性和扣件de抗滑力；悬挑杆de强度、挠度；斜撑杆和钢丝绳de稳定性。5.2.1立杆、连墙件和扣件de稳定承载计算：表7-19恒载标准值计算内容备注钢管架构件gk1=0.1089kN/m建筑施工手册表5-7作业层面材料gk2=0.4112kN/m建筑施工手册表5-10整体拉结和防护材料gk3=0.0768kN/m建筑施工手册表5-11立杆计算截面以上架高H0=18.00mNGK=H0(gk1+gk3)+n1Lagk2=18(0.1089+0.0768)+11.50.4112=3.9594kN取同时作业层数n1=1活载作业层施工荷载qk=1.8kN/m建筑施工手册表5-12NQK（标准值）=n1Laqk=11.51.8=2.7kN轴向力设计值N=1.2NGK+0.851.4NQK=1.2(NGK+NQK)=1.2(3.9594+2.7)=7.99kN风载产生弯矩风压高度变化系数Z=1.14建筑结构荷载规范风荷载体型系数s=1.3建筑施工手册表5-6辽宁地区基本风压wo=0.55kN/建筑结构荷载规范风载标准值Wk=0.7Zswo=0.71.141.30.55=0.57kN/Mw(设计值)=0.12WkLah2=0.120.571.51.82=0.33kNm立杆稳定验算材料强度附加分项系数rm=1.1705按受弯构件考虑立杆计算长度系数=1.53建筑施工手册表5-16计算长度lo=h=1.531.8=2754mm长细比=lo/I=2754/15.8=174.3轴心受压构件稳定系数=0.235建筑施工手册表5-18稳定验算0.9(N/A+MW/W)f/ rm7.99103/(0.235489)+0.33106/5080=134.49N/mm2205/(0.91.1705)=194.6N/mm2 安全连墙件稳定验算风载产生轴力设计值New=1.4WkAw=1.40.573.66.8=19.53kN脚手架平面外变形产生de轴向力N0=5kN连墙件轴向力设计值N1=New+N0=19.53+5=24.53kN连墙杆de计算长度lo=1.2+0.35=1.55m=1550mm长细比=lo/i=1550/15.8=98.1轴心受压构件稳定系数=0.603建筑施工手册表5-18稳定验算N1/Af/ rm24.53103/(0.6032489)=41.59N/mm2205/1.5607=146N/mm2扣件抗滑验算N1Rc按直角扣件计：Rc=8.0kN/个24.53kN48.0=32kN 安全5.2.2水平挑杆、斜撑杆和钢丝绳de稳定承载计算：表7-20第一层悬挑杆稳定承载验算第三层悬挑稳定承载验算外立杆F1=0.51.25.03/2(0.1089+0.0768)+11.50.4112+1.411.51.8=2.54kNF1=0.51.2(4.2+4.2/2)(0.1089+0.0768)+11.50.4112+1.411.51.8=2.96kN内立杆F2=F1+0.351.5(1.20.4112+1.41.8)/1.2=3.48kNF2=F1+0.351.5(1.20.4112+1.41.8)/1.2=3.9kN挑杆及其组件稳定承载验算绳子张力T=(1.55F1+0.35F2)/(1.55sin59)=3.88kN斜撑杆压力P=(1.55F1+0.35F2)/(1.55sin70)=4.09kN最大剪力QB=F1+F2-Tsin59=2.69kN最大剪力QB=F1+F2-Psin70=3.02kN最大弯矩MB=1.2Tsin59-1.2F1=0.94kNm最大弯矩MB=1.2Psin59-1.2F1=1.06kNm挑杆轴力N=Tcos59=2.0kN挑杆轴力N=Pcos70=1.4kN由前面卸荷计算知：张力T满足承载要求，在此不做验算。对斜撑杆：=N/A=4.09103/489=8.36N/mm2=205N/mm2 安全抗剪验算：max=2QB/A=23.02103/489=12.35N/mm2=205N/mm2 安全长细比=l0/i=1550/15.8=98.1轴心受压构件稳定系数=0.603抗弯压验算：0.9(N/A+Mw/W)f/mm22.0103/(0.603489)+0.94106/5080=19