脚手架计算(表格中含公式)

4m1200mm0mm1200mm1200mm2步截面模量W5080mm3回转半径i15.8mm截面积A489mm2截面惯性距I121900mm4钢材的弹性模量E206000N/mm222.4N/m38.4N/m60.8N/m施工均布活荷载P=2000N/m2600N/m131.47N·mσ=M/W=25.88N/mm2≤[f]=205N/mm2其中:0.51mm≤[w]其中:8mmN立杆纵距la步高h立杆横距lb外伸长度a附件1：普通钢管脚手架计算KF002一、计算参数搭设高度H适用范围：普通钢管三排落地式脚手架步数n脚手架的钢管选用(φ48×3.5)其计算参数为：本计算书中的规范指的是《建筑施工扣件式钢管脚手架安全技术规范》JGJ130—2001二、脚手架计算（一）、大横杆的计算把大横杆简化为连续三跨梁来计算简图如下1、荷载计算恒荷载计算竹排片的规格为1.2m×1.5m，自重标准值为56N/m2竹排片自重56×lb÷3=钢管自重小计：g=活荷载计算结构脚手架q=P×lb÷4=2、强度验算荷载作用下的弯矩M的计算M=0.1×（g×1.2+q×1.4）×la2=大横杆强度的验算满足要求[f]为Q235钢抗拉、抗压和抗弯强度设计值见规范表5.1.63、挠度验算w=0.677×（g×1.2+q×1.4）×la4/（100×E×I）=[w]为受弯构件允许挠度值查规范表5.1.8[w]=la/150=满足要求荷载作用下的中间支座反力的计算R=1.1×（g×1.2+q×1.4）×la=1205.11RRqR1R1laalal1300mmM=R×c=361.5N·mσ=M/W=71.2N/mm2≤[f]=205N/mm22.38mm≤[w]其中:8mm602.554NR1+R=N≤其中:184.32N46.08N90N80.64N168N28.8N597.84NN20.921.040.4kN/m20.27kN/m2153.6N（二）、小横杆的计算小横杆只考虑大横杆产生的集中力作用，计算简图如下：1、强度验算计算集中力R作用下的弯距M集中力R到支座的距离c=lb/4=小横杆的验算满足要求2、挠度验算w=R×c×（3lb2-4c2）/（24×E×I）=[w]=lb/150=满足要求验算小横杆和立杆间扣件的抗滑承载力根据实际的受力情况可知R1=0.5×R=则小横杆和立杆间的扣件受力是1807.66满足要求Rc为扣件抗滑承载力设计值见规范表5.1.7Rc=8000N（三）立杆计算1、荷载计算恒荷载计算大横杆自重38.4×la×4=小横杆自重38.4×（lb+a）×1=扣件自重15×6=竹筏片脚手板56×la×lb=栏杆及挡板自重140×la=安全网自重20×la×h=小计：N1=活荷载计算N2=P×la×lb=2880活荷载的层数n'风荷载的计算计算参数：风压高度变化系数uz脚手架风荷载体型系数us基本风压wowk=0.7×uz×us×wo=立杆自重N3=38.4×H=2、立杆内力的计算立杆采用单立杆RRcccR1R1lb22.15m其中：1.155单杆计算长度系数u查规范表5.3.31.55136≤[λ]=2100.1744328.9N55.09N·m61.72N/mm2≤4933.73NN/mm2≤[f]=205N/mm2n''=0246N2.43m其中：1.155单杆计算长度系数u查规范表5.3.31.75154≤[λ]=2100.1744439.5N55.09N·m31.51N/mm2≤5044.32NN/mm2≤[f]=205N/mm2N=(n×N1/2+N3)×1.2+(n'×N2/2)×1.4=单杆计算长度系数u查规范表5.3.3立杆稳定性验算N/（φ×A×2）=29.64满足要求满足要求2.2不组合风荷载的作用立杆底端的轴力为立杆稳定性验算N/（φ×A×2）+M/(W×2)=[f]=205N/mm2N=(n×N1/2+N3)×1.2+0.85×(n'×N2/2)×1.4=风荷载作用下的立杆段弯距值M=0.85×1.4×wk×la×h2/10=2.1组合风荷载的作用立杆底端的轴力N为立杆从第n''步开始往下采用双立杆有关参数的计算计算长度lo=k×u×h=计算长度附加系数k单杆计算长度系数u查规范表5.3.3长细比λ=lo/i=查规范中的附表C可得φ=2.1组合风荷载的作用立杆底端的轴力N为N=(n×N1/2+N3)×1.2+0.85×(n'×N2/2)×1.4=风荷载作用下的立杆段弯距值M=0.85×1.4×wk×la×h2/10=立杆稳定性验算N/（φ×A）+M/W=[f]=205N/mm2满足要求2.2不组合风荷载的作用立杆底端的轴力为N=(n×N1/2+N3)×1.2+(n'×N2/2)×1.4=立杆稳定性验算N/（φ×A）=57.99满足要求有关参数的计算立杆自重N3=38.4×(H+(n-n'')×h)=计算长度lo=k×u×h=计算长度附加系数k长细比λ=lo/i=查规范中的附表C可得φ=3壁厚t其它杆3.53205206000表4.2.1-1脚手板自重标准值类别表4.2.1-2栏杆、挡脚板自重标准值敞开栏杆、冲压钢脚手板挡板表3.1.2脚手架钢管尺寸(mm)截面尺寸横向水平杆2200最大长度外径φ，d48516500栏杆、木脚手板挡板栏杆、竹串片脚手板挡板0.143表4.2.4脚手架的风荷载体型系数us标准值(kN/m2)0.11直角扣件、旋转扣件(抗滑)对接扣件(抗滑)0.14表4.2.2施工均布活荷载标准值类别标准值(kN/m2)装修脚手架2项目8.00承载力设计值3.20底座(抗压)40.00容许挠度[w]l/150与10mm脚手板，纵向、横向水平杆悬挑受弯构件构件类别表5.1.8受弯构件的容许挠度l/400类别冲压钢脚手板竹串片脚手板木脚手板标准值(kN/m2)0.30.350.35背靠建筑物的状况全封闭墙结构脚手架敞开、框架和开洞墙1.3ψ全封闭、半封闭表5.1.7扣件、底座的承载力设计值(kN)Q235钢抗拉、抗压和抗弯强度设计值f脚手架状况ustw1.0ψAn为挡风面积Aw为迎风面积ψ为挡风系数ψ=1.2An/Aw弹性模量E表5.1.6钢材的强度设计值与弹性模量(N/mm2)4横向斜撑、剪刀撑中的压杆外径φ，d(mm)壁厚t(mm)截面积A(cm2)惯性矩I(cm4)截面模量W(cm3)回转半径i(cm)每米长质量(kg/m)483.54.8912.195.081.583.84513.04.5213.085.131.703.55λ012345678901.0000.9970.9950.9920.9890.9870.9840.9810.9790.976100.9740.9710.9680.9660.9630.9600.9580.9550.9520.949200.9470.9440.9410.9380.9360.9330.9300.9270.9240.921300.9180.9150.9120.9090.9060.9030.8990.8960.8930.889400.8860.8820.8790.8750.8720.8680.8640.8610.8580.855500.8520.8490.8460.8430.8390.8360.8320.8290.8250.822600.8180.8140.8100.8060.8020.7970.7930.7890.7840.779700.7750.7700.7650.7600.7550.7500.7440.7390.7330.728800.7220.7160.7100.7040.6980.6920.6860.6800.6730.667900.6610.6540.6480.6410.6340.6260.6180.6110.6030.5951000.5880.5800.5730.5660.5580.5510.5440.5370.5300.5231100.5160.5090.5020.4960.4890.4830.4760.4700.4640.4581200.4520.4460.4400.4340.4280.4230.4170.4120.4060.4011300.3960.3910.3860.3810.3760.3710.3670.3620.3570.3531400.3490.3440.3400.3360.3320.3280.3240.3200.3160.3121500.3080.3050.3010.2980.2940.2910.2870.2840.2810.2771600.2740.2710.2680.2650.2620.2590.2560.2530.2510.2481700.2450.2430.2400.2370.2350.2320.2300.2270.2250.2231800.2200.2180.2160.2140.2110.2090.2070.2050.2030.2011900.1990.1970.1950.1930.1910.1890.1880.1860.1840.1822000.1800.1790.1770.1750.1740.1720.1710.1690.1670.1662100.1640.1630.1610.1600.1590.1570.1560.1540.1530.1522200.1500.1490.1480.1460.1450.1440.1430.1410.1400.139构件类别容许长细比[λ]双排架单排架拉杆210230250立杆3501.55≤1.501.801.751.801.50单排架2.00双排架表5.1.9受压、受拉构件的的容许长细比二步三跨表5.3.3脚手架立杆的计算长度系数u1.551.601.70表B钢管截面特性三步三跨类别立杆横距(m)连墙件布置表C稳定系数φ表1.051.3052300.1380.1370.1360.1350.1330.1320.1310.1300.1290.1282400.1270.1260.1250.1240.1230.1220.1210.1200.1190.1182500.117当λ＞250时，φ=7320/λ2ABCD1.171.000.740.621.381.000.740.621.521.140.740.621.631.250.840.621.801.421.000.621.921.561.130.732.031.671.250.842.121.771.350.932.201.861.451.022.271.951.541.112.342.021.621.192.402.091.701.27对接搭接35.713.933.11330.312.427.211.68090A类指近海海面和海岛、海岸、湖岸及沙漠地区；B类指田野、乡村、丛林、丘陵以及房屋比较稀疏的乡村和城市郊区；15地面粗糙度类别表7.2.1风压高度变化系数uz离地面高度(m)105立杆允许荷载[N]值(kN)10020304050C类指有密集建筑群的城市市区；D类指有密集建筑群且房屋较高的城市市区。6070125015001800φ48×3.5的钢管横杆步距L（mm）10006