高杆灯基础计算书.doc

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1、中杆灯支架基础计算一、设计参数钢筋混凝土容重：γ砼＝25kN/m3，钢容重：γ钢＝78.5kN/m3；地下水位按地面以下0.5m考虑；50年一遇风压：0.60kN/m2；灯具总重：3.8吨二、计算简图三、荷载计算1恒载=灯具共设8个投光灯，均布在灯杆顶部圆盘上G1＝3.8*10＝38kN2活载=灯杆风荷载灯杆半高处截面外径d=(250+560)/2=405mm风压高度变化系数：地面粗糙类别B类，灯杆高度H=30m，μz＝1.39风荷载体形系数：μzw0d2＝1.39*0.60*0.405*0.405＝0.137≥0.015，且⊿≈0，H/d＝30/0.405＝74

2、>25，故μs＝0.6H2/d=30*30/0.405=2222>700T=0.25+0.99*10-3*H2/d=2.45s>0.25s根据规范应考虑风压脉动对结构产生顺风向风振的影响。脉动分风荷载的空间相关系数确定：根据规范，对迎风面宽度较小的高耸结构，水平方向相关系数可取ρx=1竖直方向的相关系数=0.8427脉动风荷载的背景分量因子对于迎风面和侧风面的宽度沿高度按直线变化的高耸结构，应乘以修正系数=0.447，=1.928，，按下表确定：表1修正系数zB(z)B(0)θB35295600.94564985600.88994675600.8341243656

3、00.779154055600.723183745600.668213435600.613243125600.557272815600.502302505600.446表2脉动风荷载的背景分量因子zHka1ρxρzψzuzBz1θBθvBz3300.910.21810.8430.0210.0320.9451.9280.0596300.910.21810.8430.0610.0970.8891.9280.1669300.910.21810.8430.1410.2250.8341.9280.36212300.910.21810.8430.231.0520.3520.7

4、791.9280.52815300.910.21810.8430.341.130.4840.7231.9280.67518300.910.21810.8430.461.190.6220.6681.9280.80121300.910.21810.8430.591.2460.7620.6131.9280.90024300.910.21810.8430.791.2940.9830.5571.9281.05627300.910.21810.8430.861.3421.0320.5021.9280.99830300.910.21810.84311.391.1580.4461

5、.9280.997脉动风荷载的共振分量因子R=2.876z高度处的风振系数取值见下表：表3风振系数取值BzRIgβz0.0592.8760.142.51.1250.1662.8760.142.51.3530.3622.8760.142.51.7720.5282.8760.142.52.1260.6752.8760.142.52.4390.8012.8760.142.52.7080.9002.8760.142.52.9181.0562.8760.142.53.2500.9982.8760.142.53.1270.9972.8760.142.53.124zusuzβz

6、w0wk直径D(m)水平力F（kN)作用长度L(m）弯矩M（kN*m）30.611.1250.60.4050.54450.6621.50.99260.611.3530.60.4870.51350.7504.53.37690.611.7720.60.6380.48250.9247.56.926120.61.0522.1260.60.8050.45151.09110.511.451150.61.132.4390.60.9920.42051.25213.516.900180.61.192.7080.61.1600.38951.35516.522.364210.61.24

7、62.9180.61.3090.35851.40819.527.454240.61.2943.2500.61.5140.32751.48722.533.467270.61.3423.1270.61.5110.29651.34425.534.266300.61.393.1240.61.5630.26551.24528.535.491灯杆所受风荷载水平力F1=11.52KN,弯矩M1=192.69KN*m=灯具风荷载表4灯具风荷载w0(kN/m2)μsμzβzwk(kN/m2)灯具面积A(m2)水平力F2（kN)作用长度L(m）弯矩M（kN*m）0.61.31.393

8、.1243