4楼板设计.doc

4 楼板结构设计4 楼板结构设计4.1楼板计算方法的确定根据规范规定，计算本层楼板时，将长短边之比小于2.0的楼板视为双向板，将长短边之比大于2.0的楼板视为单向板，当长边与短边长度之比大于2.0，但小于3.0时，宜按双向板计算，楼板的编号见结构布置图（图4-1）。取二层楼板配筋为例。采用C30混凝土， N/mm2，钢筋采用HPB235，=210N/mm2，板面至钢筋中心轴厚板底长跨方向为30mm，短跨方向为20mm，板厚均为120mm。室内板顶标高一致。4.2弯矩计算（1）求跨中最大正弯矩跨中最大正弯矩发生在活荷载为棋盘式布置。计算时简化为：1、求内支座为固定，图4-1 结构布置图作用下的跨中弯矩；2、求内支座为铰支，作用下的跨中弯矩；3、求以上两种情况所求的跨中弯矩之和，得各内区格板跨中最大正弯矩。边区格板、角板，梁（边缘支座）对板的作用均视为铰支支座，计算方法同内区格板。4.3 板配筋计算楼板配筋计算，表4-1 表4-1 楼板配筋计算计算内容B1B2B3B4B5B6B7lx4.54.54.54.5334.5ly7.157.152.12.17.152.11.41lx/ly或ly/lx0.6293710.6293710.4666670.4666670.419580.70.3133333l4.54.52.12.1331.41g=gk*1.25.1965.1964.5844.5845.1964.5845.196q=qk*1.42.82.83.53.52.83.53.5g+q/26.5966.5966.3346.3346.5966.3346.946q/21.41.41.751.751.41.751.75g+q7.9967.9968.0848.0847.9968.0848.696实际支撑系数mx10.03790.00990.00380.04080.01130.00990.0099my10.03880.05340.040.00280.03210.05340.0534四边简支系数mx20.07950.01740.01740.09650.02960.01740.0174my20.050.09650.09650.01740.06830.09650.0965支座支撑系数mx-0.081-0.0784-0.057-0.0836-0.0569-0.0784-0.0784my-0.0571-0.1146-0.0829-0.0569-0.0735-0.1146-0.1146Mx=mx1(g+q/2)l2+mx2ql2/28.2837817.316090.4108210.240433.6379511.110370.1972501My=my1(g+q/2)l2+my2ql2/22.7851776.5999772.2363581.8620560.3854592.905621.0731593Mxv=Mx+0.2My8.8408168.6360860.8580920.6128413.7150431.691490.411882Myv=My+0.2Mx4.4419338.0631952.3185221.9101421.1130493.127691.1126093Mx=mx(g+q)l212.40313.115442.7949942.0320756.016194.139821.3554198My=my(g+q)l29.2455759.2455754.085542.9554214.0947525.347571.9812641h0100100808010080100跨中X方向s=M/a1fcbh00.0603920.0093760.0066960.0259790.018480.00288030.00288rs=0.5×（1+（1-2s)1/2)0.9688320.995290.9966410.9868370.990670.99855780.998558As=M/fyrsh0424.471951.3186336.60159179.2665101.63219.64175619.64176配筋491491491393393251251b1000100010001000100010001000h120100100120100120120配筋率=As/bh0.0040920.004910.004910.0032750.003930.00209170.002092Pmin0.20%0.20%0.20%0.20%0.20%0.20%0.20%h090907070907090跨中Y方向s=M/a1fcbh00.0696120.0330890.027260.0096090.044640.00960550.009606rs=0.5×（1+（1-2s)1/2)0.963890.9831730.9861790.9951720.977160.99517390.995174As=M/fyrsh0442.6067160.4221131.762859.17721217.74159.15369759.1537配筋436393393436393393251b1000100010001000100010001000h120100100120100120120配筋率=As/bh0.0036330.003930.003930.0036330.003930.0032750.002092Pmin0.20%0.20%0.20%0.20%0.20%0.20%0.20%h0100100808010080100支座X方向s=M/a1fcbh00.0917160.030540.0222040.0420710.045230.00947850.009478rs=0.5×（1+（1-2s)1/2)0.9518210.984490.9887720.9785020.976850.99523810.995238As=M/fyrsh0656.158168.9898122.3304292.7794252.25864.85262164.85262配筋665393393436393251251b1000100010001000100010001000h120100100120100120120配筋率=As/bh0.0055420.003930.003930.0036330.003930.00209170.002092Pmin0.20%0.20%0.20%0.20%0.20%0.20%0.20%h090907070907090支座Y方向s=M/a1fcbh00.079820.0583070.0421780.0353510.076320.01710490.017105rs=0.5×（1+（1-2s)1/2)0.9583560.9699430.9784460.9820.960260.99137310.991373As=M/fyrsh0510.4408286.5404205.4779220.6247378.834105.74101105.741配筋565565565393393393296b1000100010001000100010001000h120100100120100120120配筋率=As/bh0.0047080.005650.005650.0032750.003930.0032750.002467Pmin0.20%0.20%0.20%0.20%0.20%0.20%0.20%97