40mT梁预应力张拉计算书

新平县大开门至戛洒高速公路工程 40mT梁预制施工技术方案8、附件8.1 40mT梁预应力张拉计算书8.1.1编制依据1、新平县大开门至戛洒高速公路两阶段施工图设计；2、公路桥涵施工技术规范（JTJ041-2011）；3、预应力混凝土用钢绞线（GB/T5224-2003）。8.1.2材料准备根据设计图纸，该工程所用预应力钢绞线为高强度低松弛7丝捻制的预应力钢绞线，公称直径为15.2mm公称面积为140mm2，标准强度为fpk=1860Mpa,弹性模量Ep=1.95105，松弛系数为0.3。8.1.3控制应力及伸长值计算1、张拉控制应力单根锚端张拉控制应力为：k=0.75fpk=0.751860=1395Mpa；单根钢绞线张拉控制力为：P=1395140/1000=195.3KN，正弯矩钢束主要设计参数如下：40米T梁类别T梁位置钢束编号钢束类型根/束控制拉力KN/束梁体张拉时计算上拱度（mm）边跨（一端简支一端连续）中板N115S15.22929.514.1N215S15.22929.5N36S15.21172边板N116S15.2312514.1N216S15.23125N36S15.21172中跨 （两端连续） 中板N113S15.2253914N213S15.22539N36S15.21172边板N115S15.22929.514N213S15.22539N36S15.211722、后张法钢绞线理论伸长值计算公式说明L=pL/ Ap Epp=P(1-e-(k x +)k x +式中：P-预应力筋张拉端的张拉力，单位：KN。 L-预应力筋长度，单位：mm。 Ep-预应力筋弹性模量，单位：N/mm2。 Ap-预应力筋截面面积，单位：mm2。 x丛张拉端至计算截面的孔道长度，单位：m。 从张拉端至计算截面曲线孔道部分切线的夹角之和，单位：rad。 k孔道每米局部偏差对摩擦的影响系数，取0.0015。 预应力筋与孔道壁的摩擦系数，取0.155。每段的终点力与起点力的关系如下式：Pz=Pqe-(k x +) Pz分段终点力（N）Pq分段的起点力（N）、L、k、意义同上将钢束分三段（半幅）图1：3、伸长值计算本计算选取大尖山大桥左幅第1跨边梁进行计算，其余预应力筋理论伸长量用电脑Excel编程计算单根锚端张拉控制应力为：k=0.75fpk=0.751860=1395Mpa单根钢绞线张拉控制力为:P=1395140/1000=195.3KN N1刚束:P1=195.316=3124.8KNN2刚束:P2=195.316=3124.8KNN3刚束:P3=195.36=1171.8 KN（1）、边跨边梁1）、N1钢束张拉伸长量计算a、AB段直线段L=14.73m；Pq（AB）=P=3124.8KNp=P(1-e-(k x +)/ (k x +)= 3124.8KN(1- e-(0.001514.73+0.1550)/ (0.0015 14.73 +0.1550)=3090.53KNLAB=pL/ ApEp =3090.53KN100014.73m1000/(161401950000)=104.2mmb、BC段曲线段L=1.834m；Pq（BC） =Pz(AB)=Pe-(k x +)=3124.8KNe-(0.001514.73 +0.1550)= 3056.51KNp= Pq (1-e-(k x +)/ (k x +)= 3056.51KN(1- e-(0.00151.834+0.1550.095993)/ (0.00151.834+0.1550.095993)=3029.73KNLBC=pL/ ApEp =3029.73KN10001.834m1000/(16140195000)=12.72mmc、CD段直线段L=3.068m；Pq(CD）=Pz(BC)=Pq(BC)e-(k x +)= 3056.51KNe-(0.00151.834 +0.1550.095993)=3003.10KNp= Pq (1-e-(k x +)/ (k x +)= 3003.10KN(1- e-(0.00153.068+0.1550)/ (0.00153.068+0.1550)=2996.2KNLCD=pL/ ApEp =2996.2KN10003.0681000m/(16140195000)=21.0mmL=LAB+LBCLCD=(104.2+12.7+21)*2=275.6mm2）、N2钢束张拉伸长量计算a、AB段直线段L=10.766m；Pq（AB）=P=3124.8KNp=P(1-e-(k x +)/ (k x +)= 3124.8KN(1- e-(0.001510.766+0.1550)/ (0.0015 10.766 +0.1550)=3099.7KNLAB=pL/ ApEp =3099.7KN100010.766m1000/(161401950000)=76.4mmb、BC段曲线段L=1.834m；Pq（BC） =Pz(AB)=Pe-(k x +)=3124.8KNe-(0.001510.766 +0.1550)= 3074.74KNp= Pq (1-e-(k x +)/ (k x +)= 3074.74KN(1- e-(0.00151.834+0.1550.095993)/ (0.00151.834+0.1550.095993)=3047.79KNLBC=pL/ ApEp =3047.79KN10001.834m1000/(16140195000)=12.8mmc、CD段曲线段L=7.068m；Pq(CD）=Pz(BC)=Pq(BC)e-(k x +)= 3074.74KNe-(0.00151.834 +0.1550.095993)=3020.99KNp= Pq (1-e-(k x +)/ (k x +)= 3020.99KN(1- e-(0.00157.068+0.1550)/ (0.00157.068+0.1550)=3005.0KNLCD=pL/ ApEp =3005.0KN10007.0681000m/(16140195000)=48.6mmL=LAB+LBCLCD=(76.4+12.8+48.6)*2=275.6mm3）、N3钢束张拉伸长量计算a、AB段直线段L=5.028m；Pq（AB）=P=1171.8KNp=P(1-e-(k x +)/ (k x +)= 1171.8KN(1- e-(0.00155.028+0.1550)/ (0.0015 5.028 +0.1550)=1167.39KNLAB=pL/ ApEp =1167.39KN10005.028m1000/(61401950000)=35.8mmb、BC段曲线段L=1.834m；Pq（BC） =Pz(AB)=Pe-(k x +)=1171.8KNe-(0.00155.028 +0.1550)=1163.0KNp= Pq (1-e-(k x +)/ (k x +)=1163.0KN(1- e-(0.00151.834+0.1550.095993)/ (0.00151.834+0.1550.095993)=1152.81KNLBC=pL/ ApEp =1152.81KN10001.834m1000/(6140195000)=12.9mmc、CD段曲线段L=12.832m；Pq(CD）=Pz(BC)=Pq(BC)e-(k x +)=1163KNe-(0.00151.834 +0.1550.095993)=1142.7KNp= Pq (1-e-(k x +)/ (k x +)= 1142.7KN(1- e-(