后张50mT梁张拉计算说明书.doc

后张50mT梁张拉计算说明书1、 根据公路桥涵施工技术规范第12.10章节后张法及附录G8预应力筋平均张拉力的计算章节。2、 根据济东高速公路两阶段施工图设计图纸。3、 根据本梁场张拉设备的实际结构设计，如下图：ADC梁中心 线BA、工具锚（外露50mm）B、200T穿心千斤顶360mm）C、限位板（外露30mm）D、工作锚具（外露50mm）每端限位板与千斤顶重合1cm4、计算钢绞线张拉时有效长度L及孔道长度X钢绞线张拉时有效长度L等于孔道长加上千斤顶及锚具和限位板外露部分的长度，而孔道长度X等于表中钢绞线长减去端部65厘米工作长度。本T梁张拉时采用两端对称同时张拉，所以取梁的中心截面及张拉端作为计算截面。由计算公式计算理论伸长量：P=P0(1-e-(kX+)/ (kX+)L= PL/(EA)式中：L预应力筋理论伸长值；P预应力筋的平均张拉力；L从张拉端至计算截面孔道长度；Ay预应力筋截面面积；根据检验报告取139mm2Eg预应力筋的弹性模量；根据检验报告取199GPaP0预应力筋张拉端的张拉力；0.75fpk=1395N从张拉端至计算截面曲线孔道部分切线的夹角之和；k孔道每米局部偏差对摩擦的影响系数；现场情况查表得0.001预应力筋与孔道壁的摩擦系数；现场情况查表得0.19 LB1=17.309-0.65+0.05+0.04+0.05+0.36 =17.159mXB1=16.659mLB2=20.307-0.65+0.05+0.04+0.05+0.36 =20.157mXB2=19.657 mLB3=23.316-0.65+0.05+0.04+0.05+0.36 =23.166mXB3=22.666LB4=25.477-0.65+0.05+0.04+0.05+0.36 =25.327mXB4=24.827LB5=25.358-0.65+0.05+0.04+0.05+0.36 =25.208mXB5=24.708mLB6=25.374-0.65+0.05+0.04+0.050.36 =25.224mXB6=24.724m1、PPB1=P(1-e-(kXB1+)/ (kXB1+) =1395139(1- e-(0.00116.659+0.190.2617) / （0.00116.659+0.190.2617)=1395139(0.0642/0.0664) =187.61KN L1= PPB1LB1/(EPAP)=187.6117.159/(199139)=116mm 理论119mm2、PPB2=P(1-e-(kXB2+)/ (kXB2+) =1395139(1- e-(0.00119.657+0.190.2617) / (0.00119.657+0.190.2617)=1395139(0.0670/0.0694) =187.332KN L2= PPB2LB2/(EPAP)=189.33220.157/(199139)=138mm 理论139mm3、PPB3=P(1-e-(kXB3+)/ (kXB3+) =1395139(1- e-(0.00122.666+0.190.2617) / (0.00122.666+0.190.2617)=1395139(0.0698/0.0724) =186.942KN L3= PPB3LB3/(EPAP)=186.94223.166/(199139)=159mm 理论160mm4、PPB4=P(1-e-(kXB4+)/ (kXB4+) =1395139(1- e-(0.00124.8270.190.1744) / (0.00124.827+0.190.1744)=1395139(0.0563/0.0580) =188.222KN L4= PPB4LB4/(EPAP)=188.22225.327/(199139)=172mm 理论172mm5、PPB5=P(1-e-(kXB5+)/ (kXB5+) =1395139(1- e-(0.00124.7080.190.0785) / (0.00124.708+0.190.0785)=1395139(0.0388/0.0396) =189.988KN L5= PPB5LB5/(EPAP)=189.98825.208/(199139)=173mm 理论172mm6、PPB6=P(1-e-(kXB6+)/ (kXB6+) =1395139(1- e-(0.00124.7240.190.0785) / (0.00124.724+0.190.0785)=1395139(0.0389/0.0396) =190.477KN L6= PPB6LB6(EPAP)=190.47725.224/(199139)=174mm 理论172mm张拉油表读数计算：F= kAgn0.001bF预应力筋的张拉力，Kn；k预应力筋的张拉控制应力，MPa；Ag每根预应力筋的截面面积，mm2；n同时张拉预应力筋根数；b超张拉系数，不超拉时取1.0。T梁预应力钢筋张拉力计算：S1、：8根钢绞线张拉力：F1 =10%kAgn0.001b =10%139513980.0011.0 =155.12KNF2 =20%kAgn0.001b =20%139513980.0011.0 =310.25 KNF3 =50%kAgn0.001b =50%139513980.0011.0 =775.62 KNF4=100%kAgn0.001b =100%139513980.0011.0 =1551.24KN：7根钢绞线张拉力：F1 =10%kAgn0.001b =10%139513970.0011.0 =135.73KNF2 =20%kAgn0.001b =20%139513970.0011.0 =271.47KNF3 =50%kAgn0.001b =50%139513970.0011.0 =678.67KNF4 =100%kAgn0.001b =100%139513970.0011.0 =1357.34KNT梁预应力张拉油表读数（、）千斤顶编号回归线方程F=10%控F=20%控F=50%控F=100%控155.12310.25775.621551.241号W1319P=0.02904F+1.225.7210.2323.7446.272号W1327P=0.02974F+1.215.8210.4424.2847.34T梁预应力张拉油表读数（）千斤顶编号回归线方程F=10%控F=20%控F=50%控F=100%控135.73271.47678.67135