20m預(yù)應(yīng)力箱梁張拉施工方案

N拉過(guò)程(一)預(yù)應(yīng)力筋張拉程序(二)理論伸長(zhǎng)值計(jì)算根鋼絞線。按設(shè)計(jì)規(guī)定孔道采用金屬波紋管，按后張法預(yù)應(yīng)力曲線兩端張拉規(guī)定進(jìn)式中：PP—各分段預(yù)應(yīng)力筋的平均張拉力(N)，直線筋取張拉端的拉力，兩P—預(yù)應(yīng)力筋張拉端的張拉力(N)；χ—從張拉端至計(jì)算截面的孔道長(zhǎng)度(m)；角之和(rad)；L—預(yù)應(yīng)力筋的分段長(zhǎng)度(mm)；AP—預(yù)應(yīng)力筋的截面面積(mm2)；EP—預(yù)應(yīng)力筋的彈性模量(N/mm2)；(1)N1束：AR=3000B288.053.75.5°CDL=638.3(cm)=6383(mm)AP=140×4(mm2)EP5(N/mm2)LAB=45.4(mm)=773744(1-e-(0.0015×2.880+0.25×0.09599))/(0.0015×2.880+0.25×62891(N)CDeCDeX=L=53.7(cm)=0.537(m)AP=140×4(mm2)0(mm)1ABBCCD總計(jì)：N伸長(zhǎng)量△L=(△L+△L1ABBCCD=(45.4+20.12+3.70)×2=138(mm)2(2)N束2AR=3000CDLX=492.5(cm)=4925(mm)AP=140×4(mm2)EP(N/mm2)PPPAekxkxe.0015×4.925)/(0.0015×4.925)△L=△L==20.16(mm)CDCCDCX＝L=201.5(cm)=2.015(m)AP=140×4(mm2)=13.89(mm)2ABBCCD總計(jì)N的伸長(zhǎng)量△L=(△L+△L2ABBCCD=(35.1+20.16+13.89)×2=138(mm)(3)N3束CDABAABAX=L=106.6(cm)=1.066(m)AP=140×3(mm2)EP(N/mm2)PP=PA(1-e-kx)/kx＝1395×140×3×(1-e-0.0015×1.066)/(0.0015×1.066)△LAB=140×3×1.95×105＝7.62(mm)=584964(1-e-(0.0015×0.733+0.25×0.02443))/(0.0015×0.733+0.25×82861(N)=5.22(mm)CDCCDCX＝L=790.1(cm)=7.901(m)AP=140×3(mm2)55.7(mm)3ABBCCD總計(jì)N的伸長(zhǎng)量△L=(△L+△L3ABBCCD=(7.62+5.22+55.7)×2m(1)N1束：A480.7R=3000BCDABAABAX＝L=480.7(cm)=4.807(m)AP=140×5(mm2)EP5(N/mm2)△L.26(mm)BCmmCDCCDCX=L=2128(mm)=2.128(m)AP=140×5(mm2)eN14.67(mm)1ABBCCD總計(jì)：N伸長(zhǎng)量△L=(△L+△L1ABBCCD=(34.26+20.17+14.67)×2=138(mm)2(2)N束2ACDCABAABAX＝L=335.8(cm)=3.358(m)AP=140×5(mm2)EP(N/mm2)PPPAekxkx(1-e-0.0015×3.358)/(0.0015×3.358)△LAB=140×5×1.95×105＝23.96(mm)=20.21(mm)CDCCDCX＝L=358.2(cm)=3.582(m)AP=140×5(mm2)D=24.71(mm)2ABBCCD總計(jì)N的伸長(zhǎng)量△L=(△L+△L2ABBCCD=(23.96+20.21+24.71)×2=138(mm)3(3)N束3CDABAABAX=L=101.7(cm)=1.017(m)AP=140×4(mm2)EP(N/mm2)PP=PA(1-e-kx)/kx＝1395×140×4×(1-e-0.0015×1.017)/(0.0015×1.017)7△LAB=140×4×1.95×105＝7.27(mm)=5.22(mm)CDCCDCX＝L=800(cm)=8(m)AP=140×4(mm2)=56.39(mm)2ABBCCD總計(jì)N的伸長(zhǎng)量△L=(△L+△L2ABBCCD=(7.27+5.22+56.39)×2=138(mm)三、張拉順序圖1212N′N22N′2N332N1N2N3320m箱梁預(yù)應(yīng)力控制梁梁錨下控制力力3力23力時(shí)23計(jì)伸長(zhǎng)量NN1781.156.781.38.37.81378.123.943.807.807.581′22426729中NN2781.156.781.38.37.81378.123.943.807.807.58跨2′22426728NN3585.117.585.29.28.358.592.972.865.875.691373′9189027N1端跨N2′′523527298NNN3781.156.781.38.37.81378.123.943.807.807.583′2242672810%~20%時(shí)的伸長(zhǎng)值作為初應(yīng)力以下的推算伸長(zhǎng)值。施工中按“理論伸長(zhǎng)值=實(shí)測(cè)伸長(zhǎng)值+初應(yīng)力以下的推算伸長(zhǎng)值”進(jìn)行值之差必須控制在±6%以