20箱梁預(yù)應(yīng)力張拉報告

1、南水渠中橋20m預(yù)應(yīng)力砼箱梁預(yù)應(yīng)力鋼絞線張拉理論伸長量復(fù)核一、張拉力的計算（依據(jù)圖紙資料）控制應(yīng)力k=1395.0Mpa,初張拉應(yīng)力0.1k =139.5Mpa,單根270級（1860Mpa）s15.24mm鋼絞線面積A=140mm2,張拉力：Nk=N·A·k1、 正彎矩區(qū)：中跨N1與邊跨N1、N2、N3、N4張拉鋼絞線為一束4根組成；中跨N2、N3張拉鋼絞線均為一束3根組成。2、 中跨N1與邊跨N1、N2、N3張拉力：控制張拉應(yīng)力k =N·A·k=4·140·1395=781200N=781.2KN 初張拉應(yīng)力0.1k=0.1

2、83;781.2=78.12 KN中跨N2、N3張拉力：控制張拉應(yīng)力k =N·A·k=3·140·1395=585900N=585.9KN 初張拉應(yīng)力0.1k=0.1·585.9=58.59KN2、負彎矩區(qū)：T1張拉鋼絞線為一束5根組成；T2、T3張拉鋼絞線為一束4根組成。 T1張拉力：控制張拉應(yīng)力k =N·A·k=5·140·1395=976500N=976.5KN 初張拉應(yīng)力0.1k=0.1·976.5=97.65KN T2、T3張拉力：控制張拉應(yīng)力k =N·A·k=4&

3、#183;140·1395=781200N=781.2KN 初張拉應(yīng)力0.1k=0.1·781.2=78.12KN設(shè)計張拉力匯總部位邊跨中跨正彎矩 張拉力（N）N1N2N3N1N2N3781200585900585900781200781200781200負彎矩 張拉力（N）T1T2T3976500781200781200二、伸長量計算1、平均張拉力計算依據(jù)規(guī)公式Pp=(P×（1-e-（kx+）)/（kx+）查規(guī)范附表G-8得K=0.0015，=0.25A、邊跨：N1#:取x= 9.814 m =5。30= 0.095993rad p=781200Pp=（7812

4、00×（1-e-（0.0015×9.814+0.25×0.95993）/（0.0015×9.814+0.25×0.095993）=766277NN2#:取x= 9.819m =5。30= 0.095993rad p=781200Pp=（781200×（1-e-（0.0015×9.819+0.25×0.095993）/（0.0015×9.819+0.25×0.095993）=766267NN3#:取x= 9.751m =1。24=0.024439rad p=781200Pp=（781200

5、5;（1-e-（0.0015×9.751+0.25×0.024439）/（0.0015×9.751+0.25×0.095993）=773156NB、中跨：N1#:取x= 9.801m =5。30= 0.095993rad p=781200Pp=（781200×（1-e-（0.0015×9.801+0.25×0.09553）/（0.0015×9.801+0.25×0.095993）=766277NN2#:取x=9.818m =5。30= 0.024435rad p=585900Pp=（585900×

6、;（1-e-（0.0015×9.818+0.25×0.024435）/（0.0015×9.818+0.25×0.024435）=579838NN3#:取x= 9.701m =1。24= 0.087267rad p=585900Pp=（585900×（1-e-（0.0015×9.701+0.25×0.087267）/（0.0015×9.701+0.25×0.087267）=579889NC負彎矩：T1 #:取x=3.0m =0。= 0rad p=976500Pp=（976500×（1-e-（0.0

7、015×3.0+0.25×0）/（0.0015×3.0+0.25×0）=974306NT2 #:取x=3.0m =0。= 0rad p=781200Pp=（781200×（1-e-（0.0015×6.65+0.25×0）/（0.0015×3.0+0.25×0）=779445NT2 #:取x=6.50m =0。= 0rad p=781200Pp=（781200×（1-e-（0.0015×6.50+0.25×0）/（0.0015×6.50+0.25×0）=77

8、7404N鋼絞線束號X (m) (rad)kx+e-（kx+）P (N)Pp (N)邊跨N19.8140.0959930.03870.96204781200766572N29.8190.0959930.02080.97941781200766267N39.7510.0244390.02070.97951781200773156中跨N19.8010.0959930.03870.96204 781200766277N29.8180.0244390.03870.96204585900579838N39.7010.0244390.02070.97951585900579889負彎矩T13.0 00.0

9、045 0.99551976500974306T23.0 00.0045 0.99551781200779445T36.5 00.0098 0.990257812007774042、伸長量計算：依據(jù)規(guī)范公式L=（Pp×L）/（Ap×Ep）A邊跨：一端伸長量已知：Ep=195×103MpaN1# L= 10464 Pp=766270N Ap=140×4mm2 L=（766270×10464）/（560×195000）=73.43mm=7.343cmN2# L= 10496 Pp=766267N Ap=140×4mm2 L=（7

10、66267×10496）/（560×195000）=73.65mm=7.365cmN3# L=10401 Pp=773156N Ap=140×4mm2 L=（773156×10401）/（560×195000）=73.64mm=7.364cm總伸長量：N1# 2L=2×7.343=14.69cmN2# 2L=2×7.365=14.73cmN3# 2L=2×7.364=14.73cmB中跨：一端伸長量已知：Ep=195×103MpaN1# L=10451 Pp=766277N Ap=140×4mm

11、2 L=（766277×10451）/（560×195000）=73.34mm=7.33cmN2# L=10468 Pp=579838N Ap=140×3mm2 L=（579838×10468）/（420×195000）=74.11mm=7.41cmN3# L=10351 Pp=579889N Ap=140×3mm2 L=（579889×10351）/（420×195000）=73.29mm=7.33cm總伸長量：N1# 2L=2×7.33=14.66cmN2# 2L=2×7.41=14.82c

12、mN3# 2L=2×7.33=14.66cmC負彎矩：一端伸長量已知：Ep=195×103MpaT1# L=3300 Pp=974306N Ap=140×5mm2 L=（974306×3300）/（700×195000）=23.55mm=2.355cmT2# L= 3300 Pp=779445N Ap=140×4mm2 L=（779445×3300）/（560×195000）=23.55mm=2.355cmT3# L= 6800 Pp=777404N Ap=140×4mm2 L=（7774047×6800）/（560×195