大西箱梁張拉計(jì)算及控制程序dx

1、大西鐵路客運(yùn)專線站前-15標(biāo)臨潼制梁場后張法箱梁預(yù)制每束預(yù)應(yīng)力鋼束張拉力、伸長值計(jì)算書一、 張拉力計(jì)算新建大同至西安鐵路客運(yùn)專線的雙線整孔簡支箱梁采用后張法施工,預(yù)應(yīng)力主筋設(shè)計(jì)采用符合1×7- 15.2 -1860 -GB/T5224 - 2003 標(biāo)準(zhǔn)的高強(qiáng)低松弛鋼絞線,截面積為 140mm2 , 鋼絞線標(biāo)準(zhǔn)強(qiáng)度為RY=1860MPa,EP=1.95×105MPa（實(shí)測平均值）。錨外控制應(yīng)力con為 1339.2至1372.43MPa之間,張拉使用四臺YCD350-200 型液壓千斤頂在梁兩端對稱張拉。鋼絞線孔道采用橡膠抽拔管成型。 二、伸長量計(jì)算 計(jì)算公式：1）鋼絞線張

2、拉伸長量計(jì)算公式L= ( PP ×L)/ ( EP ×AP)式中:PP 預(yù)應(yīng)力筋平均張拉力,N；L 理論伸長值,mm；L 預(yù)應(yīng)力筋的長度,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 ,根據(jù)試驗(yàn)報(bào)告取平均值。2）平均張拉力計(jì)算公式PP = P (1 - e - ( kx +) ) / ( kx +)式中:PP 預(yù)應(yīng)力筋平均張拉力,N；P 預(yù)應(yīng)力筋的錨下或分段計(jì)算時(shí)扣除上一段損失后的張拉力,N；x 從張拉端至計(jì)算截面的孔道長度,m；從張拉端至計(jì)算截面曲線孔道部分切線的夾角之和,rad ；k 孔道每米局部偏差對摩擦的影響系數(shù),取K=0.0015

3、；預(yù)應(yīng)力筋與孔道壁的摩擦系數(shù),參考實(shí)際圖取0.55。3) 錨下張拉力計(jì)算公式P = Pw(1 z ) 式中: Pw預(yù)應(yīng)力筋的錨外張拉控制力,N(由設(shè)計(jì)圖提供)；P 預(yù)應(yīng)力筋的錨下張拉力,N；z 預(yù)應(yīng)力筋與錨口及喇叭口的摩擦損失率,%(由試驗(yàn)結(jié)果確定，當(dāng)無試驗(yàn)數(shù)據(jù)時(shí)可采用設(shè)計(jì)的考慮值6%)；4) 分段計(jì)算時(shí)該段起點(diǎn)的張拉力計(jì)算公式P = Pz ×e - ( kx +) 式中: Pz分段計(jì)算時(shí)預(yù)應(yīng)力筋的上一段的計(jì)算張拉控制力,N；P 分段計(jì)算時(shí)計(jì)算段起點(diǎn)處的預(yù)應(yīng)力筋張拉力取值,N；k、x、與2公式相同,系指上一計(jì)算段的相關(guān)參數(shù)；預(yù)應(yīng)力筋的張拉程序：0 初始應(yīng)力(0.2倍con)con (

4、持荷5 min 錨固) 。由于在客運(yùn)專線后張法混凝土預(yù)制梁的預(yù)應(yīng)力錨固體系采用自錨式拉絲體系，夾片式具有自錨性能的錨具；因此根據(jù)實(shí)際張拉情況,當(dāng)千斤頂將鋼絞線張拉到con持荷5min回放時(shí),錨具直接將鋼絞線鎖住,但應(yīng)嚴(yán)格控制預(yù)應(yīng)力筋及夾片回縮容許值不許超過6mm,兩端不同步率不超過10%。對由多曲線段或直線與曲線段組成的曲線筋張拉伸長量應(yīng)分段計(jì)算，然后疊加，在計(jì)算時(shí)應(yīng)將每段兩端扣除孔道的摩阻損失后的拉力求出，然后再計(jì)算每段的張拉伸長值。現(xiàn)以通橋20082322A-II圖31.5m梁預(yù)應(yīng)力鋼束N1b號束為例進(jìn)行計(jì)算：參數(shù)的取定：，根據(jù)設(shè)計(jì)說明=0.55、K=0.0015。L/2ABC40D圖中：

5、=4°/180×=0.0698radAB=3.168+0.698（千斤頂及延伸筒）=3.866m CD=11.704m BC=1.047m線段L（米）（rad）kx+e-(kx+)終點(diǎn)力（KN）L（mm）ab3.86600.0057985750.9942182051581.55865624.88bc1.0470.06980.0399665620.9608215671545.8801696.58cd11.70400.0175560.9825972091501.97129871.552）第一段伸長值計(jì)算(斜直段長度)：錨下張拉控制力：P = Pw(1z ) = 1339.2&#

6、215;140×12×(1-6%)/1000= 1586.15 kN 平均張拉力計(jì)算:PP =P(1 - e - ( kx +) ) /(kx +) = 1586.15×(1-e-(0.0015×3.866)/(0.0015×3.866)= 1581.561kN 該段鋼絞線伸長量：L = ( PP×L) / ( EP ×AP)=1581.56×3.866/(195×140×9)×1000 =24.88mm3）第二段伸長值計(jì)算(圓弧段長度)：起點(diǎn)處張拉控制力：P = Pz &#

7、215;e - ( kx +)= 1586.15×e-(0.0015×3.866) = 1576.978 kN 平均張拉力計(jì)算: PP= P(1 - e - ( kx +) ) /(kx +)   = 1576.978×(1-e-(0.0015×1.047+0.55*0.0698)/ (0.0015×1.047+0.55×0.0698)= 1545.88 kN 該段鋼絞線伸長量：L = ( PP×L) / ( EP ×AP)= 1545.88×1.047/(195×

8、140×9)×1000 =6.58mm4）第三段伸長值計(jì)算(平直段長度)：起點(diǎn)處張拉控制力：P = Pz ×e - ( kx +)= 1576.978×e-(0.0015×1.047+0.55*0.0698)= 1515.194 kN 平均張拉力計(jì)算: PP = P(1- e - ( kx +) ) / ( kx +) = 1515.194×(1-e-(0.0015×11.704)/ (0.0015×11.704)=1501.971 kN 該段鋼絞線伸長量：L = (PP ×L) / ( EP

9、×AP)=1501.971×11.704/(195×140×9)×1000 =71.55mm由于上述過程是采用兩端張拉計(jì)算出的結(jié)果，N1束的錨下預(yù)應(yīng)力鋼絞線伸長值應(yīng)為：L=（24.88+6.58+71.55）×2 = 206.03 mm （設(shè)計(jì)值為197.2mm）其它鋼束伸長量計(jì)算：N1a伸長量張拉力為：1339.2×12×140=2249.86KN線段L（米）（rad）kx+e-(kx+)終點(diǎn)力（KN）L（mm）ab3.86600.0057980.9942182108.7424.88bc1.0460.0

10、6980.0399660.9608212061.176.58cd11.70400.0175560.9825972002.6371.55L=（24.88+6.58+71.55）*2=206.03mm （設(shè)計(jì)值為197.2mm）N2a、N2c伸長量張拉力為：1339.2×9×140=1687.39KN線段L（米）（rad）kx+e-(kx+)終點(diǎn)力（KN）L（mm）ab4.11600.0061740.9938441581.26126.49bc1.0460.06980.0399660.9608221545.2996.58cd11.70400.0175560.9825971501.

11、40771.52L=（26.49+6.58+71.52）*2=209.18mm （設(shè)計(jì)值為200.4mm）N2b、N2d伸長量 張拉力為：1339.2×9×140=1687.39KN線段L（米）（rad）kx+e-(kx+)終點(diǎn)力（KN）L（mm）ab4.11600.0061740.9938442108.3526.49bc1.0460.06980.0399660.9608222060.396.58cd11.70400.0175560.9825972001.8771.52L=（25.49+6.58+71.52）*2=209.18mm （設(shè)計(jì)值為200.4mm）N3伸長量張拉力

12、為：1372.43×9×140=1729.26KN線段L（米）（rad）kx+e-(kx+)終點(diǎn)力（KN）L（mm）ab2.51300.0037690.9962371622.4416.60bc2.1030.13960.0799490.9231631556.3413.32cd0.79500.0011920.9988081494.064.83de2.2790.11340.0658150.9363031445.1013.41ef9.23200.0138480.9862471388.4352.17 L=（16.60+13.32+4.83+13.41+52.17）*2=206.6mm

13、 （設(shè)計(jì)值為189.2mm）N4伸長量張拉力為：1342.75×9×140=1692.12KN線段L（米）（rad）kx+e-(kx+)終點(diǎn)力（KN）L（mm）ab2.62400.0039360.9960711587.4616.95bc1.0530.06980.0399760.9608111553.096.66cd1.72000.0025800.9974201520.2910.64de2.2790.11340.0658150.9363031469.4513.64ef9.23200.0138480.9862471411.8253.05L=（16.95+6.66+10.64+1

14、3.64+3.05）*2=201.88mm （設(shè)計(jì)值為190.5mm）N5伸長量張拉力為：1372.43×9×140=1729.26KN線段L（米）（rad）kx+e-(kx+)終點(diǎn)力（KN）L（mm）ab2.51300.0037690.9962371622.4416.59bc2.1030.1396260.0799490.9231631556.3413.32cd3.35700.0050360.9949761491.2020.38de2.2790.1134460.0658150.9363031439.5513.35ef6.68600.0100290.9900211385.74

15、37.71 L=（16.59+13.32+20.38+13.35+37.71）*2=202.7mm （設(shè)計(jì)值為191.8mm）N6伸長量張拉力為：1342.95×9×140=1692.12KN線段L（米）（rad）kx+e-(kx+)終點(diǎn)力（KN）L（mm）ab2.62400.0039360.9960711587.4616.95bc1.0520.06980.0399760.9608111553.096.65cd4.28200.0064230.9935961517.3726.45de2.2790.11340.0658150.9363031463.8013.58ef6.6860

16、0.0100290.9900211409.0838.34 L=（16.95+6.65+26.45+13.58+38.34）*2=203.94mm （設(shè)計(jì)值為193.2mm）N7伸長量張拉力為：1372.43×9×140=1729.26KN線段L（米）（rad）kx+e-(kx+)終點(diǎn)力（KN）L（mm）ab2.51300.0037690.9962371622.4416.59bc2.1030.13960.0799490.9231631556.3413.32cd5.9100.0088780.9911611488.3435.86de2.2790.11340.0658150.936

17、3031434.0313.31ef4.14100.0062110.9938071383.0623.31 L=（16.59+13.32+35.86+13.31+23.31）*2=204.78mm （設(shè)計(jì)值為194.5mm）N8伸長量張拉力為：1342.95×9×140=1692.12KN線段L（米）（rad）kx+e-(kx+)終點(diǎn)力（KN）L（mm）ab2.62400.0039360.9960711587.4616.96bc1.0530.06980.0399760.9608111553.096.66cd6.84300.0102650.9897861514.4642.18de

18、2.2790.11340.0658150.9363031458.1913.53ef4.14100.0062110.9938071406.3623.70 L=（16.96+6.66+42.18+13.53+23.7）*2=206.05mm （設(shè)計(jì)值為195.9mm）N9伸長量張拉力為：1372.43×9×140=1729.26KN線段L（米）（rad）kx+e-(kx+)終點(diǎn)力（KN）L（mm）ab2.51300.0037690.9962371622.4416.60bc2.1030.13960.0799490.9231631556.3413.32cd8.48100.01272

19、00.9873591485.4951.27de2.2790.11340.0658150.9363031428.5413.26ef1.59600.0023940.9976081380.398.97 L=（15.60+13.32+51.27+13.26+8.97）*2=206.82mm （設(shè)計(jì)值為197.2mm）N10伸長量張拉力為：1342.95×9×140=1692.12KN線段L（米）（rad）kx+e-(kx+)終點(diǎn)力（KN）L（mm）ab2.62400.0039360.9960711587.4616.95bc1.0530.06980.0399760.960811155

20、3.096.66cd9.40500.0141080.9859901511.5657.86de2.2790.11340.0658150.9363031452.6013.48ef1.59600.0023940.9976081403.649.12 L=（16.95+6.66+57.86+13.48+9.12）*2=208.14mm （設(shè)計(jì)值為198.6mm） 預(yù)張拉伸長量計(jì)算：N6伸長量張拉力為：930×9×140=1171.8KN線段L（米）（rad）kx+e-(kx+)終點(diǎn)力（KN）L（mm）ab2.62400.0039360.9960711099.3211.74bc1.05

21、30.06980.0399760.9608111075.524.61cd4.28300.0064230.9935961050.7918.32de2.2790.11340.0658150.9363031013.699.41ef6.68600.0100290.990021975.8026.55 L=（11.74+4.61+18.32+9.41+26.55）*2=141.26mmN2a伸長量張拉力為：930×9×140=1171.8KN線段L（米）（rad）kx+e-(kx+)終點(diǎn)力（KN）L（mm）ab3.98700.0059810.9940361098.2017.82bc1.

22、0460.06980.0399660.9608211073.334.57cd11.70400.0175560.9825971042.8549.68 L=（17.82+4.57+49.68）*2=144.14mm N1b伸長量張拉力為：930×9×140=1171.8KN線段L（米）（rad）kx+e-(kx+)終點(diǎn)力（KN）L（mm）ab3.86500.0057980.9942181098.3017.28bc1.0460.06980.0399660.9608211073.534.57cd11.70400.0175560.9825971043.0449.69L=（17.28+

23、4.57+49.69）*2=143.08mm 初張拉伸長量計(jì)算：N2a伸長量張拉力為：930×9×140=1171.8KN線段L（米）（rad）kx+e-(kx+)終點(diǎn)力（KN）L（mm）ab3.98700.0059810.9940361098.2017.83bc1.0460.06980.0399660.9608211073.334.57cd11.70400.0175560.9825971042.8549.67 L=（17.83+4.57+49.67）*2=144.13mmN3伸長量張拉力為：930×9×140=1171.8KN線段L（米）（rad）kx+e-(kx+)終點(diǎn)力（KN）L（mm）ab2.51300.0037690.9962371099.4211.25bc2.1030.13960.0799490.9231631054.639.03cd0.79500.0011920.9988081012.433.27de2.2790.11340.0658150.936303979.249.09ef9.23200.0138480.986247940.8435.35L=（11.25+9.03+3.27+9.09+35.35）*2=135.98mm N7伸長量張拉力為：930×