大跨径预应力混凝土梁桥孔道摩阻试验研究
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摘要
为更精确地进行施工监控,结合某三跨连续梁桥,通过现场试验得出实际孔道摩阻系数。对实测得到的短、长预应力束的摩阻系数和管道偏差系数对比分析,并根据实测数据修正有限元模型,对比分析修正后支座截面顶板的应力理论计算值与现场实测值。试验得出不同长度预应力束的摩擦系数μ分别为0.254和0.282,偏差系数k分别为0.002 0和0.001 7。结果表明,实际施工过程中的摩阻系数大于规范上限值1.6%~33.3%,不同长度的预应力束的摩阻系数存在较大离散性,随着预应力束的增长,曲线处由于法向挤压力导致的摩阻损失占整体预应力摩阻损失的比重增加,长束预应力束相比较短束μ值增加了11%,k值减小了15%。支座截面顶板应力实测值与理论计算值变化趋势一致,采用实测值修正后误差减小,两次修正误差分别减少了10%和9%。
The friction in a post-tensioning system has a significant effect on the distribution of prestressing force in a prestressed concrete structure. One of the major causes leading to the deteriorations like the deflect ion and cracking of current long span prestressed concrete beam bridge was underestimating the prestressing loss. The failure or destruction of bridge structure was caused by excessive prestress loss. For more precise construction monitoring,combined with a three span continuous beam bridge,the actual frictional coefficient of the channel was obtained through field test. This paper made a contrast between friction coefficient of prestressing tendon at different lengths and pipeline deviation coefficient that measured,then modified finite element model with measured data. Finally,the comparison between modified theoretical calculation value and field measured value of support section roof stress was analyzed. The friction coefficients of prestressing tendons with different lengths were 0. 254 and 0. 282,respectively,and the deviation coefficient K were 0. 002 0 and 0. 001 7,respectively. The results showed that the friction coefficient of the actual construction process was 1. 6%-33. 3% higher than the upper limit value of the norm,and friction coefficients of prestressing tendon at different lengths have obvious discreteness. Moreover,friction losses caused by normal extrusion force at the curve section increased with the increase in prestressing tendon length. Compared with the short prestressed tendons,μ value of long prestressed tendons increased by 11%,and k value reduced by 15%. The changing trend of theoretical calculation values and measured values of roof stress was consistent. Errors decreased by 10% and 9% after parameter correcting based on measured values.
The friction in a post-tensioning system has a significant effect on the distribution of prestressing force in a prestressed concrete structure. One of the major causes leading to the deteriorations like the deflect ion and cracking of current long span prestressed concrete beam bridge was underestimating the prestressing loss. The failure or destruction of bridge structure was caused by excessive prestress loss. For more precise construction monitoring,combined with a three span continuous beam bridge,the actual frictional coefficient of the channel was obtained through field test. This paper made a contrast between friction coefficient of prestressing tendon at different lengths and pipeline deviation coefficient that measured,then modified finite element model with measured data. Finally,the comparison between modified theoretical calculation value and field measured value of support section roof stress was analyzed. The friction coefficients of prestressing tendons with different lengths were 0. 254 and 0. 282,respectively,and the deviation coefficient K were 0. 002 0 and 0. 001 7,respectively. The results showed that the friction coefficient of the actual construction process was 1. 6%-33. 3% higher than the upper limit value of the norm,and friction coefficients of prestressing tendon at different lengths have obvious discreteness. Moreover,friction losses caused by normal extrusion force at the curve section increased with the increase in prestressing tendon length. Compared with the short prestressed tendons,μ value of long prestressed tendons increased by 11%,and k value reduced by 15%. The changing trend of theoretical calculation values and measured values of roof stress was consistent. Errors decreased by 10% and 9% after parameter correcting based on measured values.
引文
[1]郭振武,彭楠楠.预应力混凝土箱梁孔道摩阻损失测试[J].公路,2010(12):60-67.GUO Z W,PENG N N.Test of prestressed concrete box girder channel friction loss[J].Highway,2010(12):60-67.
[2]吉伯海,傅中秋.近年国内桥梁倒塌事故原因分析[J].土木工程学报,2010(S1):495-498.JI B H,FU Z Q.Analysis of Chinese bridge collapse accident causes in recent years[J].China Civil Engineering Journal,2010(S1):495-498.
[3]徐洪涛,郭国忠,蒲焕玲,等.我国近年来桥梁事故发生的原因与教训[J].中国安全科学学报,2007,17(11):90-95.XU H T,GUO G Z,PU H L,et al.Causes and lessons of bridge accidents in China in recent years[J].China Safety Science Journal,2007,17(11):90-95.
[4]李准华,刘钊.大跨度预应力混凝土梁桥预应力损失及敏感性分析[J].世界桥梁,2009(1):36-39.LI Z H,LIU Z.Analysis of prestressing loss and sensitivity of long span prestressed concrete beam bridge[J].World Bridges,2009(1):36-39.
[5]BARR P J,KUKAY B M,HALLING M W.Comparison of prestress losses for a prestress concrete bridge made with high-performance concrete[J].Journal of Bridge Engineering,2008,13(5):468-475.
[6]王涛,钟穗东,张汉平.预应力孔道摩阻系数测试与分析[J].公路,2010(5):35-38.WANG T,ZHONG S D,ZHANG H P.Test and analysis of pres- tressed duct friction factor[J].Highway,2010(5):35-38.
[7]GARBER D B,GALLARDO J M,DESCHENES D J,et al.Experimental investigation of prestress losses in full-scale bridge girders[J].ACI Structural Journal,2015,112(5):553.
[8]CARO L A,MARTI-BARGAS J R,SERNA P.Prestress losses evaluation in prestressed concrete prismatic specimens[J].Engineering Structures,2013,48:704-715.
[9]LUNDQVIST P,NILSSON L O.Evaluation of prestress losses in nuclear reactor containments[J].Nuclear Engineering and Design,2011,241(1):168-176.
[10]王强,何惟煌,林志春,等.后张预应力混凝土梁管道摩阻参数识别与分析[J].公路交通科技,2007,24(1):65-68.WANG Q,HE W H,LIN Z C,et al.Parameter identification and analysis of tube friction resistance loss in the post-tensioned pre-stressed concrete girders[J].Journal of Highway and Transportation Research and Development,2007,24(1):65-68.
[11]刘喜元,陈玉骥,罗旗帜,等.惠州下角东江大桥钢绞线孔道摩阻预应力损失的试验研究[J].中外公路,2008,28(2):133-136.
[12]张开银,顾津申,张军辉,等.弯曲孔道摩阻预应力损失试验研究[J].武汉理工大学学报(交通科学与工程版),2009,33(2):306-309.ZHANG K Y,GU J S,ZHANG J H,et al.Experimental study about prestressing loss of strand caused by frictional resistance in curving hole[J].Journal of Wuhan University of Technology(Transportation Science&Engineering),2009,33(2):306-309.
[13]张开银,郭志伟,顾津申.PC弯曲孔道摩阻预应力损失试验与分析[J].中外公路,2010,30(4):145-149.ZHANG K Y,GUO Z W,GU J S.Test and analysis of PC curved hole friction loss of prestress[J].Journal of China&Foreign Highway,2010,30(4):145-149.
[14]肖财,张开银,黎晨.PC弯曲孔道摩阻损失中接触应力分布试验[J].武汉理工大学学报(交通科学与工程版),2015,39(2):367-370.XIAO C,ZHANG K Y,LI C.Test of contact stress distribution in curving hole friction loss[J].Journal of Wuhan University of Technology(Transportation Science&Engineering),2015,39(2):367-370.
[15]张文学,谢全懿,李学斌,等.高速铁路桥梁预应力孔道摩阻损失系数测试误差敏感性分析[J].中国铁道科学,2015,36(6):31-36.ZHANG W X,XIE Q Y,LI X B,et al.Analysis on test error sensitivity of prestressed duct friction loss coefficient of high speed railway bridge[J].China Railway Science,2015,36(6):31-36.
[16]CHO K,KIM S T,PARK S Y,et al.Computation of the strand resistance using the core wire strain measurement[J].Engineering,2013,5(11):850-855.
[17]JEON S,PARK S,KIM S T,et al.Estimation of friction coefficient using smart strand[J].International Journal of Concrete Structures and Materials,2015,9(3):369-379.
[2]吉伯海,傅中秋.近年国内桥梁倒塌事故原因分析[J].土木工程学报,2010(S1):495-498.JI B H,FU Z Q.Analysis of Chinese bridge collapse accident causes in recent years[J].China Civil Engineering Journal,2010(S1):495-498.
[3]徐洪涛,郭国忠,蒲焕玲,等.我国近年来桥梁事故发生的原因与教训[J].中国安全科学学报,2007,17(11):90-95.XU H T,GUO G Z,PU H L,et al.Causes and lessons of bridge accidents in China in recent years[J].China Safety Science Journal,2007,17(11):90-95.
[4]李准华,刘钊.大跨度预应力混凝土梁桥预应力损失及敏感性分析[J].世界桥梁,2009(1):36-39.LI Z H,LIU Z.Analysis of prestressing loss and sensitivity of long span prestressed concrete beam bridge[J].World Bridges,2009(1):36-39.
[5]BARR P J,KUKAY B M,HALLING M W.Comparison of prestress losses for a prestress concrete bridge made with high-performance concrete[J].Journal of Bridge Engineering,2008,13(5):468-475.
[6]王涛,钟穗东,张汉平.预应力孔道摩阻系数测试与分析[J].公路,2010(5):35-38.WANG T,ZHONG S D,ZHANG H P.Test and analysis of pres- tressed duct friction factor[J].Highway,2010(5):35-38.
[7]GARBER D B,GALLARDO J M,DESCHENES D J,et al.Experimental investigation of prestress losses in full-scale bridge girders[J].ACI Structural Journal,2015,112(5):553.
[8]CARO L A,MARTI-BARGAS J R,SERNA P.Prestress losses evaluation in prestressed concrete prismatic specimens[J].Engineering Structures,2013,48:704-715.
[9]LUNDQVIST P,NILSSON L O.Evaluation of prestress losses in nuclear reactor containments[J].Nuclear Engineering and Design,2011,241(1):168-176.
[10]王强,何惟煌,林志春,等.后张预应力混凝土梁管道摩阻参数识别与分析[J].公路交通科技,2007,24(1):65-68.WANG Q,HE W H,LIN Z C,et al.Parameter identification and analysis of tube friction resistance loss in the post-tensioned pre-stressed concrete girders[J].Journal of Highway and Transportation Research and Development,2007,24(1):65-68.
[11]刘喜元,陈玉骥,罗旗帜,等.惠州下角东江大桥钢绞线孔道摩阻预应力损失的试验研究[J].中外公路,2008,28(2):133-136.
[12]张开银,顾津申,张军辉,等.弯曲孔道摩阻预应力损失试验研究[J].武汉理工大学学报(交通科学与工程版),2009,33(2):306-309.ZHANG K Y,GU J S,ZHANG J H,et al.Experimental study about prestressing loss of strand caused by frictional resistance in curving hole[J].Journal of Wuhan University of Technology(Transportation Science&Engineering),2009,33(2):306-309.
[13]张开银,郭志伟,顾津申.PC弯曲孔道摩阻预应力损失试验与分析[J].中外公路,2010,30(4):145-149.ZHANG K Y,GUO Z W,GU J S.Test and analysis of PC curved hole friction loss of prestress[J].Journal of China&Foreign Highway,2010,30(4):145-149.
[14]肖财,张开银,黎晨.PC弯曲孔道摩阻损失中接触应力分布试验[J].武汉理工大学学报(交通科学与工程版),2015,39(2):367-370.XIAO C,ZHANG K Y,LI C.Test of contact stress distribution in curving hole friction loss[J].Journal of Wuhan University of Technology(Transportation Science&Engineering),2015,39(2):367-370.
[15]张文学,谢全懿,李学斌,等.高速铁路桥梁预应力孔道摩阻损失系数测试误差敏感性分析[J].中国铁道科学,2015,36(6):31-36.ZHANG W X,XIE Q Y,LI X B,et al.Analysis on test error sensitivity of prestressed duct friction loss coefficient of high speed railway bridge[J].China Railway Science,2015,36(6):31-36.
[16]CHO K,KIM S T,PARK S Y,et al.Computation of the strand resistance using the core wire strain measurement[J].Engineering,2013,5(11):850-855.
[17]JEON S,PARK S,KIM S T,et al.Estimation of friction coefficient using smart strand[J].International Journal of Concrete Structures and Materials,2015,9(3):369-379.