多塔悬索桥中塔鞍座水平摩擦板抗滑方案试验研究
|
摘要
为解决多塔悬索桥主缆与中塔鞍座间的抗滑问题,提出在鞍座内增设水平摩擦板的抗滑设计方案,通过模型试验研究鞍座设置水平摩擦板后主缆索股的滑移特性,并提出主缆名义摩擦系数的计算方法,以温州瓯江北口大桥[(230+2×800+348)m三塔悬索桥]为对象进行抗滑方案研究。结果表明:加载初期,顶推所产生的不平衡力在索股间基本平均分配;随着加载继续,各索股以水平摩擦板为界呈现明显的分层滑移现象;索股与鞍座相对位移随索力差变化过程可分为线性变化、局部蠕动和滑移3个阶段;提出的主缆名义摩擦系数计算方法可用于中塔鞍座内设有水平摩擦板时主缆的抗滑能力计算;对于温州瓯江北口大桥,采用2块水平摩擦板分别设置于距顶部约1/4及1/2处是合理可行的抗滑方案。
To provide solution to the anti-slip between the main cable and middle tower saddle of the multi-tower suspension bridge,the anti-slip scheme of adding one more horizontal friction plate to the saddle was proposed.The characteristics of the slip of the main cable strands in the saddle after the friction plate was added were investigated through the model tests and the calculation method for the nominal friction coefficients of the main cable was accordingly given.By way of example the Oujiang River North Estuary Bridge in Wenzhou [a three-tower suspension bridge with span arrangement(230+2×800+348)m],the anti-slip scheme was studied.The results yield that at the early stage of loading,the unbalanced forces produced by the pushing of the saddle basically equally distribute among the cable strands.With the continuous loading,the strands exhibit the phenomenon of the notable slip in layers,referring to the horizontal friction plates as the boundary.The relative displacement between the strands and saddle changing with the cable force differences can be divided into the 3 stages of the linear changing stage,local creep stage and slip stage.The given calculation method for the nominal friction coefficients can be used for calculation of the anti-slip capacity of the main cable when the friction plate is added to the middle tower saddle.For the Oujiang River North Estuary Bridge,the reasonable and feasible anti-slip scheme is that the 2 horizontal friction plates should be arranged respectively at about 1/4 and 1/2 locations to the top of the tower.
To provide solution to the anti-slip between the main cable and middle tower saddle of the multi-tower suspension bridge,the anti-slip scheme of adding one more horizontal friction plate to the saddle was proposed.The characteristics of the slip of the main cable strands in the saddle after the friction plate was added were investigated through the model tests and the calculation method for the nominal friction coefficients of the main cable was accordingly given.By way of example the Oujiang River North Estuary Bridge in Wenzhou [a three-tower suspension bridge with span arrangement(230+2×800+348)m],the anti-slip scheme was studied.The results yield that at the early stage of loading,the unbalanced forces produced by the pushing of the saddle basically equally distribute among the cable strands.With the continuous loading,the strands exhibit the phenomenon of the notable slip in layers,referring to the horizontal friction plates as the boundary.The relative displacement between the strands and saddle changing with the cable force differences can be divided into the 3 stages of the linear changing stage,local creep stage and slip stage.The given calculation method for the nominal friction coefficients can be used for calculation of the anti-slip capacity of the main cable when the friction plate is added to the middle tower saddle.For the Oujiang River North Estuary Bridge,the reasonable and feasible anti-slip scheme is that the 2 horizontal friction plates should be arranged respectively at about 1/4 and 1/2 locations to the top of the tower.
引文
[1]Thai H T,Choi D H.Advanced Analysis of MultiSpan Suspension Bridges[J].Journal of Constructional Steel Research,2013,90:29-41.
[2]Zhang L W,Xiao R C,Sun B,et al.Study on Economic Performances of Multi-Span Suspension Bridges,Part 1:Simple Estimation Formulas[J].Structural Engineering and Mechanics,2013,47(2):265-286.
[3]沈锐利,张兴标,彭丹.多塔悬索桥结构变形的实用计算方法[J].中国公路学报,2016,29(6):207-213.(SHEN Rui-li,ZHANG Xing-biao,PENG Dan.Practical Calculation Method for Structural Deformation of Multi-Span Suspension Bridge[J].China Journal of Highway and Transport,2016,29(6):207-213.in Chinese)
[4]Ruan X,Zhou J Y,Caprani C C.Safety Assessment of the Antisliding between the Main Cable and Middle Saddle of a Three-Pylon Suspension Bridge Considering Traffic Load Modeling[J].Journal of Bridge Engineering,2016,21(10):24046069-1-04016069-10.
[5]Zhang Q,Cheng Z,Cui C,et al.Analytical Model for Frictional Resistance between Cable and Saddle of Suspension Bridge Equipped with Vertical Friction Plates[J].Journal of Bridge Engineering,2016,22(1):04016103-1-04016103-12.
[6]Gimsing N J,Georgakis C T.Cable Supported Bridges:Concept and Design,Third Edition[M].New York:A John Wiley&Sons,Ltd.,2012.
[7]沈锐利,王路,王昌将,等.悬索桥主缆与索鞍间侧向力分布模式的模型试验研究[J].土木工程学报,2017,50(10):75-81.(SHEN Rui-li,WANG Lu,WANG Chang-jinag,et al.Experimental Study on Distribution Pattern of Lateral Force between Main Cable and Cable Saddle for Suspension Bridge[J].China Civil Engineering Journal,2017,50(10):75-81.in Chinese)
[8]Hasegawa K,Kojima H,Sasaki M,et al.Frictional Resistance between Cable and Saddle Equipped with Friction Plate[J].Journal of Structural Engineering,1995,121(1):1-14.
[9]Zhang X,Xu Y,Zhan S,et al.Simulation of Support Settlement and Cable Slippage by Using a Long-Span Suspension Bridge Testbed[J].Structure and Infrastructure Engineering,2017,13(3):401-415.
[10]JTG/T D65-05-2015,公路悬索桥设计规范[S].(JTG/T D65-05-2015,Specifications for Design of Highway Suspension Bridge[S].)
[2]Zhang L W,Xiao R C,Sun B,et al.Study on Economic Performances of Multi-Span Suspension Bridges,Part 1:Simple Estimation Formulas[J].Structural Engineering and Mechanics,2013,47(2):265-286.
[3]沈锐利,张兴标,彭丹.多塔悬索桥结构变形的实用计算方法[J].中国公路学报,2016,29(6):207-213.(SHEN Rui-li,ZHANG Xing-biao,PENG Dan.Practical Calculation Method for Structural Deformation of Multi-Span Suspension Bridge[J].China Journal of Highway and Transport,2016,29(6):207-213.in Chinese)
[4]Ruan X,Zhou J Y,Caprani C C.Safety Assessment of the Antisliding between the Main Cable and Middle Saddle of a Three-Pylon Suspension Bridge Considering Traffic Load Modeling[J].Journal of Bridge Engineering,2016,21(10):24046069-1-04016069-10.
[5]Zhang Q,Cheng Z,Cui C,et al.Analytical Model for Frictional Resistance between Cable and Saddle of Suspension Bridge Equipped with Vertical Friction Plates[J].Journal of Bridge Engineering,2016,22(1):04016103-1-04016103-12.
[6]Gimsing N J,Georgakis C T.Cable Supported Bridges:Concept and Design,Third Edition[M].New York:A John Wiley&Sons,Ltd.,2012.
[7]沈锐利,王路,王昌将,等.悬索桥主缆与索鞍间侧向力分布模式的模型试验研究[J].土木工程学报,2017,50(10):75-81.(SHEN Rui-li,WANG Lu,WANG Chang-jinag,et al.Experimental Study on Distribution Pattern of Lateral Force between Main Cable and Cable Saddle for Suspension Bridge[J].China Civil Engineering Journal,2017,50(10):75-81.in Chinese)
[8]Hasegawa K,Kojima H,Sasaki M,et al.Frictional Resistance between Cable and Saddle Equipped with Friction Plate[J].Journal of Structural Engineering,1995,121(1):1-14.
[9]Zhang X,Xu Y,Zhan S,et al.Simulation of Support Settlement and Cable Slippage by Using a Long-Span Suspension Bridge Testbed[J].Structure and Infrastructure Engineering,2017,13(3):401-415.
[10]JTG/T D65-05-2015,公路悬索桥设计规范[S].(JTG/T D65-05-2015,Specifications for Design of Highway Suspension Bridge[S].)