江苏丹阳运河大桥吊杆索力监测及剖析.docVIP

江苏丹阳运河大桥吊杆索力监测及剖析 　　摘要：近年来，不断有系杆拱桥吊杆破损及更换的工程案例出现。因此，对系杆拱桥吊杆在施工阶段与活载作用下的受力状况进行深入研究有很有必要。江苏丹阳运河大桥是一座下承式系杆拱桥，其吊杆由拉索与钢护筒两部分组成。拉索为集束高强钢丝，与钢护筒之间无填充物。施工中，吊杆拉索安装定位后，吊杆钢护筒与拱肋钢管外壁及系杆骨架焊接为一体。这样，施工时，张拉拉索时也相应地会对钢护筒产生压应力。本文对丹阳运河大桥各个施工阶段及成桥状态静载试验时的索力进行了监测，并利用有限元方法对相应阶段进行数值计算，研究了本桥在各个受力阶段吊杆应力变化及吊杆拉索与钢护筒内力分配的关系。 　　关键词：系杆拱桥；吊杆；钢护筒；索力监测；静载试验 　　 　　MEASUREMENT AND ANALYSIS OF STRESS IN THE SUSPENDER FOR DANYANG CANAL BRIDGE IN JIANGSU PROVINCE 　　 　　XIAO Liang 　　（1.Nanning Survay and Design Institute CO., LTD. of China Railway Siyuan Group, Nanning, Guangxi 530003, China； 　　2.School of Civil Engineering, Beijing Jiaotong University, Beijing 100044, China） 　　 　　Abstract: In recent years, there are some collapse cases because of the suspender failure in the tied-arch bridge. So it’s quite necessary to do some research concerning the stress change in suspenders during the construction stage as well as serviceability state. Danyang Canal Bridge in Jiangsu province is a tied arch bridge, its suspender consists of two parts, one is the stay cable, and the other is the steel tube which is used for protecting the stay cable. The stay cable is made from bunched steel wires. There isn’t any filling material between the steel tube and the stay cable. In this bridge, the steel tube is not only for protection of the stay cable, but also acts as a part of the suspender, which carries some forces during the construction stage as well as serviceability state. In this paper, the stresses of the stay cable and the steel tube are measured and numerically analysed at different construction stages and under loading test when the bridge construction is finished. 　　Keywords: tied-arch Bridge; suspender; steel protection tube; stress monitor; loading test 　　 　　1前言 　　系杆拱桥是一种无推力的梁拱组合体系桥，将主要承受压力的拱肋和主要承受弯矩的行车道梁组合起来共同承受荷载，充分发挥了梁受弯、拱受压的结构性能和组合作用。系杆拱桥拱肋产生的水平推力由系杆承担，所以外部是静定结构，但在内部却是高次超静定结构，任一吊杆内力的改变对全桥各构件受力状态都有一定影响[1,2,3]。 　　江苏丹阳运河大桥为新建桥梁，位于江苏241省道丹阳大泊至珥陵段，跨越京杭大运河，主桥为1×100m钢管砼下承式系杆拱，引桥采用20m先张法预应力砼空心板梁，为