连续钢箱梁桥顶升改造方案比选及关键技术  

Scheme Comparison and Selection for Jacking-Up of Continuous Steel Box Beam Bridge and Key Techniques Used

作　　者：刘欣益 杨子江[1] 冯明扬 黄俊豪[1] 伍明强 

机构地区：[1]兰州交通大学土木工程学院,甘肃兰州730070

出　　处：《世界桥梁》2016年第1期87-91,共5页World Bridges

基　　金：国家自然科学基金项目(51368032)

摘　　要：厦门仙岳路跨台湾街路口连续钢箱梁桥(编号L3)为(36+45+36)m竖向凸曲线下坡桥梁,根据高架桥提升改造的线形要求,需将L3联桥顶升调整为凹曲线上坡桥。经多方案优化确定采用先整体顶升后将其切割为7段进行调坡改造的方案。采用有限元软件建立L3联桥整体及局部模型,通过顶升改造施工仿真优化,设定了现场实时监控的位移和应力偏差预警值,确定每次顶升行程100mm;对顶点位置钢箱梁腹板增设加劲肋进行加固,避免腹板局部失稳;设置独立的纵向限位装置,使L3、L4两联桥梁的纵向伸长互不干扰;按精确理论计算值给千斤顶和分配梁中心设置预偏心,解决梁体旋转伸长问题;加工可微形转动的千斤顶支撑垫板和不同倾角的楔形钢板垫块,保证分配梁底面和千斤顶顶面在顶升过程始终保持密贴。The continuous steel box beam bridge which is numbered L3 crossing the intersection of Xianyue Road and Taiwan Street in Xiamen is a downhill bridge with vertical convex curvature and with span arrangement of（36＋42＋36）m.According to the requirements for geometrical shape presented for jacking-up rehabilitation of viaduct,the bridge in the L3 unit has to be adjusted to become an uphill bridge with concave curvature.By scheme comparison and optimization,it was determined to jack up the overall bridge first and then divide the bridge into seven sections to carry out gradient adjustment.The finite element software was used to establish the overall and local models of the bridge of L3 unit,by numerical simulation and optimization of the jacking-up rehabilitation,the alarming values of displacement and stress deviation for site real-time monitoring were set.The determined jacking-up length for each operation is 100 mm.At the jacking points,stiffening ribs were added to the webs of the steel box beam to avoid the occurrence of local instability of the webs.Independent longitudinal constraints were installed,to ensure that the longitudinal expansion of the L3 and L4continuous units of the bridge does not disturb each other.In accordance with the accurate theoretical values,the pre-eccentricity for the jacks and distribution beam were set,to solve the problem of beam rotation and expansion.The supporting pad for jacks which can slightly rotate and the wedge-shaped steel pads with different angles were prepared,so as to ensure the underside of the distribution beam and the top surface of the jacks can always be closely touched during the jacking-up process.

关 键 词：连续梁桥 钢箱梁 桥梁顶升 切割 线形调整 方案比选 有限元法 

分 类 号：U445.4[建筑科学—桥梁与隧道工程]