刚性吊杆拱加固梁桥结构参数分析  

Parametric Analysis of Using Arch with Rigid Hangers to Strengthen Beam Bridge

作　　者：陈伏立 

机构地区：[1]福州市规划勘测设计研究总院,福建福州350108

出　　处：《世界桥梁》2017年第6期82-86,共5页World Bridges

摘　　要：为研究刚性吊杆系杆拱加固梁桥结构参数对桥梁受力性能的影响,指导加固设计优化,以既有城市人行过街天桥主跨钢梁拆墩提载加固工程为背景,运用MIDAS Civil软件,采用累加模型按照实际加固步骤建立加固后桥梁空间有限元模型,计算旧桥钢梁损伤度、拱肋、吊杆、内部约束条件等参数变化下,加固后桥梁结构的最大主应力、位移和自振频率等指标的变化规律,并进行对比分析。结果表明:旧桥钢梁的损伤降低了结构整体刚度;拱轴线形以二次抛物线为最优,1/5是较优矢跨比,拱肋需要具备一定的刚度才能满足受力要求;吊杆刚度及其框架作用对结构整体刚度具有较大影响,对钢梁和拱肋的受力影响较小;拱脚铰接对加固后结构的受力不利。To study the influence of structural parameters of using tied arch with rigid hangers to strengthen beam bridge on the load bearing capacity of the bridge and guide the design optimiza-tion, the strengthening project of an urban pedestrian bridge, including the demolition of the piers and improvement of load bearing capacity, was taken as the study background. The MIDAS Civil software was used to establish the special finite element model of the bridge using the accumulative model following the actual strengthening process. A series of parameters of the old and new bridg-es were calculated and contrastively analyzed, including the damage degree of the steel beam, arch rib, hangers and internal restraint condition as well as the maximum tensile strength, displacement and natural vibration frequencies of the bridge after strengthening. The results show that the dam-ages of the steel beam of the old bridge have degraded the overall stiffness of the structure. The parabolic curve is considered the ideal geometry of the arch axis, and 1/5 the ideal rise-to -span ratio. The arch ribs should have a certain degree of stiffness to meet the load-bearing demands of the bridge. The stiffness of the hangers and the frame effect have great influence on the overall stiffness of the structure, but minimal influence on the load bearing capacity of the steel beam and arch ribs. The hinged connection at the arch springs is not favorable to the load bearing behavior of the structure.

关 键 词：梁桥 刚性吊杆 系杆换 结构参数 主应力 位移 自振频率 桥梁加固 有限元法 

分 类 号：U445.72[建筑科学—桥梁与隧道工程]