大坡度宽断面桥梁同步顶升全过程有限元分析

桥梁顶升工程是指通过使用液压或机械设备将桥梁升到一定高度,以便进行维修、加固或更换桥梁部件的工程。以哈尔滨东三环某既有桥梁为例,应用Midas-Civil有限元仿真模拟软件,在施工前,通过对桥梁顶升全过程的仿真模拟分析,提前对危险应力进行干预。该项目共6个工况,分析表明,在前3个工况的分析中,应力均未超限,但在工况4下箱梁底板的拉应力达到σ_(max)=10.6 MPa>[σ]=3.0 MPa,超过相关规范的规定。为此,在保证设计意图的前提下,对设计给定的某几个点位的顶升高度进行微调,调整后的拉应力降至σ_(max)=2.9 MPa<[σ]=3.0 MPa,满足规范的要求,且在随后2个工况下的施工中,均未再出现超出相关规范要求的应力值。

Bridge jacking project refers to the project of using hydraulic or mechanical equipment to raise the bridge to a certain height for maintenance,reinforcement or replacement of bridge parts.Taking an existing bridge in the East Third Ring Road of Harbin as an example,this paper applies the finite element simulation software Midas-Civil to intervene the dangerous stress in advance through the simulation analysis of the whole process of bridge jacking before construction.The project has six working conditions,and the analysis shows that in the first three working conditions,the stress does not exceed the limit,but under condition 4,the tensile stress of the bottom plate of the box girder reaches σ_(max)=10.6 MPa>[σ]=3.0 MPa,which exceeds the provisions of the relevant specifications.For this reason,on the premise of ensuring the design intention,the jacking height of some points given by the design is fine-tuned,and the adjusted tensile stress is reduced to σ_(max)=2.9 MPa<[σ]=3.0 MPa,which meets the requirements of the code,and the stress value that exceeds the requirements of the relevant code does not appear in the construction under the following two working conditions.