连续梁0号块缺陷处理精细有限元分析

Precise Finite Element Analysis on Defect Treatment for Hammer Head Block of Continuous Girder

一客运专线有砟轨道挂篮悬浇连续梁,主墩0号块混凝土浇筑完成后出现多处浮浆缺陷。本文研究对0号块混凝土缺陷加以修复的可行性,采用Midas软件建立包含0号块、1号块的局部空间实体有限元模型和全桥梁单元模型,模拟缺陷及修补过程、缺陷凿除及重新施工对0号块及全桥应力和变形的影响。计算结果表明:2个主墩0号块龄期差对全桥的应力和变形均影响较小;修补过程中及修补后0号块应力和变形均满足相关规范要求;选用不同等级补浇筑混凝土对0号块的应力和变形影响不大,但选用C55混凝土箱梁应力相对较小。0号块缺陷修复处理方案可行。

A ballasted track continuous girder bridge was constructed with cantilever erection method in a passenger dedicated railway. Concrete laitance was found on several places after concrete casting of the hammer head block（ No. 0 block）. The practicability of defect fixing was studied in this paper. The whole bridge model and local No. 0and No. 1 block models were created by finite element analysis software to simulate the defect treatment and construction process. The effects of treatment construction including stress and deflection of the bridge were analyzed. The calculation results show that the stress and deformation of the bridge almost keep unchanged with different concrete age of two No. 0 blocks. The stress and deformation of the No. 0 block satisfy requirements of the design code during and after repairing process,being insensitive to the repairing concrete grade. Relatively smaller stress follows with C55 repairing concrete. The defect fixing plan is feasible.