大跨度铁路连续梁-拱组合桥梁施工技术及质量控制

Construction technology and quality control of large span continuous beam arch composite bridge in the railway

以新建徐盐铁路为工程背景,在前期对某连续梁-拱吊杆预应力张拉监测控制和预应力压浆孔道密实度检测等基础上,对新建徐盐铁路200 m连续梁-拱组合桥混凝土、梁体预应力、压浆以及吊杆预应力等施工关键技术进行研究,对施工过程中存在的质量风险进行总结,如拱脚混凝土质量差、竖向精轧螺纹钢预应力损失、预应力孔道堵塞、压浆质量不密实、吊杆张拉不同步、锚固损失和二期恒载施加后索力调整等,分析其发生的原因以及可能产生的后果,并依据质量风险来确定控制要点,最后通过控制混凝土质量、减小预应力损失以及优化张拉工序等措施来降低质量风险。

Based on monitoring and control of prestress tension and density test of grouting duct of a continuous beam arch hanger,the key technique of construction of 200 m continuous beam arch composite bridge on newly-built Xu-Yan railway in the early stage,such as concrete,beam prestress,grouting as well as suspender prestress,was studied in this paper.The quality risk existing in the construction process was summarized,such as poor quality of arch foot concrete,prestress loss of vertical finishing steel,clogging of prestressed duct,compaction grouting quality,boom tension out of sync,anchorage loss,and adjustment of cable force after application of two stage load.The causes and possible consequences were analyzed,and the control points were determined according to the quality risk.Finally,the quality risk was reduced by controlling the quality of concrete,reducing the loss of prestress and optimizing the tensioning process.