钢管拱混凝土顶升法灌注施工技术

摘要

The large-span continuous beam-arch combination is commonly used in the highway and railway, and the concrete steel pipe arch construction is critical in such structure construction. The site construction technology control has significant impact on the quality of concrete pipe arch and the structural safety. In the arch concrete construction, it generally uses the "Pumping boost injection" process, dense concrete free from vibration and if forms load-bearing structure with the outer hoop steel. Taking the continuous beam-arch steel concrete arch construction of Xi’an-Baoji Passenger Dedicated Line Western Xianyang Interchange Bridge (64 +136 +64)m for example, this article describes the concrete process of concrete pipe arch perfusion with jacking method, concrete mix selection, pumping process, construction organization, construction control points, emergency measures, to provide experience and technical reference for the construction of the same structure.%大跨度连续梁-拱组合形式在公铁路中普遍采用，而此类结构施工中钢管拱肋混凝土施工非常关键，现场的施工工艺控制对钢管混凝土拱的质量和结构安全影响重大。拱内混凝土施工一般采用“泵送顶升压注”工艺，混凝土免振自密，与外箍钢管形成承力结构。本文以西宝客专咸阳西立交特大桥（64+136+64）m连续梁-拱钢管混凝土灌注施工为例，介绍了顶升法灌注钢管拱混凝土的工艺流程、混凝土配合比选择、泵送工艺、施工组织、施工控制要点、应急处理措施等内容，为同类型结构的施工提供经验和技术借鉴。