组合钢模板全圆断面隧洞衬砌施工技术

Construction technology of tunnel lining with full circular section of composite steel formwork

暗涵曲线段转弯半径较小,不适用于台车模板进行二衬浇筑,须采用组合钢模板全圆断面一次浇筑成型。组合钢模板选用直线模板+短曲线模板的施工方案。为保证模板稳定,采取环向工字钢梁+纵向工字钢梁+竖向钢管支撑的加固体系,其中钢管通过模板顶部窗口支撑到一衬表面起到抗浮作用,浇筑过程中需要加强抗浮监测。通过对组合钢模板精确的设计、施工,能够实现暗涵曲线段衬砌要求,确保暗涵混凝土施工质量。

The turning radius of hidden culvert curve section is small.It is not suitable for the secondary lining casting of trolley formwork.The full circular section of composite steel formwork should be cast and formed at one time.The construction scheme of straight line formwork+short curve formwork is adopted for composite steel formwork.The reinforcement system of circular I-shaped steel beams+longitudinal I-shaped steel beams+vertical steel pipe support is adopted in order to ensure the stability of the formwork,wherein the steel pipe supports the primary lining surface through the top window of the formwork,thereby playing an anti-floating role.Anti-floating monitoring should be strengthened during the casting process.The lining requirements of culvert curve section can be realized and the construction quality of culvert concrete can be ensured through the accurate design and construction of the composite steel formwork.