从古运河枢纽谈大型输水涵洞混凝土施工裂缝防止

大型输水涵洞属大体积混凝土施工，由于设计、施工或地质等方面原因，尤其是基础约束力、温度应力以及其他外部应力等的影响，极易造成混凝土裂缝，给工程管理、运用带来隐患。南水北调中线干线工程古运河枢纽暗涵为大型输水涵洞，根据暗涵明挖段施工实践，从基础处理，混凝土原材料控制，混凝土配合比，模板工程，混凝土浇筑，到温度控制，混凝土养护等方面采取了系统有力的措施，有效地防止了混凝土裂缝的发生，保证了工程质量。

Crack Control in the Water-Transporting Culvert of the Ancient Canal Pivot

The underground culvert of the ancient canal pivot in the Mid-Route of the South-to-North Water Transfer Project was a large type water-transporting culvert. Based on the constructing experience of digging for underground culvert, and adopted many measures, such as basic treatment, controlling of concrete materials, concrete mix rate, formwork project, concreting, controlling of temperature and concrete maintaining, to avoid concrete crevice effectively and ensure the proiect quality.