与混凝土坝相比,船闸闸首、泵站类薄壁大体积混凝土结构体型相对较小,但结构型式与受力复杂、约束明显且采用泵送高性能混凝土浇筑,早期混凝土放热量较常态混凝土大且发热快,施工期比大坝更易产生温度裂缝,其防裂设计成为施工质量控制的难点之一。结合在建的引江济淮枞阳船闸上闸首工程,采用三维有限元法仿真分析手段,模拟真实环境、材料、结构、温控措施的影响,分析结构施工期温度场、应力场以及开裂风险,并提出针对性的防裂措施。研究表明,输水廊道、墩墙、空箱及启闭机房周边大体积混凝土等功能性部位为高风险开裂部位,实现控温浇筑、通水冷却以及表面保温的多措并举且差异化控制,能够大大降低其开裂风险,可为引江济淮工程薄壁结构防裂设计提供参考。

Compared to concrete dams, the thin-walled mass concrete structures of ship lock heads and pumping stations are relatively smaller in size. However, their structural forms and stress patterns are more complex, with significant constraints. These structures are constructed using pumped high-performance concrete, which generates more heat and heats up faster during the early stages than regular concrete. As a result, they are more prone to temperature-induced cracks during construction, making crack prevention a significant challenge in quality control. With the upper lock head project at Zongyang shiplock of the Yangtze-to-Huaihe River Diversion Project as a research background, we simulated and assessed the impacts of environment, materials, structure, and temperature control measures by using three-dimensional finite element approach. By analyzing temperature field, stress field, and crack resistance, we developed temperature control measures for the project. Our research identifies some functional areas of the upper lock head structure as more prone to cracking. These areas include the bottom plate, water conveyance gallery, pier wall, mass concrete around the empty box and the hoist room. Implementing a combination of temperature control measures, such as temperature-controlled pouring, water cooling, and surface insulation, with differentiated control strategies, can significantly reduce the risk of cracking. The findings offer valuable reference for crack prevention design in thin-walled structures of the Yangtze-to-Huaihe River Diversion Project.