水闸属于薄壁大体积混凝土结构,实践表明,若不采取温控措施,尤其是低温季节施工的混凝土水闸结构在浇筑初期极易出现表面裂缝,后期易扩展为贯穿性裂缝。弄清各温控措施对水闸温度场、应力场及开裂风险的影响,是制定水闸温控指标和防裂措施的前提。以某在建的低温季节浇筑水闸工程为研究对象,利用三维有限元法,计算分析了在低温季节浇筑施工时水闸结构的温度场、应力场特性,重点进行了开裂风险的敏感性分析。结果表明,单一温控措施的防裂效果有限,控温浇筑、表面保温、冷却通水必须相互协调,能有效控制水闸温度应力并避免裂缝产生。

Sluice is a large-volume concrete structure with thin walls. Practice have shown that concrete sluice structure constructed in low-temperature season is subjected to surface cracks in the early stage of pouring if no temperature control measure is taken, and such surface cracks would penetrate through in later stage. To clarify the influence of temperature control measures on the temperature field, stress field and cracking risk of the sluice is the prerequisite of determining temperature control indices and formulating anti-cracking measures. With a sluice project under construction in low-temperature season as a case study, we examined the spatial and temporal characteristics of temperature field and stress field by simulating the construction process using 3D finite element method. On this basis, we analyzed the sensitivities of stress to pouring temperature, surface temperature preservation, and water cooling. Results manifested that single measure has limited effect. Multiple measures including temperature-control pouring, surface temperature preservation, and water cooling must be coordinated to effectively control the temperature stress of the sluice and avoid cracks.