船闸施工期混凝土开裂风险分析*

针对船闸闸首廊道、闸室墙等结构部位大体积、异形结构易开裂的问题,依托九圩港二线船闸工程,对混凝土早龄期热、力学和变形性能进行了系统测试。在此基础上,模拟评估了温度场、应力场和开裂风险,并与实际监测结果进行对比。结果表明,廊道外侧长墙、闸室边墙混凝土开裂风险主要来自于表面与环境的温差、内外温差产生的温度梯度,以及降温过程中底板老混凝土对边墙混凝土的约束。闸室墙早期表面开裂风险超过1.0,内部开裂风险在23.5 d后达到并超过0.7；廊道左侧长墙早期表面开裂风险达到0.79,内部开裂风险在17 d以后达到并超过0.7。温度、开裂时间实测结果与计算结果基本吻合。

Cracking risk analysis of concrete during construction period for shiplock

Relying on the Jiuweigang second-line shiplock engineering,the thermal,mechanical and deformation properties of early-age concrete were tested;on this basis,the temperature field,stress field and the cracking risk of sidewalls in lock chamber and lock head corridor were simulated,and compared with the actual monitoring data.The results show that the cracking risk of sidewall concrete in lock chamber and lock head corridor mainly comes from the temperature difference between the surface and the environment and between the inside and outside,and constraint from slab concrete.The cracking risk of surface concrete in chamber exceeds 1.0 in very early age,and cracking risk of center concrete exceeds 0.7 after 23.5 days;cracking risk of surface concrete in left side corridor is up to 0.79,and cracking risk of center concrete exceeds 0.7 after 17 days.The simulation results of temperature and cracking time agree with the monitoring results.