关键词: 引水隧洞, 二次衬砌混凝土, 温度应力

Abstract: As an important hydraulic structure, the diversion tunnel exhibits particularly prominent cracking issues in thin-walled structures such as secondary lining concrete. Under the effects of high ce ⁃ ment hydration heat, environmental temperature changes, and strong constraints from surrounding rock, the secondary lining concrete is highly susceptible to cracking. This study focuses on the secondary lin ⁃ ing structure of the water diversion tunnel of Quanshui Dam. Finite element method is used for model ⁃ ing, calculation and analysis to evaluate the risk of cracking in the secondary lining concrete. Combined with process optimization measures, a comprehensive crack control plan for the secondary lining con ⁃ crete is finally formed. The results indicate that step-by-step construction reduces the temperature peak at characteristic points at the bottom of the secondary lining, thereby significantly reducing its cracking risk; the increase in pouring temperature leads to a greater temperature drop, exacerbating the risk of concrete cracking. Relevant research can provide references for engineering construction.

Key words: diversion tunnel, secondary lining concrete, thermal stress