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.