Numerical Simulation for Temperature Control and Crack Prevention of Tunnel-Lining Concrete During Construction

This paper develops a three-dimensional refined finite-element model for the typical concrete lining of the Dianzhong Water Diversion Project tunnel, investigates the temperature and stress fields of the lining, and systematically analyzes the influences of various temperature-control measures and construction conditions on both fields. The interface between the surrounding rock and the lining is simulated using thin-layer contact elements. The results show that the rock temperature beyond a depth of 6 m is not affected by concrete hydration. The maximum temperature of the lining poured in the inner section is 6.36 °C higher than that poured at the entrance section. Concrete with micro-expansion and low adiabatic temperature rise, as well as pouring during low-temperature seasons, is beneficial for the anti-cracking safety degree of the lining. The temperature stress increases with the pouring temperature: when the pouring temperature rises by 4 °C, the minimum cracking safety factor decreases by 0.25. For this project section, the appropriate segmented length of the lining structure ranges from 8 m to 10 m. These results can provide guidance for the construction of tunnel linings to improve their anti-cracking safety degree.