New Cooling Method of Constructing Multiple Internal Holes Combined with Water Injection/Air Ventilation for Mass Concrete Temperature Control and Its Application to Canal Navigation Walls

Abstract

Controlling temperature and preventing cracking of mass concrete are critical research topics in hydraulic structures. A new combined temperature control technique of constructing multiple internal holes combined with water injection/air ventilation for mass concrete was introduced in this study. The efficacy of this technique was investigated by applying it to a canal navigation wall. Initially, a thermal-stress coupling finite element analysis method was employed to simulate the temperature field of multi-hole concrete placement blocks with various cooling measures. The accuracy of the numerical model and calculation method were validated using a field prototype test with a maximum temperature error of less than 5 %. Subsequently, a series of numerical case studies for an entire multi-hole navigation wall were conducted to analyze the effectiveness of various combined cooling measures during the construction phase. The mechanical behavior and the safety of the multi-hole navigation wall were also analyzed. The results indicate that the water injection (WJ) measure is the most effective combined means for temperature reduction in multi-hole structures. The application of this new technology to the overall structure of a navigation wall can reduce the maximum internal temperature (Tmax) by 3-7% and surface tensile stress (σS) by 6-14%. This, in turn, significantly reduces the risk of cracking. During the operational phase, the safety factors against sliding (Ks), overturning (Ko), and buoyancy (Kf) of the multi-hole navigation wall satisfied the standard requirements. These results provide a scientific basis for the application of this new temperature control technology.