Large-Scale Model Testing and Analysis of Temperature-Induced Shrinkage Stress in Concrete Raft Foundations Constructed Using the Alternative-Bay Construction Method

In order to investigate the distribution and development of temperature-induced shrinkage stress in concrete raft foundations constructed using the alternative-bay construction method， large-scale model experiments and analysis were conducted in this paper. Firstly， a reinforced concrete raft test model was designed employing both the alternative-bay construction method and post-pour strip construction method. The temperature and stress-strain variations of the structure were measured and analyzed， and the stress distribution patterns of different construction methods were compared and analyzed. Secondly， a numerical model based on the finite element software MIDAS FEA was established and verified against the experimental results. The research results indicated that under the two construction methods， the temperature and stress development trends of the concrete bottom slab section were similar， as were the magnitude and distribution of stress along the slab length. However， due to changes in constraint conditions， the stress variation pattern in the post-pour bottom slab of the alternative-bay construction method differed from that in the other slabs， with the stress in the middle section being greater than that in the post-pour strip method. Therefore， when using the alternative-bay construction method， it is necessary to control the stress in the middle section to ensure it does not exceed the tensile strength， thereby preventing cracking in the bottom slab.