A Study on Deformation of the Meridian Gate’s Platform in the Forbidden City Based on Long-Term Monitoring Data

Located on the north–south central axis of Beijing, the Meridian Gate is one of the important buildings in the Forbidden City. For exhibition and communication purposes, a new exhibition hall was added to the main building of the Meridian Gate in March 2005, following scientific demonstration. Based on long-term monitoring to the Meridian Gate’s platform, including deformation, water level, and temperature data, as well as structural surveys, it has been determined through analysis that there has been no significant deformation of the platform as a whole during the monitoring period. The interior of main building on the platform is constructed of blue bricks, and the brick wall layers are the same as the material used for the platform’s core, resulting in good overall homogeneity. The deterioration of the brick wall layers and localized three-dimensional deformation of the platform are mainly attributed to the long-term effects of water and temperature changes.