Abstract:Taking the foundation pit design of the functional improvement project of the National Medical Center - Shanghai International Medical Science and Technology Innovation Center and Xietu Road Bus Parking Lot as examples, the pit is located near the tunnel section of Metro Line 7. The conventional design scheme requires that the foundation pits on the metro side be controlled within three small pits, each not exceeding 1000 m2, but too many pits will increase the construction period. To accelerate the construction progress, the idea of simultaneous excavation of three foundation pits and diaphragm wall chiseled as dug is innovatively proposed for the project. At the same time, a steel servo system is used to ensure the rapid formation of the support system. Under the premise of ensuring that the impact of foundation pit excavation on Metro Line 7 is controllable, the construction period and cost are saved. At present, the pouring of the base plate of foundation pit on the metro side has been completed. The foundation pit adjacent to the metro side has been completed from excavation to the pouring of the base plate, and its additional deformation is controlled within 10 mm to meet the protection standards of metro, which further validates the rationality of the pit merging design adopted in this project.
