Abstract:

With the fast increasing of urban underground space developments in China, a new kind of underground construction, deep excavation group, has been developed, which means a group of adjacent / related excavations constructed at the same time or the super-large excavation divided into small pits. The excavation groups are divided into three kinds according to the special relation of different parts, including the divided, jointed, and adjacent ones. Based on the project of Shanghai International Aviation Centre excavation group, the deformation characteristics of divided excavation groups which is one of the typical types, was studied by statistical analysis method of field measured data in the research. The deformation of partition walls, lateral displacement of underground walls and ground settlement during construction were studied in detail and their differences in different location were analyzed. The differences between traditional excavation and the excavation group were also compared in the research. Research shows that the deformation of partition walls increases first and then decreases, and it is affected by the nearby excavating. In the partition zone, the average maximum lateral displacement of the undergroud wall is 0.16%H, which is smaller than the average of 0.60%H in Shanghai and the average maximum ground settlement is 0.14% H, which is also smaller than the average of 0.40% H in Shanghai. The study provides a very strong reference value for other excavation group construction and protection of sensitive buildings.

Key words: excavation group, partition wall deformation, underground wall deformation, ground settlement