Case study of support system of deep foundation pit of Beijing Century Building

Based on the support system of deep foundation pit of Beijing Century Building with excavation depth of 19.95 m, the ground situation and surroundings as well as the situation of engineering geology are analyzed concretely. A comprehensive support plan combining the soil-nailing walls with pile-anchor system is proposed to make use of their respective advantages. The technique of artificial excavated piles is adopted to adapt to the cobble stratum so as to solve the problems aroused by power drilling. The maximum value of horizontal displacement is only 12.1 mm, and the mechanical properties of each support element are all in satisfactory. The results illustrate that the design is reasonable and the displacement of the pit is controlled effectively. The experience is valuable to similar projects.