Abstract：
Taking Hongpailou open-cut foundation pit above existing parallel metro in Chengdu city as an example, three-dimensional modeling utilizing FLAC3D was performed to investigate the stability on account of various measures. Inspection of modelling results reveals that grouting reinforcement can be capable of improving the stiffness of pit bottom and soils around existing metro, and reducing the influence of up foundation excavation on the existing metro structure. The construction associated with anti-floating pile, anti-floating beam as well as excavation by steps can be beneficial to clean thoroughly pit bottom, and form the frame structure of similar umbrella, so that it declines the unfavorable effect on the existing metro.
