Numerical Analysis Study On The Slope Stability Of The Deep Super Foundation Pit In The North Of Liangqing Bridge In Nanning

Deep foundation pit engineering is an ancient and modern geotechnical engineering problem which is a comprehensive system engineering, and it involving many aspects of safety, environmental protection, economic construction, etc. In recent years, deep foundation pit engineering has become a new topic in the civil engineering with the construction of skyscraper and underground building in China. A large-scale deep pit will be excavated at first in the construction of basement level and multi-storey buildings, underground shopping street, underground garage, subway stations and so on.In engineering practice, the stability of the foundation pit itself and adjacent buildings and underground pipeline facilities will be kept safely. The study on deep foundation pit engineering is premise and guarantee for the safety, cost and success of construction. In this paper, the index of slope stability about deep foundation pit of northern anchorage in Nanning Liangqing Bridge is calculated by Lizheng geotechnical software at first. And then using of finite difference software FLAC3D, a two-dimensional simulation of the entire excavation process and support of deep excavation is accomplished. The behavior of retaining structure is analyzed, and the deformation pattern of deep excavation is studied in five cases. Finally, based on the FLAC3D software for foundation pit excavation and supporting of step-by-step, the whole engineering process is simulated. The research result as following:the uplift amount at bottom of deep foundation pit, the displacement and subsidence distance on the surrounding surface, axial force distribution of anchor are under permission range with foundation pit slope stability coefficient 1.51. The safety, economic and smooth implementation of the bridge engineering can be ensured with the harmonious development of human and nature.The result above calculation of the largest horizontal displacement of retaining pile is basically same as the real monitoring results in engineering field. The thesis about deep foundation pit slope stability evaluation and reinforcement measures appointed in this paper are maybe a certain referential value for other similar projects.