Numerical Simulation And Analysis To The Displacement Of Adjacent Buried Pipeline In Deep Foundation Excavation Engineering

Ground settlement and soil movement induced by deep foundation excavation in metropolises will have negative influence on surrounding buried pipeline. Applying the traditional design theory (strength-controlling design) and routine construction technology, there is inevitable difficulty about protecting the buried pipeline. Many scholars, engineers and technicians have already worked a lot in the displacement-controlling design of deep foundation excavations in recent years, however, there are still many problems in finding the displacement laws in which bracing structure, soil and buried pipelines are taken into account. Based on the special geotechnical software FLAC3D and assisted by the inside language Fish, the response of buried pipeline to deep excavation are studied in this paper. The deep excavation pit supported by diaphragm walls with grouted soil anchor, typical geological conditions of Beijing area are simulated and analyzed. The study put the deep foundation excavation, bracing structures and adjacent pipeline into one system and many factors which impact the buried pipeline are taken into account. According the gotten laws two protection methods are analyzed by FLAC3D numerical simulation. The simulated factors include:the step of soil excavation,distance between pipe and excavation pit, depth of pipe below ground surface, the position of earth anchors, the depth of diaphragm walls below the soil, the dimension of the excavation pit and different load on the soil near the pit. The two protection methods, the reinforcement to the soil inside the pit and the reinforcement to the soil near the pit are also analyzed by numerical simulation with Fish program. By the simulation, the displacement laws of buried pipeline under the factors which have been given former are got. And also the displacement laws of buried pipeline under two protection methods are gained. Some meaningful results for engineering practice are also given in this paper. Considering the absence of the study about the displacements of the adjacent buried pipeline during the excavating process of deep foundation excavations, the result can be used as reference for the relevant numerical simulation and other research.