The Application Of Soil Nailing Support In Deep Foundation Excavation Of Tianfu Square Tunnel

With the development of our country, the process of urbanization is faster and faster, and the conflict of the race of land source is standing out day by day. As the exploitation of underground space and the construction of high-rise building in urban area, a large number of deep foundation excavations have appeared lately. Its scale and depth increase constantly . Urban deep foundation excavations are generally surrounded with dense buildings. So their working space is very narrow, especially when they are close to the foundations of adjacent buildings or structures in construction. Many scholars, engineers and technicians have already worked a lot in the displacement-controlling design of deep foundation excavations recent years, however, difficulty remains to be solved in correlation among the retaining structures, soil deformation around the excavations and the displacements of adjacent structures.Process of the typical deep foundation excavation of Tianfu square tunnel. The construction which is under the typical geological conditions of Chengdu area is simulated and analyzed with the aid of FLAC3D. Soil nailing is chosen as the retaining system. Numerical simulation is carried out the horizontal displacement and the settlement around the foundation. Further more, we find the law of surrounding soil settlements, different settlement and absolute settlements of adjacent structures that may appear in the process of excavation by steps. Finally, the conclusions that are valuable for designing and construction of deep foundation engineering are found. The result can be used as reference for the relevant numerical simulation and other research.