Numerical Analysis Of The Existing Adjacent Frame Structure In Foundation Excavation And Construction

Accompany with the advance of China's urbanization process, Many foundation pit in the dense cluster of buildings, adjacent to the existing buildings and municipal facilities, the foundation excavation not only related to their own safety, also impact the near buildings. The form of a row of piles and prestressed anchor support, foundation, soil and adjacent framework are considered as a whole with FLAC3D, simulation the horizontal displacement of the supporting structure, the surrounding ground surface subsidence and the displacement of adjacent frame structure by two ways which different excavation ways and different distances between foundation and framework. Use three-dimensional finite element software SAP2000analysis frame structure's internal forces when the foundation excavation has been done, it base on the before results. The main conclusions are as follows:1. In the numerical simulation, you can take the board model instead of the pile model with the same lateral stiffness. The former to deal with weak software to improve the modeling efficiency.2. The comparison of different excavation:the island excavation can effectively reduce the horizontal displacement of the supporting structure, the surrounding ground surface subsidence and the vertical deformation of the building; basin excavation can reduce vertical displacement of the frame structure. Overall excavation, island excavation and basin excavation can effectively reduce the tilt of the building than the other ways. Also, the effects due to excavation depth, the deeper you excavate, the smaller difference impact it has.3. The displacement of the pit and the adjacent buildings along with the increase of buildings and excavation distance decreases, and2-3times the excavation depth of this influence from the pit inflexion, that the inflection is more obvious at the left side of inflection point than the other side. Response to this paragraph regional construction projects to enhance monitoring.4. The influence of the axial force, shear and bending moment is decreases from the bottom up, and the bottom most obvious, it is foreseeable when the frame structure to achieve a certain number of layers the upper floors will not be the excavation. This also shows that the adjustment of the structure's internal force is limited to number of layers in the bottom and the finite stiffness.