Study On Stability Influence Of Foundation Pit Supporting About CFG Piles Construction In The Foundation Pit

With the development of urban construction, the space of underground is used anddeveloped. This must involves deep foundation pit excavation, especially deep foundation pitexcavation happens in some soft soil areas. Protection of surrounding buildings must beconsidered.In the engineering practice, CFG piles must be constructed in the excavated foundation pitaccording to the excavation depth of foundation pit, the design length of CFG pile and makingpile depth of equipment when the base design of substructure uses CFG pile foundation becausethe CFG pile-making equipment do not have ability to construct CFG pile under the foundationpit in the ground. The construction technology can ensure that the CFG pile length underfoundation pit can meet the design requirements. But, monitoring data of foundation pit showsthat the construction of CFG pile in excavated foundation pit has influence on environmentsurrounding foundation pit. This affects mainly displays that crack appears in the groundsurrounding foundation pit. These cracks bring inconvenience to residents, affecting theprogression of construction seriously and making a certain economic loss to the construction unitand owner.Therefore, MIDAS/GTS software is used to construct a three dimensional finite model offoundation pit to simulate actual construction of the CFG pile in excavated foundation pit basedon the working mechanism and construction technology of CFG pile. The stability of foundationpit supporting with the construction of the CFG pile in foundation pit is studied.Firstly, the theory and function of MIDAS/GTS software are explored, which is applied tosimulate the actual construction of CFG pile in excavated foundation pit. Combined thegeological exploration data of a deep foundation pit engineering, the actual support design dataof foundation pit and the practical construction technology of this engineering, a threedimensional finite model of foundation pit is constructed to study the stability of foundation pitsupporting with construction of the CFG pile in foundation pit. The deformation of soilssurrounding foundation pit and the deformation of foundation pit bracing structure and thesurface settlement deformation around foundation pit are studied. And the monitoring data of actual engineering is compared with the simulating results. At the same time, the location of thecrack is pointed out and the cracking reason is analyzed.In view of crack problems appeared in actual engineering, the other two schemes differentfrom the practical engineering project are put forward and simulated by finite model tofoundation pit. The reasonable process of the CFG pile in excavated foundation pit is analyzed.Ina word, the problem of the stability of foundation pit about CFG pile construction in theexcavated foundation pit is studied and the conclusion has the practical guiding significance forsimilar engineering.