Centrifugal Modelling Of Deep Foundation PIT And Adjacent Inclined Arch Interaction Mechanism Of Pile Foundation

This paper based on the background of Shuangliu Airport Station foundation pit of the Chengmianle passenger line CMLZQ-5 tenders and the skew arch foundation of the T2 terminal which is under-construction,according to the influence of excavation to the pile foundation on adjacent,using centrifuge model tests to special research. Experiments adapt the soil micro deformation photogrammetric methods in the Geotechnical centrifuge model box and test system which are specially developed for tests.The test system contains soil micro deformation photographic imaging device and motion control system,as well as a set of special loading device suitable for centrifuges operating state.The test method can be used to measure the micro deformation of soil in the level of micro-deformation 0.001mm, and meets the special requirements of the test which is proved to be successful.Centrifugal model experiment was respectively carried out on the following six different conditions:1) skew arch foundation is not loaded, excavation; 2) The skew arch foundation under 100% maximum load, no excavation 3) skew arch foundation under 50% maximum load, excavation; 4) skew arch foundation under 100% maximum load, excavation; 5) skew arch foundation under 100% maximum load, excavation, jet-grouting pile soil reinforcement; 6) skew arch foundation under 100% maximum load, foundation pit excavation, jet-grouting pile and isolation of soil reinforcement. Focus on monitoring of the pile foundation and the deformation law and force of foundation pit.The test results and numerical results confirm each other. With the comparative analysis of field monitoring data,it can provide the experimental basis for the qualitative analysis of excavation and pile oblique arch mechanism.The soil micro deformation Photogrammetry in the Geotechnical centrifuge model box and test system is prove to be successful. The results show that the station excavation compared with the terminal pile cap load, the latter is the main cause of large displacement of pile caps. By model test, jet-grouting pile and the isolation pile of soil reinforcement can have obvious reinforcement effect, displacement control is the most effective and can satisfy the requirement of the project special displacement.