To Research: Deformation Rule And Control Measures Of Deep Excavation In Ningbo Soft Soil Based On Field Measured Data

With the development of urbanization and urban construction, more and more attention hasbeen paid on the exploiting of urban underground space. Rencenly, large-scale subway station,underground parking garage, underground shop and so on are built and a lots of foundation pitscome into being among which the foundation pits of subway stations is the main style in thebuilding of foundation pit. There exists four trends in the foundation pit engineering, i.e., thefoundation pits become deeper, the scale of constructions is getting larger, the distance betweenbuildings and foundation pits is getting closer and the hidden troubles are more and more. Therefore, the safety problem of foundation pits is one of the scholar’s key points.As a middle-sized city in east of china, there is a high-speed development of economy inNingbo city, and its urban construction is advanced with each passing day. Now, the rail transitproject. is being constructed, the controling of deformation in the foundation pits is the key point toassure the safety and stability. Therefore, horizontal displacements of diaphragm wall, groundsettlements diaphragm wall, effect factors and deformation control measures are investigatedsystemly in this paper based on tgathering and analyzing a great lot of field data, constructiondocument and conditions of15foundation pits of the deep excavation of underground stations inNingbo rail transit by using the method of data mining the deformation rules of these deepexcavations. The paper researches through gathering and analyzing a great lot of field data,construction document and conditions of15foundation pits. Primary content includes several partsas follows:(1) Tthe present situations are comprehensively summarized on deformation controlling indeep excavation based on relative studies. Then, that the the horizontal displacements of diaphragmwall and ground settlements behind diaphragm wall should be mined mainly is pointed when thedeformation rules of deep excavation in Ningbo rail transit are discussed.(2) Based on the engineering characteristics of Ningbo soft soil, the importance of monitoringto assure the safety of excavation is elaborated. Then, the information monitoring technique,dealing process of data mining technology and algorithm principle of relative calculation models,are introduced whcich can provide a foundation for mining the deformation rules of deepexcavation.(3) On the basis of monitoring data in Ningbo urban rail transit, the basic rule of horizontaldisplacements for diaphragm wall are analyzed using the mining technology from the aspects of accumulative value of deformation and rate of deformation,. Furthermore, the basic law of groundsettlement behind diaphragm wall of deep excavation is presented, and the influence factors arealso discussed.(4) According to the construction condition of deep excavation of Ningbo rail transit, theinfluence of four basic factors, i.e., thickness of diaphragm wall, foundation reinforcement,foundation pit dewater and over loading are discussed on the excavation deformation.(5) The deformation control measures that are suitable to deep excavations in Ningbo soft soilfrom design and construction are presented form the design and construction according to theconstruction condition, the monitoring data and the available deformation control measures.