Construction Monitoring And Numerical Analysis Of Gourd-shaped Pit Diaphragm Wall

Gourd-shaped Diaphragm Wall as a new form of supporting structure of foundation pit, more adapted to the basic structure of economic and security requirements. At present the theory and construction technology of Gourd-shaped Diaphragm Wall none can draw lessons from the successful experience, its deformation and stress characteristics are unclear.To solve the above problem,This paper based on Diaphragm Wall Monitoring Project of Dayue high-speed Dongting Lake Bridge Yueyang side anchorage deep foundation engineering, studied and analysed the Gourd-shaped Diaphragm Wall. Through the commonly used finite element software MIDAS/GTS on the numerical simulation analysis, and monitoring the related indicators on internal force and deformation of the underground continuous wall, comparative analysis the two data, get the deformation and stress characteristics of Gourd-shaped Diaphragm Wall.The study indicates that the stress of Gourd-shaped Diaphragm Wall is mainly circumferential compression stress, lining structure is given priority to tensile stress. Stress increases gradually in the process of foundation pit excavation, underground continuous wall stress distribution is relatively uniform, only in Y-shaped junction and the top of circular arc of the vertical bridge appear relatively large stress concentration, the shape of the underground continuous wall effect on the internal force is limited. Horizontal displacement of underground continuous wall is similar to the hoop stress, in the lower part of wall body is small,the medium and upper is large. As the excavation proceeds, both the maximum point decreased, the maximum increases, and finally stabilized in the vicinity of the excavation face. Though Gourd shape structure of the Diaphragm Wall is not complete circular underground continuous wall, the arch effect of circular arc form effectively limits the wall deformation, deformation trend is slow, low degree of uneven settlement. Numerical simulation and monitoring results both reflect the relative concentration of stress and deformation occurs in the Y-shaped junction, more attention should be paid in the future design and construction.