Impact of pit supporting SMW pile construction on underneath shield tunnel deformation

Taking the project of Xinggangjie tunnel up-crossing No. 1 subway shield tunnel in Suzhou as the research object, the deformation data of underneath shield tunnel during SMW pile construction are analyzed, and the deformation rules during SMW pile construction process, cross-sectional and longitudinal deformation characteristics, are discussed during and after SMW pile construction.The results indicate that the deformation of shield tunnel is influenced by the disturbance of SMW pile construction and the mechanical loads. The subsidence of underneath shield tunnel gradually increase during SMW pile construction process, especially at the stage of SMW pile construction at both sides of shield tunnels, the subsidence rate is, a small deformation occurs above the tunnel, and a slight rebound occurs at the end of SMW pile construction. The deformation of shield tunnel in reinforcement area is larger than that in non-reinforcement area, the transverse shape is in a state of vertical compression and horizontal elongation, and the contour of the tunnel is an ellipse whose long axis is nearly horizontal.