Abstract: The accurate prediction and effective control of the surface settlement caused by the construction of large crosssection rectangular pipe jacking are of great significance. As a result, the vertical deformation of strata caused by construction of rectangular pipe jacking project of utility tunnel of Chengbei Road in Suzhou under multiple factors is studied based on analysis methods such as mechanical theory, measured data and numerical calculations. Based on the Mindlin solution and stochastic medium theory of elastic mechanics, the soil deformation mode around the pipe is explored, and the calculation formula of vertical strata deformation caused by additional stress on the front of pipe jacking, lateral friction, formation loss, and grouting filling is deduced. The field measured data show that the calculation method is feasible. Furthermore, the Matlab is used to numerically analyze the influence of various factors on the vertical deformation of strata, and explore the general law of vertical deformation of strata when the large crosssection rectangular pipe is jacking. The results show that: (1) The theoretically deduced analytical formula for vertical deformation of strata basically conforms to the actual law on site. (2) The influence of formation loss on surface soil settlement is the largest, followed by that of friction between pipe jacking head and surrounding soil. (3) Grouting can have a lifting effect on the surface.

Key words: rectangular pipe jacking, Mindlin solution, stochastic medium theory, grouting filling, Matlab numerical analysis