Abstract:

 In order to solve the problems in the mechanized construction of a threelane rectangular crosssection tunnel, the key systems of a superlarge rectangular crosssection pipe jacking machine with 15 m span are studied. To solve the excavation problems of the superlarge rectangular crosssection pipe jacking machine, a mathematical model of combined cutterhead distribution and the control strategy for low interference are built, and a lowinterference excavation system of superlarge rectangular crosssection pipe jacking machine is developed. Based on the regression analysis of the drive torque data, the calculation method for the drive torque of the combined cutterheads with the overlap rate introduced is proposed. In order to solve the problem of nose down due to the overweight shield structure during tunneling, the finite element design method based on sensitivity is used to realize the lightweight design of the superlarge crosssection shield structure. Aiming at controlling the pressure in the excavation chamber of the superlarge rectangular crosssection pipe jacking machine, the multiple screw conveyor coordinated control system and the machine attitude control strategy suitable for largespan pipe jacking machine are developed to solve the problems such as attitude and ground settlement control during the construction of the superlarge crosssection tunnel. Furthermore, corresponding rectification solutions for muck discharge and pipe alignment problems in the application of the pipe jacking machine are put forward. In a summary, a superlarge rectangular crosssection pipe jacking machine has been successfully developed and applied for the project.

Key words: superlarge rectangular crosssection pipe jacking machine, excavation system design, shield structure lightweight design, settlement control, attitude control