Yuki SOMA

Simulation of Shield Behavior in Sharp Curve by the Kinematical Shield Model

Mitsutaka SUGIMOTO

�@Due to the congestion of underground structures and the limitation of underground space for constructions in urban area, deep underground space has been used and the tunnels with sharp curves have been constructed recently. Articulated shield is usually adopted for tunnel construction at a sharp curve. Articulated shield can be divided into front body and rear body. To construct tunnels along planned alignment during excavation at curved area, front body is bended against rear body to excavate the ground smoothly at a curved alignment. Shield is advanced by jack forces and copy cutter excavates the ground at the concave side of a curved alignment. Then so far, these operations are used to be conducted using expert system based on engineers or automatic excavation system. However, there is no theoretical background to control shield since these systems are based on empirical way. Therefore, it is difficult to control shield behavior under complex conditions. Furthermore, it is considered that the demands for construction in deep underground space and adjacent construction near existing structures will be increased. Conventional control method of shield needs to be changed to theoretical control method, which takes force equilibrium conditions into consideration.
�@The kinematical shield model had been developed through the previous researches. In this study, to confirm the validity of the kinematical shield model, the shield behavior was simulated by applying the site date to the kinematical shield model and the calculated results were compared with the measured data, which was obtained at a sharp curve in steep slope alignment. As a result, the following conclusions were obtained: By setting appropriate conditions, the behavior simulation can reproduce the behavior of the actual shielded machine, so the validity of the model was verified.