Abstract: To investigate the evolution process and damage characteristics of complex geology during tunnel boring machine (TBM) tunneling, a micro TBM model test system suitable for complex geological conditions is developed. The system comprises a microtunneling device, multifunctional rock box, microtunneling machine position translation device, quadruple hydraulic system, and microtunneling machine tunneling control system. The system can realize the adjustable advance speed of 0~50 mm/min, the adjustable speed of the cutterhead of 0~10 r/min, the maximum torque of the cutterhead of 1 000 N·m, and the maximum safe driving distance of the cutterhead of 1 100 mm. Furthermore, it can perform halfsection visual tunneling and fullsection high groundstress simulation tunneling and obtain the change law of tunnel stress during TBM tunneling in complex geology in advance, providing a reliable reference for TBM tunneling in complex geology with large buried depth and high groundstress on site.

Key words: long and large tunnel, complex geology, micro tunnel boring machine, test system, simulation test