ABSTRACT
When a hard rock TBM encounters difficult ground conditions, excavation must be stopped until the completion of ground stabilization work. Such trouble obstructs to make full use of the merit of TBM’s high-speed excavation. Whereas conventional tunneling is inferior to TBM in drilling speed, conventional tunneling can be adopted flexibly to complex geology by installing appropriate tunnel supports. Authors have developed the world’s first hybrid excavator which can convert TBM mode into conventional tunneling mode according to the geological change. This excavator performs high-speed drilling in TBM mode for hard rock excavation and this can convert to conventional tunneling mode for weak ground excavation. Weak ground can be excavated by the operation of the bucket equipped inside the machine and tunnel supports can be installed immediately afterwards. In this paper, we will explain the detailed mechanism of the excavator and introduce the plan of adaptation to an actual tunnel.
