ABSTRACT
Shin-Nagasaki Tunnel is a mountain tunnel which has an inclined shaft for construction. Main tunnel between the start portal side and the intersection of inclined shaft was excavated right under residential areas from ranging between 85 and 135 m depth by blasting. Excavation from the intersection to the start portal side was blasted by high precision electronic detonator for environmental conservation to densely populated areas. The main tunnel between the end portal and the intersection of the inclined shaft was excavated directly under residential areas from ranging between 5 and 35 m depth by mechanical excavation and was employed the all ground fasten method for countermeasure against small overburden.This paper reports consideration of construction method, deformation monitoring and excavation situation of the mountain tunnel right under residential areas.
