TUNNEL CONSTRUCTION, SUBSIDENCE PREDICTION AND MONITORING BENEATH DENSELY RESIDENTIAL AREA

Abstract

Higashiyama Tunnel is a twin highway tunnel having two lanes each which passes through under unfavourable ground conditions at a shallow depth of cover beneath densely residential area in the eastern part of Nagoya City. In order to preserve the residential environment, especially to restrict surface settlement, the tunnel supporting systems were designed containing a combination of up-to-date supplementary tunnelling techniques. During the tunnelling procedure, a construction monitoring programme was implemented to evaluate the adopting tunnelling methods, to predict the ground behaviour and to assist in the revising of construction methods for further excavation. This paper describes the tunnelling method adopted in urban area and the analysed results of the ground behaviour induced by tunnel excavation.