The mechanical behavior of supporting system for closely adjacent tunnels is the direct indication of its safety in the excavation of diverging tunnels; combined practical work of Miaoya diverging tunnel with small interval in Hu-Rong Expressway

the lateral reinforcement theory of inter-space rock and site monitoring of closely adjacent tunnels are introduced; based on the results

the deformation of surrounding rock and mechanical behavior of supporting system are presented; together with the study on the field experiments for blasting vibration of inter-space rock

the stability of closely adjacent tunnels is evaluated; and the conclusions obtained will devote to the following studies.