ASSESSMENT OF SAFETY RISK MANAGEMENT MODEL (SRMM) IN THE CONSTRUCTION OF TEHRAN MOTORWAY TUNNELS–A CASE STUDY

摘要: With increasing urban development, especially in metropolises such as Tehran, the construction of urban motorway tunnels is increasingly being considered. However, the construction of this tunnel is always considered as one of the most challenging construction activities and associated risks. Arash-Esfandiar-Niayesh Tunnel (AENT) is the first double deck urban tunnel in Iran. The safety risk management of this tunnel faced lots of challenges including: 1) the waste water channel, qanats, pipelines and surface and subsurface facilities (eg, Tower, Cable and etc.), 2) high traf ic areas with a small overburden, 3) surface structures with high sensitivity and 4) change geometry along the tunnel. In this regard, at the first, by taking advantage of a comprehensive study of geotechnical and geological engineering, a database and a geological model of the tunnel route was prepared. In addition to that, high-risk areas, substructure and surface structures sensitive for displacement, identification and warning level were defined according to the type and importance of each of these structures. In addition, finite element modelling was used to modelling the construction method with the approach of selecting the optimal method for controlling displacements. The results of the numerical modelling have been modified via using a monitoring system. Finally, by utilizing of this process in study, the construction of tunnel conducted with minimal risk and according to schedule.