TEHRAN METRO LINE7 SOUTH-NORTH SECTION EPB TBM TUNNELING IN A HIGHLY CONGESTED AREA OF THE CITY. PRODUCTIONS, SETTLEMENTS CONTROL AND LOGISTIC PROBLEM

The present paper deals with the underway tunnel execution of the South/North section of the Line 7 of Metro Tehran. SELI, as mechanized tunnel excavation expert, has been appointed by SEPASAD Co. to supply the equipment necessary for the Tunnel excavation and to carry on the execution of the TBM tunnel. One EPB-TBM has been chosen to perform the excavation of the tunnel. The tunnel excavation started on may 2010 and at the moment almost 3,5 km have been bored. The excavation in EPB mode, the daily surface settlements control and the logistic problems are the topics of the project.SEPASAD Engineering Co. is the Main Contractor for the execution of about 14km long Tehran Metro Line 7 South-North Section while the Client is the Tehran Urban and Suburban Railway Co. (Municipality). The Line 7 South-North Section develops the about 14km of Metro Tunnel along the South-North city axis and from the Station N7 (Navaab Road) to the Station Y7 in North of Tehran. The used TBM is an EPB (Earth Pressure Balance) with the excavation diameter of 9,164m and the lining is with pre-cast concrete segments following the concept of the Universal Ring. The tunnel route is mainly along highly traffic congested road with some diversions corresponding to the crossing of the existing or under construction Metro Lines (Line 2 and Line 4) and existing other facilities and structures (as the Tohid underpass road tunnel). Is then clear the sensitive importance of the monitoring within a complex frame due to the severe logistic conditions