The 6.68m diameter shield to be used on the first drive of the Shiraz metro project in Iran was assembled by the end of May. Manufacturer Wirth won the US$20.3M supply contract in October 2002 for two EPBMs with its French affiliate NFM Technologies. The drive unit was also being assembled in early June for the second TBM that will be used on the project.
Of the 23km line, client, Shiraz Urban Railway Organisation (SURO), will construct 15km in twin tunnels in two project phases. 11km of tunnel will be mechanically driven.
Contractor, Bamrah, will have to negotiate the TBMs through mostly clays and sands. The two different formations can be distinguished by varying coarseness, from gravel to a finer soil composed of pure silt and loam. Major faults are not expected and the tunnels will be lined with reinforced prefabricated concrete segments.
Colcrete Eurodrill has supplied four colloidal bentonite mixers, two for each EPBM. Each pair will produce a target of 50 cubic meters of bentonite per hour per machine.
The project will give Shiraz, in the Pars province of Iran, its first ever metro line. With an approximate population of 1.2M inhabitants in the city, it is hoped the metro system will relieve the severe road traffic congestion and improve environmental conditions associated with car exhaust pollution.
