Desiree Willis, Technical Writer, The Robbins Company

The city of Baku in Azerbaijan is to renovate canal tunnels using the country’s first ever TBM. The Robbins EPBM is supplied to contractor Azerkorpu which expects to use the machine on several other needed tunnelling projects in the country.

Azerbaijan’s first-ever TBM

For centuries a lack of surface water has led to intensive use of groundwater for irrigation in Baku, Azerbaijan. The Samur-Apsheron Irrigation Project will help remedy current water problems by overhauling a main canal that provides water supplies to Baku. New tunnels will be built using a 6.3m (20.7ft) diameter Robbins EPB—the first-ever TBM to be used in Azerbaijan.

Contractor Azerkorpu awarded Robbins the contract for the complete EPB boring system in June 2008. The TBM order includes all associated and ancillary equipment including the trailing back-up, cutting tools, segment molds, segment manufacturing plant, rolling stock, ventilation system and spares. It also includes a team of experienced and professional TBM operating personnel.

EPBM with foam injection

Major components of the machine, including the main bearing, electrical, and hydraulic systems, were procured in the US, Europe, and Japan. Assembly was completed in April 2009 by the Robbins EPB Division in Guangzhou, China.

The TBM is scheduled for a summer 2009 launch and is expected to bore for eight to nine months in hard clay, silt, sand, and mixed face rock. The machine features a mixed ground cutterhead with interchangeable disc cutters and carbide bits. Four independent foam injection points in the cutterhead evenly consolidate the face in varying ground conditions. Multiple detection systems provide electronic information about clogged ports, preventing unnecessary cutter and cutterhead wear.

At the Robbins factory in Guangzhou

The machine will excavate one tunnel of approximately 3.5km and line it with 300mm thick rings of precast concrete, universal type segments, five segments and a key in each ring. Once the tunnels are complete in 2010, Azerkorpu plans to use the EPB on several other projects in the country.

The Samur-Apsheron Irrigation Project, for the Azerbaijan Government’s Irrigation Department, consists of open canals and TBM-driven tunnels totaling 5.7km (3.5 miles). The network will convey water from the Samur River to use for both irrigation and the new Takhtakerpu hydropower station that will provide power to the Cusar District in Baku.