John Holland has ordered an EPBM from Lovat for a sewer contract in Melbourne and the Canadian TBM manufacturer also reports that another shield has completed about three-quarters of the first leg of a larger sewer in Coslada, Spain.
Lovat is to supply John Holland with a 2.92m diameter mixed face EPBM for a 2,088m long sewer entirely below groundwater. The head over the invert level is 9m-11m, and the depth of cover over the crown is 8m-12m.
Geology along the route comprises the Yarra Delta Group, which typically comprises a range of marine and estuarine sedimentary deposits – sand, silt, clay – and may also include some basalt.
The machine (RME115SE) will be equipped with a four-spoke, chromium carbide-plated cuttinghead fitted with backloading rippers, which are interchangeable with 15.5” disc cutters. In addition, the shield will have a two-stage, two chamber integral airlock. It is to be delivered early next year for the Melbourne Main Sewer Replacement project.
In Spain, the manufacturer reports that on the Coslada sewer project its refurbished 4.7m diameter EPBM has bored more than 70% of the 2,250m long first section of tunnel. Lovat said breakthrough is expected by late September.
Best rates achieved for a day, week and month were 32 rings, 122 rings and 336 rings, respectively, said Lovat. The TBM was launched in February. The contractor is working two-11 hour shifts on weekdays. Sando said the average progress rate is 21.2m per day and the tunnel depth is 23m.
The second, and final, bore for the RMW185SE Series 20202 machine is 1.4km long.
Geology along the first drive comprises mixes of highly plastic clays and gypsum with each other and, separately, with water. The ground along the second drive comprises silty sand and fractured gypsum.
The project is part of the development of the El Canaveral housing project, one of the largest in Spain, according to Sando.
