The two 4.39m-diameter EBPMs and one 4.8m-diameter EPBM will build a 9.1km-long water tunnel in the west of Bangkok.
To tackle the project’s tight alignments, the TBMs feature active-type articulation that can accommodate the minimum radius curve of 90m and 80m.
The TBMs’ soft ground cutterheads feature a spoke design with a 70% opening ratio and copy cutters to meet the geological conditions of silty clayey sand and very stiff clay to hard clay.
Traditionally reinforced, 250mm-thick by 1200m-wide Universal reinforced concrete segments (4+1) will be installed as the machine progresses and a secondary steel lining will be inserted after completion of the tunnel.
Muck removal, segment transport and supply of consumables will be via rail-bound equipment using battery locomotives.
Following the successful factory acceptance tests, the machines will arrive in Thailand before the end of the year. Excavation is due to start early next year.
The project is a joint venture between Italian-Thai (ITD) and Nawarat (NWR). ITD will operate two TBMs (S105 & S106) and NWR will operate one (S102).
These latest TBMs bring to eight the total number of Terratec ‘tight radius’ machines operating in Thailand.
Designed to increase the water supply capacity, the Ninth Bangkok Water supply improvement project is one of a series of tunnelling projects being undertaken by the MWA to meet increased water demand, reduce leakage and improve water quality in the Thai capital.
