More than two-thirds of the TBM bored section on Line 4 of São Paulo Metro has been completed, with shield excavation due to be completed on schedule by next June.
The 9.46m diameter EPBM was launched in early 2007 near Faria Lima station and has driven east more than 4,300m, passing through Fradique Coutinho, Oscar Freire, Paulista and Higienopolis-Mackenzie stations.
Seli’s crew driving the Herrenknecht shield for the Odebrecht-led joint venture contractor has been pushing progress since March when it was relaunched after a lengthy stop at Oscar Freire. It reached the station a year ago.
In May, the EPBM holed through at Paulista and then proceeded to Higienopolis-Mackenzie, which it reached in late August. Cover to some sections of road reduced to 4m, said JV contractor Consorcio Via Amarela (CVA). The shield was relaunched recently and is en route to Republica with approximately 1,900m left to bore.
Geology along the alignment typically comprises Tertiary soils of silt and sand along with gneiss of the São Paulo and Resende basins. CVA said the next sections have critical, softer geology and will see the alignment pass very close to old building foundations in the downtown area.
Tunnel lining is segmental (7+1) concrete of 8.43 i.d., each ring being 350mm thick and 1.5m long.
When it reaches Republica the shield will be pulled through, and then it will be again at Luz station, before then being relaunched for the last time to then terminate just beyond at the ventilation shaft at Joao Teodoro.
CVA is building the metro extension, which is a single bore, twin-track line. In total, Line 4 will have a total length of 12.8km and, eventually, 11 stations. The new line will boost the capacity of the city’s metro network by approximately a fifth (T&TI, April, p8).
Seli was awarded the tunnelling contract just over three years ago for US$410M (2005 prices).
Separately, further investigation into the collapse at the Pinheiros station tunnel, the Line 4 project attracted loans from the World Bank (US$95M) and the Inter-American Development Bank (IADB) of US$95M and US$129M, respectively. The loan has a term of 25 years following a five-year grace period.
Sao Paulo metro has seen steady TBM progress