The second tube of the San Cristobal road tunnel concession in Chile is now operation after additional non-underground works following the first bore having opened almost on schedule last year.
Both 1.8km long tubes on the toll link are operating as planned for the PPP concessionaire, a JV of Hochtief and ACS-Dragados. They were awarded the PPP contract in 2005, which calls for the twin tunnels to be constructed as part of a 4.1km link in north Santiago.
The tunnel consists of the two tubes linked by eight evacuation galleries, two of which are for vehicles, at 200m intervals.
Excavation started in April 2006, and the drill and blast works and mechanical excavation were finished by April 2007, and with lining underway later that year the project was on schedule to fully open in mid-2008, as planned.
However, only one two-lane tube on the link was opened in July last year, only slightly after the planned completion. The projects includes also construction of an additional 2.2km of access roads (T&TI, July 2007, p7).
The second tube was not opened until a series of works were done to alleviate traffic congestion. The tunnel was opened on 30 December, taking the link to full capacity. Costs recently cited are US$125M whereas previously the budget was given as US$91M.
