APPLIED LEARNING ON
SÃO PAULO’S
“UNIVERSITY LINE”
The Line 6-Orange metro is one of Latin America’s most ambitious rail projects in São Paulo which will soon link the north to the city center, cutting more than an hour off daily commutes.
TACKLING TERRAIN
The new 15-stop route University Line built by Acciona will provide a fast, modern alternative to existing metro and bus options, but constructing the line has been highly complex. To ensure stability, the 15.3 -kilometer double-track tunnel must withstand soft, waterlogged ground and passes under the Tietê River.
Engineers had to tunnel beneath São Paulo’s fluctuating terrain and through varying soil types, including the region’s sticky taguá clay. Reaching over 60 meters deep in some spots, it will become the deepest line in the city and across the continent.
Solving complex tunneling challenges
Advance soil-conditioning solutions by Sika speeds up tunnelling through the shifting local terrain.
Tackling terrain
The new 15-stop route, nicknamed the University Line and built by Acciona, will offer a sleek and speedy alternative to current metro/bus combinations.
BREAKING RECORD WITH SIKA SOLUTIONS
Most of the double-track tunnel was excavated using two tunnel boring machines, each weighing 2,000 tons and 109 meters in length, with a cutting head over 10 meters in diameter. Despite their power, challenging ground conditions such as abrasive rock, sand, sticky clay, and groundwater required specialized soil conditioning to maintain performance.
Sika developed tailored foaming agents for each ground section and provided continuous on-site technical support, adjusting formulations as conditions changed. This optimized excavation, reduced clogging and downtime, and significantly improved efficiency.
As a result, the average daily rate of excavation increased from the typical 15 to 20 meters of new tunnel to a record 41 meters in 24 hours.
First Challenge
Construction of the continent’s deepest metro station, Itaberaba-Vila Penteado, at 66 meters and nearly twice the depth of the previous record holder.
Second Challenge
Changing soil-conditioning and back-filling needs during the excavation of a double-track tunnel in different types of terrain.
Third Challenge
Complex tunneling under building foundations, utilities infrastructure, metro lines, and the city’s biggest river.
Fourth Challenge
Impact of the dense urban environment and traffic restrictions on construction site logistics, including delivery times and product shelf life.
DURABILITY WITH LOWER ENVIRONMENTAL IMPACT
The tunnel boring machine places curved precast concrete segments behind it which are essential pieces to form the rings that line and reinforce the tunnel. A small gap forms between the soil and the concrete tunnel wall, which is filled with a special grout to keep the tunnel stable.
Sika Brazil developed a high-performance grout for the required compressive strength — cutting installation time and costs while lowering CO2 emissions.
41 meters
a new one-day tunneling record achieved with Sika solutions
10.6 meters
diameter of the tunnel boring machine’s cutting head
66 meters deep
new station sets a new record
First Sika Solution
Readily biodegradable foaming agents and polymers for soil conditioning
Second Sika Solution
Pre-excavation injections to stabilize the ground before the passage of the TBM
Third Sika Solution
High quality greases and lubricants for TBM main bearing protection and maintenance
Fourth Sika Solution
Tail sealant greases applied between the shield of the TBM and the external surface of the precast concrete tunnel lining to prevent water, excavated ground, and backfill grout from entering the TBM area
Fifth Sika Solution
Backfill grout injected in the annulus ring between the excavated ground and the tunnel lining, with a special emphasis in reducing cement content
Sixth Sika Solution
High-performance admixtures for precast concrete elements
BENEFITS ABOVE GROUND AND BEYOND
Independent studies showed that Sika soil-conditioning solutions kept the excavated soil within low-impact environmental parameters, making it safe to reuse or dispose of.
Sika teams in Lima (Peru), Santiago (Chile), and São Paulo (for Line 2) are now using the same range of soil-conditioning and backfilling grout solutions on their large-scale urban metro projects.
100+ years
lifespan
15.3 kilometer
double-track tunnel
Cutting
time, water use, CO2 emissions
FUTURE FOCUS
Sika has been a major project partner from the start, providing and although the University Line has yet to open, there are talks of extending it. Sika Brazil is already thinking about implementing new technologies that can accelerate project schedules and introduce other sustainability solutions, according to Michel Haddad, Target Market Manager at Sika Brazil.
The advantage of long-term planning is evident for the hundreds of thousands who will soon enjoy a 23-minute commute instead of spending 90 minutes on public transportation.
