Innovative Boom Design Pumps Toronto Subway
Pumping in congested urban conditions, longtime ACPA member Pumpcrete, Niagara Falls, Ontario, is executing multiple pours per day to speed construction of the Toronto-York Spadina Subway Extension project. The company is using its extensive arsenal of Schwing pumping equipment to execute pours in tunnels and in excavated portions of the 8.6 km long project which includes multiple stations for commuters. Pumpcrete’s concrete pump fleet includes the first-of-its-type boom design used in North America – The S 43 SX truck-mounted concrete pump with RZ five-section placing boom.
Working under general contractors Bondfield Construction, Concord, Ont., Pumpcrete is dispatching pumps daily on the project from their Toronto yard, according to Sam Meli, Pumpcrete sales representative, “In addition to performing cut and cover work every day we are placing the invert slabs in the south tunnel, as well as structural work for the Finch West station.” The company has extensive experience placing concrete inside tunnel bores. Their work with a massive diversion tunnel on the nearby Niagara River included pumping concrete more than 1.7 km for tunnel lining using an SP 8800 Schwing stationary pump (Concrete Pumping Magazine, Spring 2012 Edition).
More than 10 km of tunnel invert for the subway project is being pumped by another of their SP 8800s. “We have more than 10,000 cubic meters to be placed in the south tunnel, “ according to Meli, “The invert mix is higher strength than the walls and column mix and the SP 8800 has pushed it out to 2,700-feet so far with no problems.” The stationary pump is located on grade for ready-mix access with five-inch pipeline reaching to the pour area.
“The majority of our boom work is handled by our S 61 SX and S 58 SX Schwings, “ according to Meli, “We are pumping walls, columns and raft slabs averaging 1,000 to 1,200 yards per pour.” The Schwing long booms with reach to 197-feet utilize Overhead Roll and Fold boom designs which are engineered with all four boom sections articulating towards the pour area, allowing for maximum coverage. These models also utilize the Super X outriggers that allow for fast and compact set-up with their telescopic action and curved design. This combination of boom and outriggers also allow for fast moves, critical on cut and cover tunnel projects.
Another high utilization pump on the project has been Pumpcrete’s latest acquisition, the Schwing S 43 SX. “We were thrilled to be the first company in North America to work with the five-section RZ 5 boom, “ according to Dave Moriarty, Pumpcrete manager. With more than 900-degrees of boom articulations, all directed at the pour area, the S 43 SX offers more practical positions than other boom styles. “Plus the five sections allows a lot of boom reach (138’9”) on a relatively short chassis,” Moriarty states, “The Schwing 42-meter was a very popular machine in Canada and the S 43 SX is a worthy replacement.” The pump also features the Super X outriggers made popular on Schwing’s longer booms.
“We appreciate that our newest pump shares the same pumpkit as our larger pumps, “ according to Moriarty, “Besides parts standardization, a project like this requires the ability to pump a wide range of mixes, which the Generation III 2525H-6 pumping system does very well with the Big Rock sequencing valve and full five-inch boom pipe. The slow stroking action with large diameter cylinders allows our operators to provide smooth, steady flow for wall pours or flat-out 200 plus meters per hour for slabs.”
Pumpcrete has chosen to assign one operator to the new five-section boom. “He has the ability to maneuver the boom into some very tight situations using the 270-degree tip section,” according to Moriarty, “Because the excavations cannot be braced with tiebacks because of surrounding buildings, the cuts have struts across them to prevent cave-ins. The articulation of the Z Fold tip section is very useful when combined with the Roll and Fold third and fourth sections, which allow us to boom over the struts.”
With an unfolding height of only 28’4” the RZ5 boom has proven useful indoors for Pumpcrete allowing more utilization. “Industrial work and warehouse slabs are a big business for us and this boom handles them between pours on the subway project,” Moriarty stated. Shuttling between jobs on the four axle chassis is no problem. An inexpensive annual permit is all that is required for operation in the city.
More than 80,000 cubic meters will be consumed in the construction of the underground Finch West Station. “We are executing multiple pours per week with columns and walls consuming 100 to 150 cubic meters per pour,” according to Meli, “The wall mix utilizes a super plasticizer and is being pumped at 150 to 200 millimeter slump. Strengths run from 4,000 to 7,000 psi. A 400-space parking lot will also be built at the Finch West location to accommodate commuters for the trains that will run every four minutes. Estimated completion of the $127.5 million contract is expected by 2015.
“Because of our proximity to the site, dispatching has been very convenient for us, “ according to Moriarty, “With our wide range of equipment, we can easily handle any pumping situation on the job. Our decision to buy the S 43 SX was validated by its high usage on the project in many different pumping scenarios. We felt so strongly about its versatility we bought a second one at the most recent World of Concrete.”
The Toronto Subway and RT is a rapid transit system consisting of both underground and elevated railway lines, operated by the Toronto Transit Commission. It was Canada’s first completed subway system opened in 1954 with 12 stations. Since then, the system has expanded to become Canada’s largest and busiest rapid transit rail network. The Subway and RT encompass four lines and 69 stations on 68.3 kilometers (42.4 mi) of track, with six more stations and 8.6 kilometers (5.3 mi) scheduled to open in Fall 2016. The subway system is a very popular mode of public transport in Toronto, with an average of 1,054,200 passenger trips each weekday.
Owner: Toronto Transit Commission, Toronto, Ontario, Canada
General Contractor: Bondfield Construction, Concord, Ontario, Canada
Concrete Placing Contractor: Pumpcrete, Niagara Falls, Ontario, Canada
Equipment: Schwing SP 8800 stationary pump, Schwing S 61 SX S, S 58 SX and S 43 SX truck-mounted concrete pumps with placing booms