Not Just a Pipe Dream November 2008
Pipeline buried under busy four-lane road offers unique route for concrete delivery during construction of 25 York Street office tower in downtown Toronto
STURTEVANT, WI (November 3, 2008) – As the first major office tower under construction in downtown Toronto in more than a decade, the $250 million 25 York Street project will soon be the most environmentally smart building in the city. It is also a showcase of innovative concrete placing ideas and advanced equipment technology put into action.
Although ready mix trucks are never seen lined up on the street adjacent to the construction project or cluttering up the job site, concrete is still being placed for the 30-story office building. That’s because far from the concrete pours, the ready mix trucks are discharging into a Putzmeister BSA 14000 HP-D trailer-mounted pump set up in a vacant parking lot across a busy four-lane road from the building site.
The high pressure trailer pump is using its powerful 630-horsepower (470kW) engine to pump concrete through pipeline strategically buried under the street. This innovative approach to routing concrete is an extremely unusual endeavor, as it required digging up an existing street to lay the pipeline or concrete delivery line. In turn, the concrete is traveling to a separate placing boom on the other side of the street, which is placing the concrete mix to complete the high rise on schedule for occupancy by its lead tenant, TELUS, a national telecommunications company in Canada.
Traffic Control The unique placing system arrangement is working with unbelievable success to make this pipe dream a reality. Collaborating in the ingenious plan are three Ontario-based companies – the project’s owner, developer and builder, Menkes Developments Ltd. of Toronto; the concrete contractor, Premform Ltd. of Brampton; and the concrete pumping contractor, Amherst Group of Scarborough. Credited for specifically masterminding the logistics are two individuals – John Neilson, CET, GSC and senior superintendent of Menkes Construction Ltd. and Paul Turney, equipment manager of Amherst Concrete Pumping.
“The setup was designed to facilitate better access to the job site, and is the first undertaking of its kind that I’ve ever seen,” says Neilson, who has 30 years experience supervising construction projects.
“Surrounded by the Air Canada Centre on the east, a railway line to the north and busy York Street, the logistics of the tight building site demanded that we do something different,” says Turney. “At first, most were skeptical about the idea of routing the delivery lines under the street; but once the plan was implemented, its benefits were soon realized.”
With the trailer pump and ready mix trucks remote from the building site, the major benefit is avoiding traffic issues on York Street. This extremely busy street is next to the building site and the only entrance into the Air Canada Centre, a sports and entertainment arena with a 12-story office tower. Additionally, the plan prevents congestion of the already overcrowded job site and frees up crane time for other trades.
“By using the parking lot on the west side of York Street as a staging area for the pump and ready mix trucks, we have better control over concrete delivery and can concentrate on pumping,” notes Turney.
Pipeline to Success “Pre-engineering is 90 percent of the work,” adds Neilson as he describes the time and energy involved in strategically working out the logistics of the unusual concept.
Numerous details needed attention and several calculations required verification, especially confirming the BSA 14000’s ability to pump concrete over a 750 feet (230m) distance to its final point of placement. However, once the equipment was witnessed in action at a nearby tunnel job site, confidence in the model was quickly gained, as the unit was easily pumping concrete 2,100 feet (640m), a distance about three times greater than needed for the tower.
Yet, once all the calculations were verified, another hurdle remained. Approvals from city officials for burying pipe under the street still had to be obtained. Fortunately, time and persistence paid off and the necessary permits were granted to install three concrete delivery lines under York Street.
The delivery lines were buried under the street while keeping a northbound and southbound traffic lane open at all times over a summer weekend in 2007. The procedure involved digging an open path across the street; laying and then burying the lines in concrete; and finally, repaving the road. Site services contractor, VIPE Construction Ltd. of Scarborough, Ontario accomplished the difficult and very unique task.
The three identical delivery lines, all five-inch (125mm) in diameter, include one main line to deliver the concrete to a 650 feet (200m) distance en route to the placing boom, while the second line serves as a backup and the third is a spare. As the major project requires a substantial amount of concrete due to its abundance of 12-inch (300mm) thick slabs, three lines offer a redundancy factor by taking into consideration unforeseen pipe wear.
Placing boom has all the right moves To smoothly place the concrete, a Putzmeister MXR 34/38Z separate placing boom is using its long 108' 7" (33.10m) horizontal reach for maximum coverage. The model also uses its Multi-Z boom to effectively articulate under the low clearance of an on site tower crane.
“Only the Multi-Z boom can maneuver its boom under the low overhead height of the working crane and still access the pour,” says Turney. “Other boom designs would require the crane to park out of the way during a concrete pour, which keeps the crane from functioning and consequently stops production for the other trades.”
From the ground up, the placing boom has been handling concrete placement for the 325-foot (100m) tall building, which includes a five-level podium and three levels of underground parking. In the early stages, the placing boom was flown between two Putzmeister pin towers to cover the massive foundation footprint.
“Flying the boom was a quick and easy process, as both placing boom towers feature a convenient four-pin connection,” says Turney. “The crew could simply disconnect, pick and move the entire system in under ten minutes with the on site crane. However, once the fifth floor was reached, only one placing boom tower was required; and it was modified to a hydraulic climbing system for raising the tower without a crane.”
“The equipment setup is working exceptionally well, while freeing up the crane to do other productive work,” says Tony DiNardo, general manager at Premform. “Plus, we’ve been able to improve efficiency, as Amherst is doing an exceptional job, making sure everything goes smoothly when placing concrete.”
Big boom pump steps up the pace With the project under a very targeted completion date, inclement weather in fall 2007 wreaked havoc with the schedule. To speed up the concrete placing process, Amherst scheduled the largest truck-mounted concrete boom pump from their fleet, a special BSF 63Z/61.20H, a first and only model of its kind, to simultaneously pump concrete with their 38Z-meter placing boom one November weekend.
The truck-mounted model extended its long boom a full 200 feet (61m) to reach the required distance while its .20H pump cell, capable of high volumes up to 260 cubic yards an hour (200m³/hr), helped achieve faster concrete placement.
Production in Motion The large commercial project is expected to consume approximately 65,500 cubic yards (55,000m³) of concrete dispatched by Toronto-based Innocon Lakeshore, a LaFarge company. The concrete producer is supplying the high strength, quick-setting mixes from 4,000 to 9,000 psi.
The BSA 14000 trailer pump, capable of high outputs up to 133 cubic yards an hour (102m³/hr) and maximum pressures up to 3,190 psi (220 bar), is quickly gulping down the concrete mix. As a result, it is only taking about five to six minutes to discharge a ready mix truck, with ample room to stage two mixers at a time for continuous pumping.
“We have a real production line going here,” says Turney, who believes the operation is saving the developer time and money. About 250 to 400 cubic yards (200 to 300m³) of concrete can be pumped during an eight-hour work day. Plus, with a recently accelerated schedule, the project has gone to two daily shifts, so the equipment is busy placing over 1,300 cubic yards (1000m³) a week.
“We’ve increased production around 30 to 40 percent,” says Neilson as he notes the success of the placing system arrangement. “The Putzmeister equipment has continually performed without any problems; and Amherst is number one with us, as they have been actively involved with the project from the start and continue to ensure that all logistics are handled.”
Amherst is no stranger to challenging projects like 25 York Street. With over 40 years experience placing concrete for commercial construction, road and bridge industries and home builders, they are presently tackling four other complex high rise projects in Toronto as well as an intricate tunnel construction job in Queenston.
To handle these complicated projects with greater efficiency, the company is relying on a knowledgeable team and the latest technological advances found on their equipment. Today, their state-of-the-art fleet includes a wide variety of truck-mounted concrete boom pumps, separate placing booms, trailer pumps and deck placers.
Going Green The 25 York Street landmark project, being developed by Menkes Union Tower Ltd., is a joint venture partnership between Toronto-based companies Menkes Developments Ltd. and Hospitals of Ontario Pension Plan (HOOPP) along with Boston, Massachusetts-based Halcyon Real Estate Partners Fund.
Toronto-based architects, Adamson Associates with support from Sweeney Sterling Finlayson & Company designed the 780,000 square feet (72,500m²) tower, which will establish a new standard for environmental responsibility and energy efficiency for Toronto office buildings. This will be accomplished by pursuing Gold status for new construction under Leadership in Energy and Environmental Design (LEED) criteria.
The downtown site, amid a presently upbeat Toronto economy, was also chosen for other “green” reasons. It promotes the continued development of the waterfront and offers multiple convenient and regularly serviced public transit options. As an example, the new tower’s expansive 30-foot (9m) high lobby will link directly to the PATH system, Union Station and the Air Canada Centre.
An Expanding Skyline The office tower broke ground in September 2006. Today, against the backdrop of the CN Tower, Canada's most recognizable icon and another landmark project pumped by Amherst, 25 York Street is rising to the sky. Occupancy is scheduled for summer 2009 when 60 percent of the building will be occupied by TELUS.