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78 | A PR IL 2017 Delta Secondary School Seismic Upgrade RENDERINGS COURTESY DELTA SCHOOL DISTRICT #37 Delta Secondary School Seismic Upgrade by ROBIN BRUNET I magine a major earthquake occurring in the vicinity of a school that is sitting largely on unconnected piles in a liquefiable soils zone. In addition to the expected calamity, the dynamics of the movement could cause the foundations to move in an unpredictable manner, likely causing significant damage and potential fatalities. That is one of the many reasons the Ministry of Education gave the go-ahead in 2015 to a $17.6-million seismic upgrade and $2.5-million building envelope upgrade of Delta Secondary School, one of the final two public schools in Delta that Victoria had identified as being at high risk of damage (152 such facilities had been identified out of 500 B.C. schools under the Seismic Mitigation Program). Seven public schools in Delta had received structural seismic upgrades previously. But even though the focus was to provide structural integrity to Delta Secondary, which had undergone numerous additions and reconfigurations over the decades, Delta School District #37 along with the collaborative team of Ausenco Engineering Canada Inc., Unitech Construction Management Ltd., Craven Huston Powers Architects (CHPA), Rocky Point Engineering Ltd. and McCuaig & Associates Engineering Ltd., also found ways to incorporate a building envelope program for the school's Genesis Theatre and perform cosmetic improvements. Frank Geyer, director of facilities and planning for Delta School District #37, describes Delta Secondary prior to the upgrading. "The site itself is over 100 years old with the current oldest wing dating back to the early 1960s. Since then, the school had undergone 13 different additions, removals and reconfigurations of varying structural and architectural design. No block matched the next in construction, interior finishes were of different vintages and the extent of work needed to bring the overall structure into the 21st century was extensive." Jeff Peters, project manager for Unitech, adds: "About three-quarters of the entire school rested on unconnected piles that went about 50 feet through highly unstable peat bog to a firmer footing. It could be said that the school was literally floating, and this was a major concern as none of the pile caps had been joined together." Peters stresses that "none of the deficiencies found in Delta Secondary was a result of substandard planning or construction; instead, we were merely confronting what were the standards of a past era." The full scope of work included upgrades to the theatre, automotive and woodworking shops, and art/ classroom blocks, including remedial work to adjacent blocks' foundations; partial demolition, renovations and non-structural seismic upgrades to the entire facility. Three areas of specific focus were the theatre, music and associated rooms; the woodwork/ automotive shops; and the two-storey learning assistance centre, classrooms, mechanical and electrical rooms. Due to the extensive seismic work required, Ausenco Engineering Canada Inc. was chosen as the prime consultant for the project, but John Sherstobitoff, principal, seismic and structures for Ausenco, stresses that "the success of this project depended on close collaboration with all parties right from the beginning of the project, since part of the task was to determine what elements of the upgrades could be performed during the school season and what could be delegated to the summer months. Reaching the pile caps and foundations required digging up corridors, tearing apart larger structures such as the theatre interior and accessing crawlspaces." Sherstobitoff uses layman's terms to describe the team's approach to connecting the piles. "If you take a single building from a bird's-eye view, the way to prevent pile caps at the perimeter of the building from moving outward due to liquefied soil would be to connect and contain them within a reinforced concrete and rebar frame," he says. "Since Delta Secondary is comprised of so many additions, we had to create multiple frames – some of them overlapping, some not." Crucial to the success of this approach was having access to reliable drawings, and Sherstobitoff says "fortunately we had a good set of drawings for the entire school, with everything for the most part indeed being at the location indicated in them." "As with any type of upgrade there were surprises, but nothing major. For example, we came across an old disused gas line and an oil tank, the latter of which was from the days when the portion of the school we were excavating was a parking lot," adds Peters. As to exactly how much concrete and rebar was required to secure the piles, Peters says: "Put it this way, the core of the school required 270,000 pounds of large-gauge rebar, a total of 782,000 pounds of rebar has been used, along with over 3,550 cubic metres of concrete." Non-structural seismic upgrades included restraint to ceilings, lighting, HVAC and sprinklers, as well as the installation of an earthquake early warning system. Electrical cabling retrofits were also required. It was eventually determined that sections of an interim cladding system of the Genesis Theatre (earlier installed to mitigate failure of the original face- sealed stucco cladding system) would need to be removed in order to permit extension of new structural steel framing up the outside of the theatre fly tower. "Delta already had an envelope upgrade in the hopper, so we proposed to dovetail it into our seismic work to save money," says Geyer. "The education ministry agreed, and we went ahead and installed a new rainscreen system and cladding in 2016." Because so much of the theatre interior had to be cut apart to access the piles underneath, CHPA was able to design a new stage and other elements. "The old stage was pretty worn out, so this was a bonus," says Geyer. Additionally, the structurally questionable (and, according to team members, downright ugly) 400-square-metre arts wing portion of Delta Secondary, built in 1982, was demolished, thus saving more money that could go towards modernization elsewhere in the school. Geyer credits Craven Huston for "designing new floor and wall finishes, a new entrance and a colour scheme that gives Delta a visual uniformity it previously never had." Plus, "using Annual Facility Grant funding and incentive grants from BC Hydro, we undertook a major energy conservation retrofit and installed LED lighting in the corridors, shops, library, theatre and a number of exterior locations." Geyer concludes that the most remarkable aspect is the fact that, "We did everything in two years. Now, not only are our students safe for the expected earthquake, we'll also be able to get more bookings for our theatre and gyms, and we have a good curb appeal – as well as a facility that will last at least another 50 years." A LOCATION 4615 – 51st Street, Delta, B.C. OWNER/DEVELOPER Delta School District #37 PRIME/STRUCTURAL/ SEISMIC CONSULTANT Ausenco Engineering Canada Inc. ARCHITECT Craven Huston Powers Architects (CHPA) GENERAL CONTRACTOR Unitech Construction Management Ltd. MECHANICAL CONSULTANT Rocky Point Engineering Ltd. BUILDING ENVELOPE CONSULTANT McCuaig & Associates Engineering Ltd. TOTAL SIZE 18,754 square metres TOTAL COST $17.6 million (seismic upgrade) $2.5 million (building envelope upgrade)

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