A lot can happen in two months and if you’ve been by the site recently, you know what I mean. Since my last post, 711 Breslay has transformed from a dirt lot into a full blown construction site with our team busy at work everywhere you look. Along Breslay Street, offsite civil work has now been finalized. This process involved laying and burying electrical conduit meant to house Hydro, Telus and Shaw cables. Burying these lines allows us to remove the overhead cables that currently clutter the streetscape – a detail that may seem a bit lackluster at first, but is always appreciated by our homeowners come moving day.
Excavation is now nearing completion and by the time all is said and done we will have moved nearly 17,500 cubic metres (or 1,750 truckloads) of dirt off the site. At its deepest, the parkade will sit 25 feet below grade. Built property line to property line, it will consists of 2 levels of underground parking, storage, and utility rooms. Building to the property line allows us to maximize the size of the parkade but creates a possible issue in terms of the stability of the perimeter walls. As you can imagine digging a 25,000 ft2 hole down 25 feet without proper bracing could cause a collapse of the exterior dirt walls. In order to eliminate this risk, we worked closely with our Geotechnical Engineer to develop a shoring design suited to the task.
The proposed solution was a combination of underpinning and pile shoring. The former makes use of 15-20 ft. steel rods drilled perpendicularly into the perimeter walls and reinforced with metal meshing and shotcrete (think: spray-on concrete). The latter, used in areas where we do not have access to the adjacent properties, consists of larger vertical piles (think: pipe) filled with concrete and then also covered with mesh and shotcrete. The installation was done in 5 sequences (think: levels) starting on the east wall and moving counter clockwise in a downwards spiral motion. This was necessary to ensure that the higher areas were properly secured before the deeper levels were tackled.
In addition to the underpinning and piling mentioned above, our Geotech’s proposal included an accompanying support system on the south side of our site. Due to the depth of this area as well as our inability to underpin the adjacent properties, further support was required to ensure that the piling was effective. The result was a sophisticated combination of angled struts and corner bracings, the installation of which was quite impressive to watch. These struts are required to stay in place until the parkade is fully built. In order to do this, block-outs will be used to circumvent the suspended slab which will allow construction to continue as planned (i.e. we will form the suspended slab around the angled struts and then once they are no longer needed, cut them out and fill the remaining void with concrete). This also happens to be the process that we will use for our crane, as it will sit right in the middle of our building as we build up.
After building Bloom (our last project across the street) we always knew there was a possibility that we would hit water. Our hope though was that the topography of the area (Novella sits at a higher elevation than Bloom) would work to our advantage and allow us to avoid the resident underground stream. During the last few feet of excavation it became clear that the deepest areas of the parkade (think: the elevator shaft, crane pad) were going for a swim. The stream, flowing at a rate of 80 to 100 gallons per minute, rendered all excavation efforts useless at these lower levels as the flowing water simply took the place of any removed dirt. This caused a headache or two (to say the least!) but the solution was a sump and pump system that successfully redirected the water, allowing our crew to finalize the preparations for the arrival of our crane.
Our Hammerhead crane (named after its shape) was delivered to the site in early November. It came in multiple pieces (7 to be exact), and took a full day to offload and install. It took another 2 days to test and ensure that everything was in working order. The crane’s operator cab sits roughly 125 ft. above ground, a job not for the faint of heart I’m told. Well…I’m not one to turn down a free climb up a 40m crane…so, challenge accepted! I plan to train over the holidays. Proof to follow in the New Year.
Happy holidays, everyone! ☃
Katelyn is the Development Manager at Springbank Properties. With degrees in finance and economics under her belt, she made the move out west in search of clearer waters, bigger mountains and to pursue her passion for real estate. She is an avid mountain biker, fervent foody and oversees all things related to this novella.