To reduce impact to parking and downtown businesses, construction on the Main Improvements Project will be completed in 5 stages. Construction will start at the intersection of Main Street (50 Avenue) and Highway 2A, then work along Main Street west to 53 Street, as well as 49C Avenue. The sequence of construction within each stage is generally as follows:
Construction signage and barricades are placed around the whole project area in preparation for short term, rolling road closures. Milling machines are in high demand throughout the summer so milling the whole project area at once is efficient and cost effective. The milling process on Main Street and 49C Avenue will take approximately 2-3 days to complete. Since the milled road will be approximately 100mm lower than the existing asphalt, smooth tapers are placed at intersections and crossings. Once complete, temporary line markings will be painted. Milling machines grind old asphalt into a recycled asphalt product that manufacturers use to make more asphalt, and the City will use as the Main Street and 49C Avenue, temporary road surface.
Long Term Road Closure
Construction signage and barricades are placed around the stage area. Vehicle turnarounds are established at streets that temporarily “dead-ended” because of construction on 50 Avenue or 49C Avenue. New parking signs are installed to direct motorists to nearby public parking lots. Crews install construction fencing at the sidewalks around the perimeter of each stage area, allowing for pedestrian crossing as shown on the staging maps. The sidewalks remain open and business access is unaffected. Road closures are estimated to be in effect for the duration shown on the stage maps.
Crews safely remove all the asphalt, roads signs, street lights and concrete curb/gutter from within the stage area. The trees on 49C Avenue remain in place and are protected during construction. Water trucks are used to minimize dust. Waste material is hauled offsite, and material to be reused is salvaged. Sidewalks remain open and business access is unaffected.
Sanitary Main Replacement and Road Core
A deep trench is carefully excavated to expose and replace the sanitary main. Skilled crews have to be diligent in monitoring the risk of damage to other utilities buried in the road (i.e. power/communications lines, gas lines, water/storm main, and water/sanitary/storm services). Much work has been completed in advance of construction to significantly reduce the risk of damage to other buried utilities.
As Main Street contains many more buried utilities and services on the east end of the project area compared to the west end, weekly production is expected to improve when crews are west of 52 Street. Upon completion of the underground replacements, the full road will be cored and replaced with uniform base material to mitigate the risk of road damage from the freeze/thaw cycle.
To significantly reduce the risk of vibration damage to adjacent buildings, the trench will be back-filled with sand and compacted using heavy static compaction equipment, instead of the usual heavy vibratory compaction equipment. Sanitary services to each building will be replaced in the same manner after the main pipe is installed. Drainage will be managed within each staged area. Once this work is complete within one stage area, crews will advance to the next stage, starting the construction sequence again with the long-term road closure. Water trucks are used to minimize dust. Sidewalks remain open and business access is unaffected.
Concrete Installation & Replacement
The concrete sidewalk replacement crew begins work after the sanitary main replacement crew advances to the next stage. In order to ensure that access to businesses is maintained, the concrete replacement crew first constructs the new curb/gutter and half of the new sidewalk closest to the road. The pedestrian bulb-outs, realignment of the 52 Street intersection, new access to the parking areas, and the new turnaround at the south end of 49 Street is evident at this point. The remaining half of the sidewalk is then installed, leaving the existing concrete intact directly in front of business doors.
In coordination with the City and its general contractor, a representative of the concrete crew meets with individual business owners/managers to schedule sidewalk replacements directly in front of their business. Light vibratory equipment is used to prepare the sidewalk base. Water trucks are used to minimize dust. Sidewalks remain open and business access is unaffected.
Once this work is complete within the stage area, crews will advance to the next stage to repeat the concrete installation and replacement process.
Landscaping, Street lights, and Signage
Landscape crews install new signage, plantings and limited new trees, benches, bike racks, and trash/recycling receptacles. Fortis Alberta crews arrive to install the new streetlights. Landscaping and streetlight crews arrive later in the project, when sufficient new concrete is complete to keep them on-site through to project completion. Water trucks are used to minimize dust. Sidewalks remain open and business access is unaffected.
Temporary road open
Once the new concrete curb and gutter is complete, preparations are made to temporarily open the road to traffic. A temporary inverted crown is constructed in the roadway to manage drainage, and the salvaged recycled asphalt product (millings) is placed as a temporary road surface. Construction fencing and redundant construction signage is removed. The road at this point is open to motorists and appears to have narrowed but this optical illusion is dispelled when the final road profile is shaped. Water trucks are used to minimize dust. Sidewalks will remain open and business access is unaffected.
Final Road Construction and Temporary Markings
Construction signage and barricades are placed around the whole project area in preparation for short-term, rolling road closures. Road crews prepare the road base to its final profile and pave the bottom and middle lifts of asphalt. Road crews are in high demand throughout the summer so this portion may be done in whole or part (half the project at a time) depending on construction progress and impact to businesses. Once complete, temporary line markings are painted. This concludes the 2017 work.
Final Asphalt and final road markings (2018)
Construction signage and barricades are placed around the whole project area in preparation for short-term, rolling road closures. Deficiencies such as trench settlement that may become apparent are corrected prior to the placement of the final lift of asphalt. The top and final lift of asphalt is placed and permanent line markings installed. Paving and line marking are estimated to take approximately 3-5 days to complete.