2018-11-1_PR Comm Packet - Laserfiche WebLink

Home

The damage to date has been primarily limited to the expansion joints at the two southerly corners where the heave impacts the quality of the ice during the skating season and where any residual heave in the summer can complicate inline skating activity. To date, the heaved areas of the rink have primarily returned to their original elevation in the summer months and have allowed most programmed inline skating activity to occur. Without making improvements to restore good perimeter pavement drainage, heaving will continue to become worse and at some point, be detrimental to both winter and summer skating use. We strongly recommend perimeter drainage improvement be prioritized and be included in any initial improvements considered for the facility. Perimeter pavement and turf will need to be reconstructed if the grade beam and expansion-joint improvements recommended above are pursued. Perimeter Drainage System The perimeter drainage system consists of shallow-bury piping systems and catch basins. Much of this area has been subject to frost heave over the years and while the system still moves water we are not sure of the integrity of the piping. According to City operations staff, the piping seems to work but sometimes water can be seen standing in the catch basins. Televising the piping would help to better understand the integrity of the pipe and provide further information to establish the appropriate level of reconstruction needed to maintain positive drainage. We recommend the perimeter drainage system be reconstructed as part of any future improvement to the facility and particularly if the grade beam and expansion joint improvements described above are pursued. Televising the piping is not essential but would be helpful information for any redesign and reconstruction of the system. Underdrain System The underdrain system is primarily located under the refrigerated ice slab. An extensive array of 4” and 8” perforated tile is installed in the granular base beneath the slab. The 4” piping grid is arranged at 20 feet on center spacing in an east-west alignment (perpendicular to the long direction of the oval). The 4” piping terminates into an 8” perimeter drain which circles the rink alignment. The 8” perforated tile is connected into the gravity storm sewer system that flows into the storm pond just west of the oval. The underdrain system was designed to keep the subsoils beneath the rink slab dry. It appears the system is doing its job in most conditions from our discussions with City staff. As mentioned earlier in the report, it appears that the system is not capable of removing an excessive amount of subsurface water, particularly when a large amount of surface water quickly infiltrates under the slab from the perimeter of the rink. This excess water condition is most notably observed when surface water from winter snowmelt or rains enters the rink slab subsoils along the south end of the bandy slab and results in heaving of the bandy slab adjacent to this area. We feel this problem will be eliminated if a perimeter grade beam and expansion joint is installed around the entire rink slab and the adjacent areas are regraded to establish positive drainage away from the slab. We do not feel the underdrain system needs repair; however some enhancements to the system at critical areas could be considered with the improvements recommended in the report. Perimeter Fence The perimeter fence was designed to accommodate some movement from slab expansion and contraction. Over the years the stresses have had some impact on the fence alignment. Currently some of the fence has lost its vertical alignment. If the perimeter grade beam and expansion joint is installed, 202020