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HomeMy WebLinkAboutF_Snow Storage Report 06-30-2020memo Page 1 TO: Matt Ekstrom, PE FROM: Celine Saucier, PE DATE: March 18, 2019 JOB NO.: 3959.022 RE: Bozeman East Apartments – Snow Storage CC: Urgent For Review Please Comment Please Reply For Your Use This memo presents technical data for the snow storage plan at the Bozeman East Apartment complex. The following design parameters were used to develop a snow storage plan: · A snow depth of 2 feet across the asphalt parking area for a snow volume. · Snow storage piles may be stacked maximum 8 feet high, with 2:1 side slopes. · 168,536 sq. ft. of parking area (this is the total asphalt area, including drive aisles and parking stalls) that will require snow removal into storage piles. · The (18) proposed snow storage piles will have a total area of 136,404 sq. ft. (Table 1). In addition to the City of Bozeman recommendations, an in-house analysis was conducted to arrive at a “compaction factor.” The compaction factor is to try and approximate the percent compaction the snow receives as plows remove it from its original state. On January 30, 2018, Bozeman, MT received several inches of new snow as temperatures dipped into the teens overnight. The following day, measurements were taken of the weight of loosely placed snow in an empty 6” x 12” cylinder. The weight of compacted snow was also recorded, and done so by placing (3) lifts of loose snow and compacting each lift. It was observed by (3) separate trials that loose snow was approximately 40% the weight of the well-compacted snow in this controlled environment. Thus, it was concluded that loose snow compacts to about 40% of its original volume, or the compaction factor is approximately 60%. Using a snow depth of 2 feet across the asphalt area, it is anticipated that 337,072 cubic feet of snow will need to be removed. Using the aforementioned compaction factor of 60%, this volume reduces to 134,829 cubic feet (required snow storage volume). Bozeman East Apartments – Snow Storage Page 2 Table 1 below summarizes how this volume of removed snow will easily be stored in the (18) trapezoidal-shaped snow storage piles that can be seen on attached Exhibit 1. Storage piles are located clear of landscaping, public right-of-ways, and outside of vision triangles. Pile Number Avg. Width (ft.) Area (sq. ft.) Available Volume (cubic ft.) 1 20 972 6221 2 12 291 1552 3 10 167 802 4 11 207 1054 5 12 291 1552 6 11 263 1339 7 11 392 1996 8 16 474 2844 9 21 587 3802 10 10 245 1176 11 19 1758 11103 12 12 195 1040 13 40 2450 17640 14 13 483 2675 15 12 207 1104 16 13 483 2675 17 12 203 1083 18 83 10079 76746 Totals 19747 136404 *Volume calculation based on trapezoidal shape Table 1: Snow Storage Volume Calculation As shown in Table 1, the available snow storage volume of 136,402 cubic feet is adequate to accommodate the required storage volume of 134,829 cubic feet. This design approach is a conservative estimate of how much snow storage volume is required because it does not implement other obvious factors that will affect snow storage volume. Storage piles will inevitably be subject to freezing and thawing cycles. During these cycles, storage piles will be reduced by percolation and evaporation. This factor was not considered in our required volume calculations. The available snow storage volume will also be affected due to vehicles in the parking area prohibiting the removal of all the snow, therefore snow storage behind parking stalls has been eliminated. Instead, the storm detention pond will have a gate and armored path that allows for the snow plow to store a large volume of snow as shown in pile #18. PSD SD SD SD SD SD SD SD SDSDSDSDSDSDSDSDWWWWWWSAN MHRIM=4729.31INV N=4717.92INV SE=4718.02SDSDW SDP PSDSD SD SD SD SDSAN MHRIM=4731.18INV S=4720.48INV W=4720.40SAN MHRIM=4732.18INV NW=4719.87INV E=4719.90SAN MHRIM=4724.99INV N=4715.61INV E=4715.59INV S=4715.51INV W=4715.48SAN MHRIM=4728.76INV N=4716.76INV S=4716.86PWV WV DYHWV WVPPDYHDYHP PDYHWVWVWV WVWVWV WV WVWV WV WV PPWWWWWWWWWWWWWW SSSSSSSS SS SS SS SS SSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSNGNGNGNGNGNGBPBPBPBPBPBPBPBFBFBFBFBTBTBTBCTVBCTVBCTVBCTVBCTVBCTVBCTVBCTVBCTVBCTVBCTVBCTVBCTVBCTVBCTVBCTVBCTVBCTVBCTVBCTVBCTVBCTVBCTVBCTV BCTVBCTV BCTVSDSDSDN87° 39' 57.09"W152.020EEE EEEPSD SD SD SD SD SD SD SD SDSDSDSDSDSDSDSDWWWWWWSAN MHRIM=4729.31INV N=4717.92INV SE=4718.02SDSDW SDP PSDSD SD SD SD SDSAN MHRIM=4731.18INV S=4720.48INV W=4720.40SAN MHRIM=4732.18INV NW=4719.87INV E=4719.90SAN MHRIM=4724.99INV N=4715.61INV E=4715.59INV S=4715.51INV W=4715.48SAN MHRIM=4728.76INV N=4716.76INV S=4716.86PWV WV DYHWV WVPPDYHDYHP PDYHWVWVWV WVWVWV WV WVWV WV WV PPWWWWWWWWWWWWWW SSSSSSSS SS SS SS SS SSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSNGNGNGNGNGNGBPBPBPBPBPBPBPBFBFBFBFBTBTBTBCTVBCTVBCTVBCTVBCTVBCTVBCTVBCTVBCTVBCTVBCTVBCTVBCTVBCTVBCTVBCTVBCTVBCTVBCTVBCTVBCTVBCTVBCTVBCTV BCTVBCTV BCTVSDSDSDN87° 39' 57.09"W152.020116112356710948121314151718©2880 Technology Blvd. W.Bozeman, MT 59718Phone: (406) 587-0721Fax: (406) 922-6702SHEET NUMBERPROJECT NUMBERDRAWING NUMBERDRAWN BY:CHK'D. BY:APPR. BY:DATE:Q.A. REVIEWDATE:BY:COPYRIGHT MORRISON-MAIERLE, INC.,2020VERIFY SCALE!THESE PRINTS MAY BEREDUCED. LINE BELOWMEASURES ONE INCH ONORIGINAL DRAWING. MODIFY SCALE ACCORDINGLY!REVISIONSDATEDESCRIPTIONNO.BYN:\3959\022\ACAD\Exhibits\Snow Storage\Snow Storage Exhibit.dwg Plotted by celine saucier on May/11/2020engineerssurveyorsplannersscientists3959.022EX-1BOZEMANMONTANATJWMEE03/2019SNOW STORAGE EXHIBITBOZEMAN EAST - APARTMENTSTSCHACHE LANEBUILDING4/DBUILDING1/ABUILDING2/BBUILDING3/C11x17 HORIZONTAL SCALE: 1" = 100'GRAPHIC SCALE0(IN FEET)255025501 INCH = 50 FTSNOW STORAGEPROPOSED SNOW STORAGE PILESAREA CONSIDERED FOR SNOW STORAGENOTE:PARKING STALLS WITHOUT HATCHING HAVE CARPORTS ANDARE EXCLUDED FROM THE CONSIDERED SNOW STORAGE AREAVISION TRIANGLES