Difference between revisions of "OPSS aggregates"

From LID SWM Planning and Design Guide
Jump to navigation Jump to search
 
Line 1: Line 1:
 
[[File:Aggregates Highway 7.jpg|thumb|The fines can clearly be seen on these piles of standard OPSS aggregates for road reconstruction]]
 
[[File:Aggregates Highway 7.jpg|thumb|The fines can clearly be seen on these piles of standard OPSS aggregates for road reconstruction]]
<onlyinclude>Of the standard granular materials in the standard [https://www.roadauthority.com/Standards/?id=a28fdfaf-3bf8-4679-81ca-4e44b2263cf8] only '''Granular O''' is recommended as a substitute for [[reservoir aggregate| clear stone]] in LID construction.  
+
<onlyinclude>Of the standard granular materials in the standard [https://www.roadauthority.com/Standards/?id=a28fdfaf-3bf8-4679-81ca-4e44b2263cf8 OPSS.PROV 1010] only '''Granular O''' is recommended as a substitute for [[reservoir aggregate| clear stone]] in LID construction.  
 
{{Textbox|1= Where Granular O is substituted for clear stone in underground reservoir structures, the porosity used in design calculations shall be '''0.3''' unless laboratory testing proves otherwise.}}
 
{{Textbox|1= Where Granular O is substituted for clear stone in underground reservoir structures, the porosity used in design calculations shall be '''0.3''' unless laboratory testing proves otherwise.}}
 
Examples of BMPs with underground reservoirs include [[Underdrains]], [[infiltration trenches]], [[permeable pavements]], [[infiltration chambers]], [[exfiltration trenches]].  
 
Examples of BMPs with underground reservoirs include [[Underdrains]], [[infiltration trenches]], [[permeable pavements]], [[infiltration chambers]], [[exfiltration trenches]].  

Latest revision as of 16:16, 1 December 2023

The fines can clearly be seen on these piles of standard OPSS aggregates for road reconstruction

Of the standard granular materials in the standard OPSS.PROV 1010 only Granular O is recommended as a substitute for clear stone in LID construction.

Where Granular O is substituted for clear stone in underground reservoir structures, the porosity used in design calculations shall be 0.3 unless laboratory testing proves otherwise.

Examples of BMPs with underground reservoirs include Underdrains, infiltration trenches, permeable pavements, infiltration chambers, exfiltration trenches.

All other mixes must be avoided for free drainage or storage as they are permitted to contain a higher enough proportion of fines to reduce permeability below 50 mm/hr.

Justification[edit]

Grain size analysis, percent passing[1] [2]
Sieve size (mm) A B type I B type II B type III M O (SSM)

Select Subgrade Materials

(OGDL)

Open Graded Drainage Layer

High Low High Low High Low High Low High Low High Low High Low High Low
150 100 100 100 100 100 100
106 100 100
37.5 100 100 100 100
26.5 100 100 50 100 50 100 50 100 95 100 50 100 100 95
19 85 100 100 100 80 95 100 90
13.2 65 90 75 95 60 80 86 40
9.5 50 73 32 100 55 80 50 70 55 20
4.75 35 55 20 100 20 55 20 90 35 55 20 45 20 100 10 0
1.18 15 40 10 100 10 40 10 60 15 40 0 15 10 100
0.3 5 22 2 65 5 22 2 35 5 22 5 95
0.15 15 2 65
0.075 2 8 0 8 0 10 0 8 2 8 0 5 0 25 2 0
d60 13 6 35 0.25 25 6 40 1.2 10 5 15 7 35 0.15 2 NaN
d10 0.7 0.1 1 0.08 1.2 0.075 1.2 0.085 0.6 0.09 2.5 0.3 1.2 NaN 0.658 0.466
Content Uniformity 19 60 35 3 21 80 33 14 17 56 6 23 29 3 NaN
Porosity (Vukovic) 0.26 0.26 0.40 0.26 0.26 0.26 0.27 0.26 0.27 0.26 0.34 0.26 0.26 0.40 0.25
Mean porosity (Vukovic) 0.26 0.33 0.26 0.26 0.26 0.3 0.26 0.38
K(Hazen)(mm/hr) 1764 36 3600 23 5184 20 5184 26 1296 29 22500 324 5184 NaN 62500
Mean K(hazen)(mm/hr) 900 1812 2602 2605 663 11412 NaN 62500

Porosity values were calculated based on the coefficient of uniformity (CU)[3][4][5]: Where coefficient of uniformity is the ratio of the 60th and 10th percentile grain sizes:

Permeability (K) was estimated from the 10th percentile grain size using the Hazen formula.

References[edit]

  1. OPSS. (2013). Material Specification for Aggregates - Base, Subbase, Select Subgrade, and Backfill Material. Retrieved from https://www.toronto.ca/wp-content/uploads/2017/11/91ba-ecs-specs-roadspecs-TS_1010_Sep2017.pdf
  2. OPSS. (2020). Construction Specification for Open Grades Drainage Layer. OPSS.PROV 320. Retrieved from: https://www.toronto.ca/wp-content/uploads/2017/11/91ba-ecs-specs-roadspecs-TS_1010_Sep2017.pdf
  3. Vuković, Milan and Soro, Andjelko Determination of hydraulic conductivity of porous media from grain-size composition. Water Resources Publications, Littleton, Colo, 1992.
  4. Odong, J. (2007). Evaluation of Empirical Formulae for Determination of Hydraulic Conductivity based on Grain-Size Analysis. Journal of American Science, 3(3). Retrieved from http://www.jofamericanscience.org/journals/am-sci/0303/10-0284-Odong-Evaluation-am.pdf
  5. Zhang, S. (2017). Relationship between Particle Size Distribution and Porosity in Dump Leaching. the University of British Columbia. Retrieved from https://open.library.ubc.ca/collections/ubctheses/24/items/1.0357233