Difference between revisions of "OPSS aggregates"

From LID SWM Planning and Design Guide
Jump to navigation Jump to search
m
m
Line 3: Line 3:
Examples of BMPs with underground reservoirs include [[Underdrains]], [[infiltration trenches]], [[permeable paving]], [[infiltration chambers]], [[exfiltration trenches]].  
Examples of BMPs with underground reservoirs include [[Underdrains]], [[infiltration trenches]], [[permeable paving]], [[infiltration chambers]], [[exfiltration trenches]].  


Particular care should be made to avoid any use of granular B type II or Select Subgrade Material (SSM). Both of these materials are permitted to have a higher proportion of fines in the distribution.  
Granular B type II and Select Subgrade Material (SSM) must be avoided in all LID structures. Both of these materials are permitted to have a higher proportion of undesirable fines in the distribution.  


===Justification===
===Justification===

Revision as of 18:47, 18 March 2018

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

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

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

Granular B type II and Select Subgrade Material (SSM) must be avoided in all LID structures. Both of these materials are permitted to have a higher proportion of undesirable fines in the distribution.

Justification[edit]

Grain size analysis, percent passing[1]
Sieve size (mm) A B type I B type II B type III M O SSM
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
26.5 100 100 50 100 50 100 50 100 95 100 50 100
19 85 100 100 100 80 95
13.2 65 90 75 95 60 80
9.5 50 73 32 100 55 80 50 70
4.75 35 55 20 100 20 55 20 90 35 55 20 45 20 100
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
d60 13 6 35 0.25 25 6 40 1.2 10 5 15 7 35 0.15
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 NN
Content Uniformity 19 60 35 3 21 80 33 14 17 56 6 23 29
Void ratio (Vukovic) 0.26 0.26 0.26 0.40 0.26 0.26 0.26 0.27 0.27 0.26 0.34 0.26 0.26
Mean void ratio (Vukovic) 0.26 0.33 0.26 0.26 0.26 0.3 0.26
K(Hazen)(mm/hr) 1764 36 3600 23.04 5184 20.25 5184 26.01 1296 29.16 22500 324 5184 NN
Mean K(hazen)(mm/hr) 900 1812 2602 2605 663 11412 NN

Void ratios were calculated based on the coefficient of uniformity (CU)[2][3][4]: 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.


  1. OPSS. (2013). Material Specficiation for Aggregates - Base, Subbase, Select Subgrade, and Backfill Material. Retrieved from http://www.raqsb.mto.gov.on.ca/techpubs/ops.nsf/0/0b9aa4d966cac4f9852580820062909e/$FILE/OPSS.MUNI%201010%20Nov%2013.pdf
  2. Vuković, Milan and Soro, Andjelko Determination of hydraulic conductivity of porous media from grain-size composition. Water Resources Publications, Littleton, Colo, 1992.
  3. 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
  4. 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