Changes

The following calculation is used to size the stone storage bed (reservoir) used as a base course for designs without underdrains. It is assumed that the footprint of the stone bed will be equal to the footprint of the pavement. The following equations are taken from the ICPI Manual <ref>Smith, D. 2006. Permeable Interlocking Concrete Pavements; Selection, Design,

The following calculation is used to size the stone storage bed (reservoir) used as a base course for designs without underdrains. It is assumed that the footprint of the stone bed will be equal to the footprint of the pavement. The following equations are taken from the ICPI Manual <ref>Smith, D. 2006. Permeable Interlocking Concrete Pavements; Selection, Design, Construction, Maintenance. 3rd Edition. Interlocking Concrete Pavement Institute. Burlington, ON.</ref>

Construction, Maintenance. 3rd Edition. Interlocking Concrete Pavement Institute.

Burlington, ON.</ref>

The equation for the depth of the stone bed is as follows:  

The equation for the depth of the stone bed is as follows:  

*''t'' = Time to fill stone bed (typically 2 hr)  

*''t'' = Time to fill stone bed (typically 2 hr)  

*''V_R'' = Void ratio for stone bed (typically 0.4 for 50 mm dia. [[reservoir aggregate|clear stone]])}}  

*''V_R'' = Void ratio for stone bed (typically 0.4 for 50 mm dia. [[reservoir aggregate|clear stone]])}}  

 

For designs that include an underdrain, the maximum depth of the stone reservoir below the invert of the underdrain pipe can be calculated as follows:  

For designs that include an underdrain, the maximum depth of the stone reservoir below the invert of the underdrain pipe can be calculated as follows:  

<math>d_{max} = \frac{f' \times t}{V_{R}}</math>  

<math>d_{max} = \frac{f' \times t}{V_{R}}</math>