Difference between revisions of "Geotextiles"

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(Created page with "<ul><li>Material specifications should conform to Ontario Provincial Standard Specification (OPSS) 1860 for Class II geotextile fabrics.</li> <li>Fabrics should be woven monof...")
 
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<p>Primary considerations are:
<p>Primary considerations are:
<ol>
<ol>
<li>Suitable apparent opening size (AOS) for non-woven fabrics, or percent open area (POA) for woven fabrics, to maintain water flow even with sediment and microbial film
build-up;</li>
<li>Maximum forces that will be exerted on the fabric (i.e., what tensile, tear and puncture strength ratings are required?);</li>
<li>Maximum forces that will be exerted on the fabric (i.e., what tensile, tear and puncture strength ratings are required?);</li>
<li>Load bearing ratio of the underlying native soil (i.e., is geotextile needed to prevent downward migration of aggregate into the native soil?);</li>
<li>Load bearing ratio of the underlying native soil (i.e. is the geotextile needed to prevent downward migration of aggregate into the native soil?);</li>
<li>Texture (i.e., grain size distribution) of the overlying aggregate material; and</li>
<li>Texture (i.e., grain size distribution) of the overlying fill material; and</li>
<li>Permeability of the native soil</li>
<li>Permeability of the native soil</li>
<li>Suitable apparent opening size (AOS) for non-woven fabrics, or percent open area (POA) for woven fabrics, to maintain water flow even with sediment and microbial film build-up;</li>
</ol>
</ol>
<table class="table table-bordered">
<caption>Recommended criteria for selection of geotextile fabric</caption>
<tr class="success"><th>Percent media passing 0.075 mm (#200 sieve)</th><th>Non-woven fabric apparent opening size (AOS, mm)</th><th>Woven fabric percent open area (POA, %)</th><th>Permittivity (sec<sup>-1</sup>)</th></tr>
  <tr><td align="center" valign="middle">>85</td><td align="center" valign="middle"rowspan = 2>≤ 0.3</td><td align="center" valign="middle">Not recommended</td><td align="center" valign="middle" rowspan = 2>0.1</td></tr>
  <tr><td align="center" valign="middle">50 - 85</td><td align="center" valign="middle" rowspan = 3>≥ 4</td></tr>
  <tr><td align="center" valign="middle">15 - 50</td><td align="center" valign="middle" rowspan = 3>≤ 0.6</td><td align="center" valign="middle">0.2</td></tr>
  <tr><td align="center" valign="middle">5 - 15</td><td align="center" valign="middle" rowspan =2>0.5</td></tr>
  <tr><td align="center" valign="middle">≤ 5</td><td align="center" valign="middle">≥ 10</td></tr>
  </table>
</p>
</p>

Revision as of 18:58, 4 July 2017

  • Material specifications should conform to Ontario Provincial Standard Specification (OPSS) 1860 for Class II geotextile fabrics.
  • Fabrics should be woven monofilament or non-woven needle punched. Woven slit film and non-woven heat bonded fabrics should not be used as they are prone to clogging.

Primary considerations are:

  1. Maximum forces that will be exerted on the fabric (i.e., what tensile, tear and puncture strength ratings are required?);
  2. Load bearing ratio of the underlying native soil (i.e. is the geotextile needed to prevent downward migration of aggregate into the native soil?);
  3. Texture (i.e., grain size distribution) of the overlying fill material; and
  4. Permeability of the native soil
  5. Suitable apparent opening size (AOS) for non-woven fabrics, or percent open area (POA) for woven fabrics, to maintain water flow even with sediment and microbial film build-up;
Recommended criteria for selection of geotextile fabric
Percent media passing 0.075 mm (#200 sieve)Non-woven fabric apparent opening size (AOS, mm)Woven fabric percent open area (POA, %)Permittivity (sec-1)
>85≤ 0.3Not recommended0.1
50 - 85≥ 4
15 - 50≤ 0.60.2
5 - 150.5
≤ 5≥ 10