egsa,
Good post except for the comment that geotextiles are not considered reinforcement. This is completely false. The highest strength geosyntehtic reinforcement on the market are geotextiles (less open area means more strength) and are used for reinforcement applications.
Nonwoven...
Uniaxial geogrids have strength in 1 direction, typically the Machine Direction (MD) or the long direction of the roll. The reinforcement must be place perpendicular to the face because that is the direction of the strain in a reinforced wall, it is a 2-dimensional system. Unfortunately...
It is a leveling pad not a footing. They are flexible systems, why put them on a rigid "footing"?
Concrete causes a constructability issue too. An uneven concrete surface can cause leveling issues when setting the blocks.
NCMA allows the use of a concrete leveling pad, but not sure why you...
MSE with steel or geosynthetic reinforcement?
MSE with steel reinforcement installed price can range from $40 - $90/sf, to maybe as high as $125 like "3Fan" said. Prices are very dependant on project location, size, etc.
A MSE with geosynthetic reinforcement can range from $20 - $40/sf of face...
The R-value needs to be determined for the saturated sample, especially for a clay material. The properties of the clay will be very different depending on moisture content. Many times the subgrade soil is only evaluated at the in-situ moisture content at the time of evaluation. The problem...
It is funny that you call the Montana study junk but then post a paper from Tensar. The geotextile material used in the Tensar paper is not a high strength geotextile. Geotextile ultimate strength of the 1 geotextile used was 40 kN/m, that is low to moderate strength material. Also, looking...
It is good to have this type of thread to get some of these myths and marketing “stories” out into the open. Very interesting comments, and my friend 'theanimal1999' has only reinforced the misconceptions about geosynthetics.
In theanimal1999’s post to begin this thread, he indicates in...
What test method are you using to test tensile strength? I ask because you are showing units as kN, for geogrid testing the proper test would be a wide-width test that would give you kN/m values (ASTM D6637). 21 kN at 2% strain does not sound right for a biaxial geogrid.
Also, are both...
Need a little more info......
For MSE walls: Geosynthetic reinforced block walls are typically $18-$28 per square foot of face. Metal reinforcement concrete panel walls are typically $35-$65/sf of face.
If it is a temporary structure (less than 3 years) you can build a temporary geosyntethic...
It is a gravity wall system, so a stability analysis should tell you if the resisting force of the weight of the blocks is sufficient to resist the driving forces of the lateral earth pressure of the soil behind the wall plus any loads, ie structrue, traffic, construction, other.
That being...
Once in the ground, geosynthetics (geotextiles & geogrids) will last pretty much forever, as long as the soil is not biologically or chemically contaminated. As previously stated, all geosynthetics are suspect to UV degradation. Industry standards recommend geosynthetics be covered with soil...
Riggly,
Sorry for the slow reply, I do not check this board very often.
Yes, a geotextile can be used, and often should be used instead of a geogrid. By definition, when you are looking a subgrade stabilization, the subgrade soil is soft, with a CBR<3. In these instances you want to use all...
OldGeoGuy,
Thanks for setting the record straight. I too was ASTONISHED at the lack of knowledge of geosynthetics. Of course most of this comes from the slick marketing of some of the geosynthetic companies. One in particular that only makes geogrids will tell you that only geogrids have...
