Another Retaining Wall Question - Landscaping & Lawn Care - DIY Chatroom Home Improvement Forum

Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > Landscaping & Lawn Care


Thread Tools Display Modes
Old 08-04-2010, 06:33 PM   #1
Join Date: Aug 2010
Posts: 1
Rewards Points: 10

Another retaining wall question


I am looking at doing a versa-lok wall that will be 3ft high. I believe I interpreted their documentation to say that I don't need geogrid because the height is only 3 ft.

What it isn't clear about is what if behind the wall is a pretty steep and deep slope? The hill behind it is probably close to 45 degrees and runs for about 30 ft back. Assuming favorable soil conditions, do I need geogrid? All of their illustrations show a nice level area behind the wall.


slopes is offline   Reply With Quote
Old 08-04-2010, 06:57 PM   #2
Join Date: Jul 2010
Posts: 36
Rewards Points: 25


In regards to Versa-Loks wall diagram on low walls, its safe to build what is refered to a gravity wall up to four feet in height with complete granular backfill.

That's if there is very little sur-charge behind the wall and that it is level in front of the wall.

Under your conditions, with the slope that you discribed, it would be best to put a layer of grid half way up the wall. Best grid to use for your conditions is a bio-directional grid, that are usually 4' wide by 50' lengths.

The grid will actually stabilize the soils behind the wall, thus creating a minature failure plain, instead of a large failure plain pushing on the base of the wall. Hope this helps.

Soil Identification & Sub-Grade Prep


Last edited by Kurtzilla; 08-04-2010 at 06:59 PM. Reason: miss spelling
Kurtzilla is offline   Reply With Quote
The Following 2 Users Say Thank You to Kurtzilla For This Useful Post:
concretemasonry (08-04-2010), slopes (08-04-2010)
Old 08-04-2010, 08:49 PM   #3
Civil Engineer
Join Date: Mar 2009
Location: Boston
Posts: 5,687
Rewards Points: 4,954

The Versalok block wall is rated for local stability to approximately 4 feet tall without geogrid, assuming adequate drainage and granular backfill, and a moderate slope behind the wall. Your problem is much more complex, since you may have a global stability problem.

A global stability problem essentially means the entire slope can come down. Should this occur, the slope failure will take the entire slope with it, Versalok wall and all, including any geogrid you put in it.

Determining if a steep slope such as you describe is close to global failure is unfortunately very difficult. Telltale evidence includes evidence of tree movement on the slope, scalloped areas, or areas where it appears that vegetation has slipped. Unfortunately unstable hillsides may appear to be stable when dry, but may become unstable after prolonged rain.

Excavation for a wall at the toe of a slope can destabilize the entire hillside if the hillside is close to failure. You may want to consult with an engineer for this project. Versalok does not, and will not, perform a global stability analysis for you.
Daniel Holzman is offline   Reply With Quote

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
Basement Concrete Wall Framing Against Stairs Epicsoccer Remodeling 7 01-13-2013 03:11 PM
Open Web Truss/ Load Bearing Wall Question rlc2052 Flooring 3 03-05-2010 09:37 AM
Retaining Wall and Muddy Yard rjschwar Landscaping & Lawn Care 10 02-24-2010 12:55 PM
Adding drainage to existing retaining wall? pcballgame Landscaping & Lawn Care 5 04-14-2009 03:29 PM
retaining wall luv2hunt Landscaping & Lawn Care 1 05-02-2008 07:45 PM

Top of Page | View New Posts


Search Engine Friendly URLs by vBSEO 3.6.1