Retaining Wall Failure Caused by Water

[fuatilhan]

i hate when top rated comments are too long to read...

[beranbr]

To me this shows a lack of inspections and a lack of communication. Walls of this size needs to be inspected during the entire building process to ensure proper wall construction. Also, there needs to be some sort of communication between the engineer and the developer and the builders. Simple solution is to make it very clear that no building is to collect and empty storm water directly behind the wall.

[jhantonio]

So basically people shouldn't buy houses near a retaining wall, right? I mean why take the risk?

[LaszloBencze]

Moving the drainage to the opposite side of the wall is an invitation to an even worse disaster. The most basic principle of soil is that it’s structure disappears upon saturation. A properly designed wall has a gravel curtain many times the thickness of the wall extending from footing to grade, and a properly designed footing drain field to capture the water and carry it away in a water tight line to a community drain or swale that is well outside the load plane of the wall and slope.

[RetainingWallExpert]

@LaszloBencze You are right on the money. If the water is discharged just onto the slope in front of the wall then there will likely be erosion and problems caused by that water. The water needs to be collected and discharged downslope sufficiently in front of the wall to prevent: (i) saturation of that hillside; and (ii) erosion of any of that soil. Good comment! Thanks!

[ehunter2]

I built a 3" pvc pipe system around the perimeter of the house that runs out to the street and empties into the storm sewer. The downspouts

tie into it. No more water collection around the house, the crawl space is dry and the yard

never floods. Cheap, fast, effective.

[RetainingWallExpert]

Geogrid is holding up buildings and structures all over the world - reinforced walls and soil structures have been built nearly 300 feet high that are safe and permanent. I'm a registered Professional Engineer in more than 15 states and have been involved in several block walls nearly 50 feet high that are performing very, very well. You should learn more about these walls, and try not to form an opinion based on your limited experience with these walls.

[pgiske]

It appears no drainage system was provided to direct water away from the wall. 5yrs ago, I built a 100'+ retaining wall using 12" wall block with sections of the wall as high as 6.5' tall. This wall was built below the shoulder of a residential side street. I placed a 4" corrogated, perf-drain pipe at the base behind the first course of blocks w/ outfall at each end. Next, I placed weep holes along the base course at 3' intervals. Lastly, I backfilled with 5/8" drain rock. It still stands today.

[okbye1]

sounds good pgiske. In the video I cant even see any mortar on the blocks.

and even without the house drain I dont think it takes a rocket scientist to figure out you cant build a mud swimming pool and not have it affect a porous block wall eventually. It seems some kind of weep holes should help the integrity of the wall.

[RetainingWallExpert]

Guys, the wall did have drainage incorporated. First, there was a 1-foot thick column of stone behind the walls. Second, the entire geogrid-reinforced zone was made of free-draining stone. Mortar is never used in these kinds of walls, it is not needed. The drainage pipe discharges lower on the hillside - you just can't see it. However, the downspouts are just TOO much water, and caused this failure.

[kelpheadtwo]

tell me.

a block wall with threect stucco and the wall is saturated with moisture, you can see the block and salts are formed on the wall. we put some weep holes in, 7 ft wall, and found there was rocks behind the wall, but the new weep holes remainded dry, still outside of the wall is wet. ??

[ButterflyDragon9]

@RetainingWallExpert

Having done commercial roofing work for quite a few years, I can attest to the fact few people realize just how much water is delivered to an area via a spout.

[nazmikarakoc]

Why not use geogrid to reinforce that wall?

[kowalski751]

The wall was reinforced with geogrids, spaced every 2 to 3 blocks vertically, and used an angular granular fill. So, even with geogrids installed, the water from the downspouts was able to do a lot of damage.

[davetileguy]

I dissagree with your assesment,you say there is gravel behind the wall,I see NONE! the water is being deposited against the back of that wall while not technechly correct it should quite easy for it to weep out the face of the wall,also as extra insurance all walls should lean a few extra degrees into the load.

[RetainingWallExpert]

Dave,

You are right there was no gravel behind the wall blocks, but only in the upper 1-2 feet of the wall. Also, the contractor did not put gravel in the cores of the block, which reduced their weight. Below that, there WAS gravel in the cores and to 1 foot behind the blocks. This wall does batter back a few degrees. I like the way you approached this problem! Stop back soon! Best regards, Joe K.

[jpl0072006]

Great video! Keep up the great work. YouTube needs more videos like this.

[NicoKersting]

Excellent. Show more of these videos!