cost of mse wall

[cvg]

we are looking at alternatives for a short (4 - 5 feet tall) retaining wall. MSE with concrete block facing is one concept we have thought of using. Backfill is level and good quality imported structural fill. Top of wall would have periodic surcharge from the occasional light vehicle or small construction equipment. (Maybe once or twice per year). Any idea what the approximate cost of the wall might be?

 

[fattdad]

This would likely depend on where you are located. I think I've heard $30.00/sf, based on the exposed face. Then again. . . . .

f-d

¡papá gordo ain’t no madre flaca!

 

[jdonville]

cvg,

It depends on the height and length of wall. Longer walls are more cost-effective. Higher walls get more expensive. Small wall area is generally more cost-ineffective compared to other wall systems that might be used (CIP cantilever, e.g.).

For your exposed wall height, a CIP wall could be a good option.

Jeff

 

[cvg]

CIP wall is one option among many that we are considering and I am just looking for a ballpark number. We are looking at a variety of options for raising this embankment and / or retaining it. The wall would be only 4 - 5 feet high and about 500 feet long. Embankment is high quality structural fill. $20 - $40 per square foot is the number we currently have and fattdad has confirmed my preliminary estimate of $30/sf. FD - does that include the geogrid and structural fill zone also? Or just the concrete facing?

 

[oldestguy]

While you are at it, hows about a 12 foot highwall with options for: gabions, modular blocks and cantilevered CIP concrete, as well as MSE, say 100 feet long?

I'm with the same question now. Thanks for bring it it up.

 

[msucog]

for very short walls, my statement may not be as big of a deal (some times i make a big deal since i see zero response from mse wall designers). where i'm at, the county requires certain letters to be provided by the wall designer and testing firm (testing firm required to send over all the test results and boring data-they are not required to confirm the wall construction was in accordance with the drawings). for a 12' high wall , there is very specific subsurface exploration, lab testing, and construction material testing that must be performed (the mse wall designer's report probably vaguely discusses some of this testing). the associated dollar figure is typically not included in the initial price provided to those comparing CIP vs MSE. also, some areas have soils that do not meet the mse wall specifications so graded aggregate may be required. the wall designers will sometimes change the specifications to accomadate site conditions. depending on which source you look at, the "industry standards" are widely varying. i happen to see NAVFAC as being a more reliable/independent reference (

http://www.wbdg.org/ccb/browse_cat.php?o=29&c=4).

i will issue a word of caution: the wall designer must provide a specific exploration and testing protocol that describes the required tests and frequency of testing. if they quote FHWA as their testing protocol or if they say the geotechnical engineer should provide the testing protocol, i suggest you move on to CIP walls. The wall designers are the ones that are responsible for the design as well as accepting/rejecting all materials used. also, much of the language i see on specs and drawings try to put 100% of the liability on the owner and geotechnical engineer/testing firm...this language should be rejected.

to resolve the issue, i suggest the mse wall designer direct all exploration and testing since the wall designs are proprietary and so that the price they give you will include all necessary testing. this will also remove some of the "scape goat" language. for owners, they should still strike any language that says the owner or their geotechnical engineer is responsible for all testing, design, etc.

 

[fattdad]

wall face, geogrid and placement of the reinforced zone.

f-d

¡papá gordo ain’t no madre flaca!

 

[civilperson]

Explore the benefits of a gravity concrete cast-in-place retaining wall. Perfectly suited to moderate and low heights. If 2500 psi concrete can be site delivered at 59/yard, probably 20-30% cheaper than cantilevered wall or MSE complete with backfill.

 

[cvg]

cost of reinforced concrete (Class A, 3,000 psi) is being estimated at closer to $400/yard, in place and it could be even higher. Although site is relatively close to town, access by transit mixers to the forms may not be possible, especially until after the wall is in place.

 

[concretemasonry]

It sounds like an ideal situation for a segmental retaining wall. For most systems, 3.5' to 5.0' are possible with a gravity wall if a very small set-back (1-3 degrees)is acceptable. The gravity walls in the published technical data are engineered, but they put the above limits of the wall to limit their liability.

With good soil very little geo-grid may be required if a thorough engineering analysis was made.

Our municipality even has standard plate designs for SRW walls for use when sidewalks and streets are realigned, but these are quite conservative "cookie cutter" designs to fit all.

 

[civilperson]

Complete in place cost usually include formwork, stripping, reinforcement, etc. Not "apples to apples" to compare to ready mix delivered price.

 

[JML4TCM]

Typical installed cost of a segmental retaining wall (SRW) (aka modular block wall) ranges from $18 to $30 per square foot of face. This includes block, fill and geogrid. The largest segment of the cost is usually the fill material if it needs to be imported to the site. If on-site soils are suitable, cost will be at lower end of scale. Geogrid embedment depths typically will range from 60% to 100% of the wall height depending on soil conditions and loads on wall. Also ground geometry infront and behind wall plays a big part of required embedment lengths.

 

[oldestguy]

Very good info guys:

I assume yours are ordinary sites. This site is in north-central US, with sandy soil throughout,including the imported fill, depressed area also. Original total job estimate was $80,000, but now added burocratic involvment requires new estimate.

However, site now is funded by a US Agency, with numerous hoops to jump thru. Davis-Bacon act now required.

I'll add about 20 to 40 percent to my estimates for that red tape, etc. Or should I go higher?

OK?

 

[MSEMan]

Here are some current numbers for you:

MSE materials $10-13 per s.f. including facing and reinforcements.
Construction $12-14 per s.f.
Backfill depending on where you are.
These are east coast current competitive costs. hard to estimate what you might pay with all the restrictios you face. Shouldn't matter to the materials costs but I'd add 40% to the construciton number.