Search results for query: *

There are many MSE walls in service that have negative batter. The situation probably arose due to the difficulty of working in the confined spaces between the piles and the wall face. Depending on the fill used, the contractor may have found it difficult to get adequate compaction in these...

Problem with the soil nail launcher will be the depth of nail. For a 20m wall you'd need at least a 12m nail and the launcher only really goes to about 6m. So your looking at drilled nails or tie backs. There is no reason to shotcrete the facing unless you have corrosion issues on the facing...

Augustus - I can provide you with a detail for attaching soil nails to precast facing if you want to look at that.

You can infer one from the AASHTO MSE wall sections on traffic barriers and FHWA-00-044 publishes a detail.

For many typical retaining walls, you'd ignore passive (unless its on the shear key) and even then you need to be careful because the retaining wall may not be able to tolerate the movement necessary to generate full passive resistance.

KaBone, This shouldn't be a big deal unless you are dealing with very poor native soils. Put it out to bid on a design/build basis and save your fees to develop a performance spec and evaluate the alternates that come in. Make sure the contractors have the appropriate levels of E&O, and...

Actually the barrier isn't such a big deal if it's designed correctly. There are a few things that matter a lot. If the barrier is placed on top of the wall facing before the anchor slab is cast then it will rotate about the support point at the top of the facing. On the other hand if the...

C'mon guys - back to basics: It doesn't matter in which face the wall is reinforced, that could not explain a lean in the wall, maybe cracking, but not a lean. The wall is rotating, apparently about the toe, so it is a global failure rather than (or additionally to)a structural one. My first...

MSE walls are often used in river wall applications - BUT: You need to carefully evaluate the potential for scour and provide appropriate scour protection if this is appropriate. In addition you need to assess how the qualities of the in-situ soils will change when wet. Im hoping that the...

We've done a few of them using MSE walls with precast concrete panel facings. These systems are usually built with vertical facings (highway retaining walls and bridge abutments). See: www.earthteccorp.com www.recousa.com www.tricon.com You will want to use high quality (i.e. frictional...

I agree with miecz, when your talking roads your into AASHTO design. AASHTO specifies 250 psf. To think that the only vehicle to ever traffic over the wall would be an empty logging truck is a bit aggressive - what about when the fire truck arrives?

Woven geotextiles usually have an order of magnitude or so less strength than geogrids (per unit width) but have small aperatures, and are thereofre more suitable for separation applications. If you are going over peat, you may need to use both, a geotextile to separate the road base from the...

snsl23, Glad to hear its worked out, more or less okay. But the point is that you still have, in effect, granted a permanent easement onto your property without getting compensated for it. And you have no idea what the extent of the encroachment onto your property actually is. You need to...

It would be almost criminal to ignore the load for overall stability considerations. Your wall is a very small part of an overall embankment condition and the Cooper E80 loading needs to be part of the analysis of that overall condition. I agree with others that for internal stress (sigma v)...

Why don't you excavate out the existing fill and build a MSE wall 12" behind the existing wall? Use wire mesh facings and wrapped geogrids or geoynthetic sheets. While some codes require 8' minimum geogrid lengths, you can get it to work with 6' lengths. It's pretty easy to design and will...

Generally speaking you design the resistance of the shear key as if it were retaining the loads and soil above it with stiffness of the soil = Kp. So use a pressure that corresponds to your geometry. However, it takes a fair movement in a soil to develop Kp so make sure that you are prepared...

Well it's very difficult to ignore the force effects, becasue they are very real. However, if structures are allowed to undergo some "permanent deflection" a portion of those force effects are accomodated by a non-destructive change in position of the structure. One formula often used is: Kh...

The engineering issue with compaction was developed in a paper by Ingold, very often referenced. When you run compaction plant against a wall, you lock in a portion of the compaction stress since the wall is stiffer in the partially backfilled state then it is in the theoretical completed...

So you want to do MSE wall design? Just as a matter of principle - do you understand the strenghts and weaknesses of the design concepts? How are modular block wall different from traditional MSE panel walls, and wire faced walls? Why is frictional fill important? Why do so many modular block...

Use the FHWA Manual NHI-00-043 which deals directly with internal stress analysis and superimposition of loads. You will need to use a decent slope stability program to model the global stability.