A municipality has recently reached out with an emergency project. A slope directly adjacent to an existing road is showing serious signs of instability. The problem area is approximately 40 feet in length (along face of wall) and a maximum height of 20 feet. I mainly design temporary and permanent anchor earth retention systems (i.e. tiebacks, soil nails, helicals, etc.) however the wrinkle in this project is the road is directly tangent to a curve in a stream at this location.
I'm still in the fact gathering stage of this project, but from what I've seen the existing soil slope appears to be at a 2V:1H slope. We're collecting survey data and geotechnical borings now, but the municipality would like the road geometry and stream geometry to remain unchanged. So my first thought was sheet piles, however in the pictures I've been sent the stream bed appears to be rock and/or boulders.
So my question is if a sheet pile wall won't work due to constructability, and an MSE system won't work due to existing geometries is there a way to mitigate scour concerns using either a soil nail wall or soldier pile will? I know GEC 7 essentially says alternate systems should be considered if scour is a factor for traditional soil nail walls, and I haven't found anything in GEC 4 addressing scour. I myself am still researching any publications which would address this issue, but figured I would ask here concurrently.
As always, any help is appreciated.
Thanks.
I'm still in the fact gathering stage of this project, but from what I've seen the existing soil slope appears to be at a 2V:1H slope. We're collecting survey data and geotechnical borings now, but the municipality would like the road geometry and stream geometry to remain unchanged. So my first thought was sheet piles, however in the pictures I've been sent the stream bed appears to be rock and/or boulders.
So my question is if a sheet pile wall won't work due to constructability, and an MSE system won't work due to existing geometries is there a way to mitigate scour concerns using either a soil nail wall or soldier pile will? I know GEC 7 essentially says alternate systems should be considered if scour is a factor for traditional soil nail walls, and I haven't found anything in GEC 4 addressing scour. I myself am still researching any publications which would address this issue, but figured I would ask here concurrently.
As always, any help is appreciated.
Thanks.
