Steel vs Vinyl sheet pile wall 9

[pelelo]

Engineers,

I am involved in a project that will consist on the installation of either a steel or vinyl sheet pile wall. The purpose of this is for flood control. According to the geotechnical report, the depth of the wall is approximately 25 feet. Nearby the area there are trees, that eventually will need to be removed to allow access to equipment.

I have worked in the past with steel sheet pile installation and i am sure during the driving, the steel sheet piles will be able to break through any big roots that are on the way. I am not sure if with vinyl sheets it will be able to do this and i am not even sure if with vinyl we can go 25 deep.

It is my understanding that vinyl is cheaper than steel.

I just wanted to know what would be advantages of using vinyl for this type of project compared to steel, if it is even an option.

Please let me know.

 

[DaveAtkins]

My experience with vinyl sheet piles is for short walls, with a vertical cut of less than 10' as I recall.

If your vertical cut is 25', I am fairly certain you will need steel sheet piles.

DaveAtkins

 

[CivilKeith]

You can evaluate the structural capacities of the vinyl sheet pile wall and maybe make a case, but my gut feeling is telling me that 25' is going to be too deep for vinyl to be economical or structurally sufficient.

 

[pelelo]

Thanks,

Please keep in mind that this wall is for flood control purposes, there is no earth retention on either side (~ 5 ft of cantilever, then the remaining 20 ft, is embedded).

 

[PEinc]

Plastic sheet piling has a fraction of the strength of steel. Therefore, 5' to maybe 7' may be about the maximum retained soil height that plastic sheet piling can cantilever. If higher, you will need tieback anchors or tie rods with deadmen. I would also expect plastic sheet piling to be damaged when hitting tree roots or other obstructions.

http://www.PeirceEngineering.com

 

[GeoEnvGuy]

I have records of a vinyl sheet pile wall constructed for a flood containment reservoir with 20 foot panels and having no issues. The panels were pushed through a swamp and refused on dense till or bedrock.

We also recently pushed steel panels in a nearby location with similar geology and the steel panels refused on dense till and bedrock. Problem for us is the steel wall is supposed to be used as a retaining wall and the embedment is not sufficient in all locations.

 

[ATSE]

GeoEnvGuy: please take no offense, but the 20 foot number just doesn't sound right at all. My experience with FRP sheet piling (stronger and stiffer than vinyl) is about 10 ft max of unbalanced hydrostatic load. Would you mind showing details or simple calcs or pictures of what you're talking about? Did this installation you are referring to actually "see" the design loading? Vinyl certainly has its place in the market - mostly for 4ft to 8ft stub seawalls in the bay, but my experience is that it is oversold for taller walls and higher-load applications. But I'm listening...

 

[cvg]

https://www.compositesworld.com/articles/on-the-waterfront-composite-marine-piles-build-on-success

 

[GeoEnvGuy]

Hi ATSE to provide more context thon the 20 ft section I have include pictures below. The vinyl sheet pile wall was constructed to maintain the pore pressures outside of the reservoir (right side of photo 3) so that the inside (left side of photo 3) could be excavated to form the reservoir. The vinyl sheet pile wall is not used in a retaining wall application without the support of rockfill. In the design flood conditions the inside which is typically a lot lower could overtop to the vinyl sheet pile wall in a rockfill channel section.

 

[cvg]

how did you place the rock without damaging the piles?