A Necessary Way to Build Road Embankment?

[BigH]

Me again – want to get my colleagues take on the following. The other day, our safety officer indicated in a meeting with our roads contractor who is building a large rockfill embankment that he “needs” to build the embankment by building an edge berm first, then infilling inside the berm with the layer. The berm is supposed to be for “safety” so that equipment doesn’t fall over the edge (1.75H:1V slope). Has anyone in our group ever built an embankment this way? Has anyone ever seen an embankment built this way? Sometimes I shudder and it isn’t that Indonesia is too cold . . . .

 

[jheidt2543]

I guess the question I would ask the Safety Officer is "Why is it any safer building the two outside berms first, rather than just building the whole berm?" In my estimation, the chances of a roll-over accident are at least equal and maybe higher. You sitll have the outside edges at 1.75:1 to roll down.

In addition, is the Safety Officer prepared to write a change order to pay for the added expense of this change in operations he is asking for?

And lastly, I would think compaction would suffer along the "inside" edges of the safety berms. It just seems to me that compaction would be easier and more consistant if it were all done in lifts across the entire top.

Just my two cents!

 

[Ron]

BigH...never seen it done that way. I suppose there's some safety logic to it, but most earthwork contractors wouldn't get excited at all with that slope.

There's always an opportunity for rollover...whether the berm is there or not. Building the berm would require more movements perpendicular to the slope (unsafe) as compared to the typical movements of up and down the slope.

 

[emmgjld]

I have been on similar constructions where the goal was to minimize rocks rolling down the embankment and
when constructing a mechanically stabilized fill, with either geogrid or fabric.

 

[GeoPaveTraffic]

Never seen it done that way.

Usually it is just the opposite. You keep the ceneter of the embankment higher than the oustsides so that rainwater can drain off the embankment. As a matter of fact when specifiying dam construction, we require that the ceneter be kept higher than the outside edges.