Boulder Retaining Wall
Boulder Retaining Wall
(OP)
I have a client who has an already installed retaining wall which is built in steps. It varies from 2'-10' in height. I have not seen it yet but he said the boulders are the size of cars. The town engineer wants calculations submitted. To me, this is just a pile of rocks and it would be tough to calculate anything. Are there any referneces or guidelines for this type of wall. My initial guess would be to take the weight of the boulders and see if the friction at their bottom is more than the soil lateral loads. There is no footing and no typical "retaining wall action" so overturning and bearing at the toe dont seem to come into play. Any advice or guidance would be appreciated.





RE: Boulder Retaining Wall
RE: Boulder Retaining Wall
RE: Boulder Retaining Wall
The concern that we have with analyzing boulder walls as a gravity wall is that you when you analyze overturning you cannot sum moments at the base of the wall. There is no rigid connection that will transfer forces from the top to the bottom of the wall. There is frictional resistance between the rocks so I guess there could be some transfer but how much depends on several variables (rocks, quality of construction, etc.)
I would be interested in your thoughts on this.
Thanks.
RE: Boulder Retaining Wall
RE: Boulder Retaining Wall
RE: Boulder Retaining Wall
You are partly right. The overturning moment at every depth of the wall must meet the requirements of the design. Now, at the top of the wall, for overturning and sliding you may require a width of say 1 meter. As you progress down the wall the requirement increases so that at the base of the wall you need a width of 3 metres to maintain the stability against overturning and sliding. So, ok, now you need a wall that is 1 metres wide at the top and 3 metres wide at the base.
The point is that you must maintain stability at all levels of the wall. This is true for your case but also for Allen block or Keystone walls as well.
jim
RE: Boulder Retaining Wall
RE: Boulder Retaining Wall
you are quick! good luck!
jim