Retaining wall Pile embedment in rock
Retaining wall Pile embedment in rock
(OP)
Hi,
We are about to try to design a retaining wall for a 15+m height of weathered volcanic ash above a 'soft' sandstone. Does anyone know of any simple way to calculate the embedment depth required to achive a cantilever action? All we have is a dynamic probe blow count on the sandstone at the site and general lab data for the sandstone from the local viciinty
We are about to try to design a retaining wall for a 15+m height of weathered volcanic ash above a 'soft' sandstone. Does anyone know of any simple way to calculate the embedment depth required to achive a cantilever action? All we have is a dynamic probe blow count on the sandstone at the site and general lab data for the sandstone from the local viciinty
Gareth Williams
Geotechnical Engineer,
Auckland New Zealand





RE: Retaining wall Pile embedment in rock
What type of structure are you envisioning to retain your weathered ash? It's not clear from your post.
I would imagine that analysis of a cantilevered wall (sheet, soldier, tangent, secant) would suffice for any of those types, although you will have to evaluate the lateral capacity of the pile-rock system using a p-y (LPILE, COM624P) or Brom's analysis.
See the COM624P User's Manual here (htt
For the retained height that you mention (15m), you may need to install tieback anchors or similar restraints to keep the embedment depth reasonable and reduce moments in the piles. Alternately, you might consider a MSE/RSS wall.
Jeff
RE: Retaining wall Pile embedment in rock
Since this would require 15+ meters of embedment for an entire steel sheet pile wall the modern techniques, suggested by jdonville are almost guaranteed to be cost effective.
www.SlideRuleEra.net![[idea] idea](https://www.tipmaster.com/images/idea.gif)
RE: Retaining wall Pile embedment in rock
We plan on using a barrier pile wall (soldier pile). MSE/SRW walls probably won't work due to limited extent available for geogrid length. Tie backs are under consideration, but again due to limited site width behind the wall, they may not be feasible.
Cheers
Gareth Williams
Geotechnical Engineer,
Auckland New Zealand