Retaining wall footing attaching to bedrock
Retaining wall footing attaching to bedrock
(OP)
I have a 20' concrete retaining wall I've designed and is being constructed. The contractor is hitting what he thinks is bedrock (most likely it is) near the obviously large footings for the wall. He wants to tie in to the bedrock in lieu of getting all the rock (most likely granite and basalt) out of keyway and heel of the footing.
I know to look for cracking in the rock to be greater than 3' apart and to verify competent rock. I'm planning on coming up with a drilled epoxy dowel schedule to incorporate the footing to the rock, beyond that I'm not sure, has anyone had experience with this situation?
I know to look for cracking in the rock to be greater than 3' apart and to verify competent rock. I'm planning on coming up with a drilled epoxy dowel schedule to incorporate the footing to the rock, beyond that I'm not sure, has anyone had experience with this situation?





RE: Retaining wall footing attaching to bedrock
if it's competant, mass rock, i've seen some folks spec drilling and epoxying rebar in to the rock. for relatively small walls, i've seen it spec'd drilled 6-8" in the rock and spaced 6"-12" along wall. it depends on the design and reinforcement.
20' tall wall is pretty large so i'd suggest putting your head together with the geotech to come up with a solution.
RE: Retaining wall footing attaching to bedrock
RE: Retaining wall footing attaching to bedrock
f-d
¡papá gordo ain't no madre flaca!
RE: Retaining wall footing attaching to bedrock
1. Make sure he has reached "Bed Rock", not a huge boulder, which may complicate your solution.
2. What is the water table? Any consideration on potential corrosion on the epoxy dowels? Will the wall still stable if dowels are gone?
RE: Retaining wall footing attaching to bedrock
Again - ask the geotech...
Mike McCann
MMC Engineering
RE: Retaining wall footing attaching to bedrock
Analyse like a concrete beam or steel base plate design with the bearing pressure as limited by the geotech.
RE: Retaining wall footing attaching to bedrock
So, like a beam on elastic foundation analysis, with really high soil modulus values in lieu of the rock pressures? Thanks