Holes in Concrete Walls or Tanks
Holes in Concrete Walls or Tanks
(OP)
I am designing several concrete tanks and there will be penetrations through the tanks to accomodate large pipes (say 36" in diameter). Does anyone have any design examples or design methods for determining reinforcing around penetrations through concrete tanks or concrete walls?






RE: Holes in Concrete Walls or Tanks
RE: Holes in Concrete Walls or Tanks
RE: Holes in Concrete Walls or Tanks
One of the posts in that thread states to do an analysis based on a reduced section. There is no section at a penetration. What would be a rational way to determine the moment and shear that needs to be transfered at the edges of and opening (left and right sides, top and bottom of opening) in addition to the moment and shear that is present in the wall if no penetration exists?
RE: Holes in Concrete Walls or Tanks
RE: Holes in Concrete Walls or Tanks
Also, depending on how you are placing your inserts, box outs as opposed to cast in, I have often seen an internal rebate within the box out which serves to act as a waterstop and a mechanical key for groutings afterwards. A hydro expansive waterstop is also a good idea around the cast in item.
I think the method of design for the wall depends on the size of the opening with respect to the wall. If it is large you would need to consider the wall in terms of strips and panels supported on two sides. If small you can consider the wall, as a wall and just make local modifications to suit the opening. It all comes down to a judgement call from the Engineer as to whether the wall acts like a wall or not.
RE: Holes in Concrete Walls or Tanks
RE: Holes in Concrete Walls or Tanks
The Commentary to 13.1 reads: "The fundamental design pronciples contained in Chapter 13 are applicable to all planar structural systems subjected to transverse loads." Excluded are one-way slabs and slabs-on-grade.
Moving the reinforcing to the sides and top and bottom of an opening (together with diagonals) essentially creates a set of beams within the slab to carry the forces around the opening.