I'm working on a flood defence scheme in which a section of RC flood wall becomes sheet piles. The reasons for this aren't important, but the solution isn't to simply make all walls one or the other.
My issue is how to connect these two very different types of wall in a way that provides an expansion joint for the concrete but is also water-tight. This isn't an issue for connecting individual concrete panels as a waterstop is simply cast into the expansion joint, providing a seal. However, sheet piles don't have anything to 'cast' onto.
My idea so far is to design a sort of concrete (possibly mass, probably RC) 'pilaster' at the end of a section of sheet pile that will allow a water stop to be cast into. However, sheet piles deflect a fair amount which is making me wary of casting a rigid concrete section at the end of the sheet pile.
I'm at a bit of a loss here and struggling to find a precedent of a connection like this. SURELY it's been done before?
I've attached a quick hand sketch. I'm not too bothered about detailed calculations for this; I'm more interested in solving the buildability issues at the moment.
Dimensions are subject to minor alterations but roughly:
- The RC wall penetrates 1.5 m below ground level
- Sheet pile penetrates 6 m below ground level
- RC wall stem is ~350 mm thick
- Sheet pile section is 450 mm thick (AU25 section)