I am looking a replacement for these and don't know what they are called or where to find them. These are on a wire shelving stand and holding two shelves together. Any help is appreciated. Thanks!

I work on a marina and some of the Walers that are split. Unfortunately, do to the length of the boards - 24' - and how the dock is constructed, we can't easily remove the piece and replace it like we can on the other parts of the dock as this particular board is on a main walkway and would require a lot of structural components to be removed. I'm wondering if someone makes a larger version of a toggle bolt - like what is used for dry wall anchoring - but what would work in this application. My idea is that I'd drill a vertical hole through the board - passing through the two split pieces - and then inserting this bolt. Tightening it would join the split pieces. Alternatively I thought of just using bolts with large flat washers but there are locations where I wouldn't be able to reach to the underside of the board to thread on a nut. Attached is a picture from the internet with a quick ink illustration of what I'm talking about. The diagram is on the outer edge of the dock but would actually be going through the board closest to the concrete - I made a little red circle indicating the location.