I-Beam Conection to Stump and Joists

Unfortunately I need to span over a disused septic tank and my engineer has specified a 100UC15 I-Beam bearers for the extension I am building.

2 questions

1) How the hell do I attach the I-Beam to a 100x100 concrete stump with a threaded rod in the middle when the web section (ie the verticle part) would sit directly above the threaded rod. Thought about off centering 15mm but not too sure if this is ok since the flange would not rest directly on the stump ?

2) How do I attach 100x45 joists to the I-beam. Onesteels guide suggests a steel strap but i'm not sure that method is secure enough.

Many Thanks in advance

Chris

Ditch the concrete stump and put in a 90x90 steel post with a plate on top. Drill the plate and the flange of the beam to take four M12 bolts, one in each corner.

You can bolt a timber plate to the top of the beam and then fix your joists to that, or you can weld lugs to the beam and screw or bolt your joists sideways.