self climbing placing booms can be fixed by steel frame instead of making a square-cut in the  concrete slab?

we have  now one site has only one space in service core .the dimension of the core hole  is 1m *3m so we have to add a steal beam to make this hole 1mX1m?any one has any suggestions? 

Putzmeister published a project profile of something like what you're looking for some time ago - they used a steel weldment to turn an elevator shaft into a steel placing Boom hole.   Go to page 28 of the following .pdf - http://www.premierpumping.ca/img/PDF-%20Putzmeister-PlacingBoom.pdf     

i'm sure you know, but you'll have to get the configuration and force/moment diagram for the manufacturer of your placing boom and system you're using, and have the engineer of record on your building do the steel frame design or have him work with the manufacturer, or a third party engineer to design the steel opening.    It's actually pretty straight forward, and when you run the numbers the steel beams come in smaller than you'd think given the task it's performing.     message me if you need some guidance.