concrete basement wall cast around steel columns

huangyhg

concrete basement wall cast around steel columns
i am working on a two story building that has a basement wall on one side of the first floor.  after discussion with the contractor/client we have decided to build the steel frame as a normal two story building and cast the basement wall around the hss columns along this one wall.  this is necessary to simplify the concrete formwork and to provide for a brick ledge.  the steel frame outside edge of steel is flush with the outside edge of the infill steel studs on the floor above (ie, the hss columns are not inset from the exterior wall).  with that, i have designed the frame to not rely on the basement wall, but i am looking for advice on whether to 'connect' the basement wall to the column compositely or to separate them with a filler.  the wall will be poured such that the inside edge of steel will be flush with the inside face of the basement wall (the columns will be encased on three sides). my original instinct was to leave the wall independent from the columns with felt expansion material, but i thought i would seek the advice and experience of others.  
i agree with your proposal, since the steel structure is designed to act independently of the wall.  however, you should check that if the basement wall deflects due to the lateral earth pressure, that it will not apply a lateral load on the columns, or if it does, then the structure should be designed for the lateral load.
if you live in a cold climate, you should check that there is sufficient insulation so that the steel columns don't get condensation on them, which would lead to rust.
yes the wall is designed for at rest pressure.  larger wall but very little deflection.  thus my question as to separate or tie together.  thanks for your input.