progressive collapse, masonry panel restrain

huangyhg

progressive collapse, masonry panel restraint
i'm working on an grade ii listed warehouse. we've argued the 34kn/m2 explosive force down to 17 and are now contemplating how to tie the wall to the floors. cast iron beams carry timber joists which can not offer the tie restraint needed @ half a floors height the reaction is 25kn/m.
on the upper floors there is insufficient axial dead load as suggested in bs5628 cl 37.1.1. so i'm considering tie bars with patress plates. my problem is how to tackle the design of a masonry panel that is effectively acting like a flat slab.
the existing wall is solid @ 600mm thick with dressed stone outer skin.
i'm not sure if i can approach it with moment coefficients and punching shear checks in similar fashion to bs8110??
obviously being grade ii we need to keep the visible impact to a minimum.
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the critcal zone for shear is around the patress plate as the distribution of load through the brickwork will be based on the shear planes through the bed joints. this makes the perimenter around the patress plate the critical zone. the design of the brick panels could be based on bs8110 principles taking due account of the poorer bending properties of the wall across the bed joints as opposed to along them.
i designed solid brick walls, supported on three sides and subject to triangular loading distribution, many years ago to cp111 based on bares - design of plates and shells. the walls were still standing the last time i looked.