emporary shielding design
 

temporary shielding design
i am currnetly in the process of designing debri shielding for a bridge. the exterior parapets and some of the deck is being removed. the exterior portion will be supported by overhang brackets and the interior bay will have wooden 2" x 12" planks resting on the bottom flanges. my basic question is this: where can i find loading information for falling debri or any kind of demo work? i have looked in the aashto construction handbook and guide spec book for temporary work and i can't find anything. i have done overhang falsework design before but i have never done shielding design. it seems to me that falling debri will have more of a load impact than simple dead load but i am not sure how to calculate it. if anyone has any information for me i would appreciate it. thanks.
i would check with osha. they may have some useful information. good luck.
we specify 100 psf live load (impact included) for shielding design in our contract specifications; we also specify that any debris has to be removed within 24 hours.
f=ma
i've seen specs that require, in addition to 100 - 150 psf live load, that the design also be sufficient for a 1000# concentrated load falling 6'.
sheilding design requires a bit of educated guess work as to the loads.