Respected sir,
My name is Nihar Shah. I recently start using staad pro. But some how i face some difficulties in giving earthquake in staad pro. Bcs it is apply by two method one method is joint method and 2nd method is lump mass or member weight or floor weight
but i want to know the reason when we apply earthquake by lump mass we have to remove all global directions and also negative sign.
i just cant understand logic behind this can u pls explain.
Thank u