A.按x=ξbh0計(jì)算 B.對(duì)受壓鋼筋合力點(diǎn)取矩求得,即按x=2a′s計(jì)算,再按A′s=0計(jì)算,兩者取大值 C.對(duì)受壓鋼筋合力點(diǎn)取矩求得,即按x=2a′s計(jì)算,再按A′s=0計(jì)算,兩者取小值 D.按最小配筋率及構(gòu)造要求確定