La chn v tớnh toỏn cỏc thit b treo buc dn nh: dõy cu, khúa bỏn t ng, m chng góy, ũn cu, khung cu, dn cu Khi dn loi nh cú th ch s dng dõy cu. Khi dn loi ln phi s dng ũn cu, khung cu, dn cu
2. B trớ dn thộp trờn mt bng Dn c b trớ trờn mt bng cu lp dc theo tuyn di chuyn ca cn trc, cn b trớ dn[r]