介绍了处于繁华市区的两栋框架大楼定向爆破拆除的施工方案、爆破参数和起爆顺序。虽然楼房按预期的方向倾倒 ,但有一部分后承重柱被高位拉断。文中简要阐述了后承重柱高位拉断的机理 ,指出了在上部载荷足够大和已具备足够的倾覆力矩的条件下 ,追求过大的炸高 ,是后承重柱高位拉断的根本原因 The construction scheme, blasting parameters and initiation sequence of directional blasting demolition of two frame buildings in downtown are introduced. Although the building was dumped in the expected direction, some of the load-bearing columns were pulled high afterwards. In this paper, the mechanism of post-load-bearing column pull-off at high level is briefly described. It is pointed out that the pursuit of excessive blast height under the condition of sufficient upper load and sufficient overturning moment is the root cause of high post-load column pull-off