Under the guidance of theoretical analysis of blasting recoil of frame structure and mechanics princi-ple,it is proposed that the height of the blasting cut is too high to building collapse,and the reasonable blasting height of blasting demolition of frame structure is also deduced.Combining with the project example and using AN-SYS/LS-DYNA,the numerical model of blasting collapse of frame structure is established,and the simulation results are in agreement with the actual situation,which proves that it is feasible to estimate the blasting recoil of building by numerical simulation method. Through the simulation and analysis of the directional blasting of a 12 story frame structure,it is proposed that the blasting of the frame structure building should have large overturning moment and small recoil,and the height of the blasting cut should be selected at half of the gravity center of the frame structure. In order to make the building blasting in a small way,the rear column should be also blasted,and the blasting height is only required to form a rotating hinge at the root of the rear column.Otherwise,the strength of the column root should be weakened to ensure that the building body forms a rotating hinge at the root of the column.In order to pre-vent recoil,a certain height and strength of soil slag can be heaped.%以框架结构爆破后坐理论分析为指导,根据力学原理,提出爆破切口高度太大不利于楼房倒塌,并导出了框架结构爆破拆除的合理爆高.结合工程实例,利用ANSYS/LS-DYNA建立框架结构爆破倒塌的数值模型,其模拟结果与实际情况基本吻合,表明采用数值模拟方法预估楼房爆破后坐是可行的;通过对12层框架结构定向爆破的模拟分析,提出框架结构楼房爆破,要倾覆力矩大,产生后坐小,爆破切口高度应选择在框架结构重心H0的1/2处;要使楼房爆破后坐小,后排立柱也要炸,爆高只需在后排立柱根部形成转动铰支即可;若后排立柱不炸,应削弱柱根强度,以确保楼体在柱根处形成转动铰支;为阻止楼房爆破时后坐,可在楼房后排立柱根部堆一定高度和强度土渣.
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