切口方式与延期时差对框架结构爆破拆除效果的影响

切口方式与延期时差对拆除爆破倒塌效果有重要影响,尤其是对小高宽比的框架结构。因此,通过数值模拟对结构倒塌效果进行分析,对于爆破方案的选取具有一定的指导意义。针对某9层框架结构拆除爆破实例,利用ANSYS/LS-DYNA有限元分析软件,采用整体式模型,对不同切口形式和延期时差的框架结构倒塌过程进行数值模拟。对框架结构底层最后一排立柱拆除与否,以及最后两个爆破区段延期时差分别为0.3 s或0.5 s,这4种情况下的结构倒塌进行对比分析。结果表明:在爆破切口延期时差相同时,底层最后一排立柱拆除,框架结构的塑性铰形成位置较不拆除时下降,结构解体完全,爆堆高度也降低,倒塌效果较好;在相同切口形式时,爆破区段延期时间不同,框架结构塑性铰形成位置和倒塌效果也有所不同。

Influence of Cut Pattern and Delay Time Difference on Effect of Frame Structure Explosive Demolition

Notch pattern and delay time influence the collapse effect of explosive demolition greatly,especially for small height-width ratio frame structure.So,it is of certain significance for the selection of the blasting scheme through the numerical simulation.A blasting demolition case involving a 9-layer frame structure,the ANSYS/LS-DYNA finite element analysis software and the integrated model were used to simulate the collapse process of the building.Different notch forms and delay time were set in the process during numerical simulation.A comparative analysis was used in the process of four cases,such as the bottom column in the final row was demolished or not,and the delay time was set as 0.3 s or 0.5 s.The results showed that,in the bottom column demolition in the final row,the position of the frame structure plastic hinge was lower than that with no demolition.The structure disintegrated completely and muck pile′s height was reduced,showing good collapse effect.By keeping the notch form constant and delay time different,the plastic hinge position and the collapse effectiv are also different.