基于刚架结构局部失稳原理的爆高计算

通过对拆除爆破中钢筋混凝土框架失稳过程的探讨,在分析立柱爆破后框架结构的内力特点后,提出了刚架局部失稳几个基本假定。采用极限载荷的分析方法,推导出结构适筋梁和少筋梁的极限弯矩计算公式。最后应用刚体系统虚位移原理推导出了刚架极限平衡状态下的临界压力,然后将该临界压力代入欧拉杆模型或阶梯压杆模型得到刚架局部失稳的最小爆高。该方法是基于几个基本假定和近似计算的一种工程实用方法,计算实例表明其具有较好的计算精度,可为工程爆破拆除设计和框架结构局部失稳现象的研究提供参考。

Calculation of Blasting Height based on Local Instability of Frame Structure

By discussing the process of RC frame instability in demolition and the internal forces characteristics of the demolished column of frame structure,some basic assumptions were taken on local buckling of frame. The a-dopted method of the limit load analysis was used to deduce the ultimate moment formulas of rare-reinforced beam and reinforced beam. Finally,the critical pressure of rigid frame limit equilibrium state was obtained by using the vir-tual displacement principle of rigid system,and the critical pressure can be used to acquire the minimum blasting high of local buckling model instead of Euler rod model or ladder bar model. The method is a practical engineering method based on a few basic assumptions and approximate calculation,which provided a reference for the blasting de-molishment design and the study of buckling phenomenon of RC frame structure.