烟囱爆破拆除中动荷效应的影响分析

Analysis for Dynamic Load Effect of Chimney Blasting Demolition

在烟囱爆破拆除中,现场实测数据表明爆破瞬时烟囱受到动荷效应的影响,若爆破切口角设计不当,会影响烟囱倾倒方向的准确性。根据能量守恒定律,推导出烟囱爆破冲击动荷因数的计算公式,研究了烟囱爆破切口余留薄弱截面上的动应力。通过对爆破冲击载荷作用下切口余留部分应力的理论计算,得出保证烟囱不发生下坐切口角的上限值。结合工程实例和现场实测数据验证了理论的正确性。

In the Chimney blasting demolition, field data shows that chimney is affected by the dynamic load effect in blasting instant. If the blasting cut angle is designed improper, it will affect the accuracy of the chimney dumping direction. Relies on the law of conservation of energy, the computational formula of the impact dynamic factor of chimney blasting is deduced, the dy- namic stress of the remaining weak cross-section of the chimney blasting cut is studied .By theory calculating the value of the stress of the remaining part under the action of blasting impact load, comes to the higher limit of the cut angle which ensuring that the chimney would not sitting down. Engineering examples and field data are given to verify the correctness of the theory.