爆后钢筋骨架零长度塑性铰失稳判别模型与试验验证

Discriminative model and experimental validation of zero-length plastic hinge instability of post-burst reinforcement skeleton

为了进一步研究骨架的残余承载能力对建(构)筑物失稳倒塌的影响,基于爆破后立柱钢筋骨架形态及其受力情况,建立了零长度塑性铰计算模型,并开展了不同爆破破坏程度下残余钢筋骨架的承载能力测试试验。结果表明:高度和弯曲程度对承重立柱爆后钢筋骨架承载能力有显著影响,当初始挠度接近时,试件峰值承载力随骨架高度增加呈线性降低关系;当骨架高度相同时,试件峰值承载力随弯曲程度增加呈非线性降低关系;与传统欧拉等直压杆模型和初弯曲压杆模型相比,零长度塑性铰失稳判别模型的计算结果更接近模型试验值。论文研究成果对高大建(构)筑物拆除爆破设计和抗连续倒塌分析具有一定参考意义。

In order to study the impact of the residual load-bearing capacity of the skeleton on the instability and collapse of buildings(structures),a zero-length plastic hinge calculation model was established based on the shape of the column reinforcing skeleton and its stress after blasting,and the load-bearing capacity tests of the residual reinforcing skeleton were conducted under different degrees of blast damage.The results show that the height and degree of bending have a significant effect on the load-bearing capacity of the column reinforcement skeleton after blasting,when the initial deflections are close,the peak load capacity of the specimens decrease linearly with increasing height of the skeleton.When the heights of the skeleton are the same,the peak load bearing capacity of the specimens decrease non-linearly with the increase of bending degree;Compared with the traditional Eulerian isotropic compression rod model and the initial bending compression rod model,calculation results of the zero-length plastic hinge instability model are closer to the test values.The research results have certain reference significance for designing the demolition of tall buildings(structures)by blasting and analysing anti-continuous collapse.