为综合评估战后建筑结构的毁伤等级,针对爆炸作用下典型地面建筑,即含填充墙钢筋混凝土(reinforced concrete,RC)框架结构,提出了损伤破坏和倒塌的高精度数值仿真分析方法,并通过RC结构爆炸试验、倒塌事故和砌体墙爆炸试验进行了充分验证;开展了典型 3 层原型RC框架结构在不同爆炸当量(25～200 kg TNT)下的内爆炸数值仿真,定量分析了爆炸冲击波在建筑结构内部的传播、结构损伤破坏和墙体飞散等.爆炸作用下建筑结构的高效毁伤评估流程为:结合镜像爆源和非线性叠加原理确定内爆炸荷载,基于等效单自由度方法评估梁、板、柱及墙体构件的毁伤等级,引入构件重要性系数加权确定房间毁伤等级,考虑房间功能及位置重要性评估整体结构的毁伤等级.高精度数值仿真分析与毁伤评估方法计算的典型RC框架结构的整体毁伤等级一致,即在 25、100 和 200 kg TNT爆炸下RC结构分别呈现轻度、中度和重度毁伤,毁伤评估方法可缩短 99％以上的计算耗时,兼具可靠性与时效性.
High-efficiency assessment method of damage for building structures under explosions
Damage assessment of building structures plays an important role in military operations and engineering protection design.However,there is a lack of high-efficiency and validated damage assessment methods due to the complexity,variety,and large size of building structures.Therefore,a structural damage assessment method was proposed based on the high-precision numerical simulation analysis,in which the blast loadings,as well as the damage degrees of members,rooms,and building structures,were comprehensively considered.Firstly,the typical explosion tests and collapse accidents of reinforced concrete(RC)structures and masonry walls were numerically reproduced to verify the reliability of the numerical simulation approach for masonry-infilled RC frame structures.Subsequently,the blast-resistant analysis of a typical three-story masonry-infilled RC frame structure was conducted under internal explosions of different charge weights(25-200 kg TNT),including the propagation of blast waves,structural damage,and scattering of infilled walls.Besides,the proposed high-efficiency assessment method exhibited four key characteristics:(1)the concept of mirror explosion source and the non-linear shock addition rules were combined to predict the internal blast loadings in central and adjacent rooms;(2)the damage degrees of structural and non-structural members,i.e.,beams,slabs,columns,and infilled walls,were determined by the equivalent single degree of freedom method;(3)the importance factor of members was considered and weighted to evaluate the damage degree of the room;(4)the influence of usage and location of each room on the damage degree of the building structure was considered.Finally,the proposed assessment method was employed to predict the aforementioned explosion scenarios.It derives that the RC frame structures exhibit slight,moderate,and severe damage under the explosions of 25,100,and 200 kg TNT,respectively.The predicted damage degrees are identical to the simulation results,while the calculation time is reduced by over 99％.Therefore,the proposed method possesses reliability and timeliness in damage assessment of building structures.
blast loadingsbuilding structuredamage assessment methoddamage and failure
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