接触爆炸荷载对钢筋混凝土梁的局部毁伤效应

为得到接触爆炸下钢筋混凝土（reinforced concrete，RC）梁的局部破坏模式和毁伤效应，对同一尺寸的RC梁进行了不同装药量的接触爆炸试验研究。试验中采用框架结构中典型工程尺度RC原型梁为研究对象，通过4次爆炸试验，观测了RC梁在不同装药量下的局部破坏模式和破坏特征，分析了装药量对局部毁伤效应的影响。研究结果表明：接触爆炸荷载作用下，RC梁将发生正面成坑、侧面崩落、背面震塌和截面冲切等局部破坏模式，爆坑深度、震塌厚度、表面毁伤面积以及受压区纵筋变形均与装药量立方根近似呈线性增加关系。在试验数据基础上，将RC梁局部毁伤程度划分为轻度毁伤、中度毁伤、重度毁伤和严重毁伤4个等级，采用比例装药量判据进行评估。研究成果可为抗爆结构设计和结构毁伤评估提供理论依据。

Local damage effects of reinforced concrete beams under contact explosions

In order to investigate the local failure modes and damage effects of reinforced concrete (RC) beams under contact explosion, the experimental studies of RC beams with the same size under different TNT charge masses were conducted. In the tests, the typical engineering scale RC prototype beams designed for frame structures were used as research objects. Through four independent explosion tests, the failure modes and damage characteristics of the RC beams were observed at different TNT charge masses, and the influence of different TNT charge masses on the local damage was analyzed. The results show that RC beams undergo four types of local failure modes such as front crater, side breakdown, back collapse and section punching under contact detonations. The depth of crater, thickness of the spallation, surface damaged area, and the deformation of the steel bars exhibited a linear increase with the cubic root of TNT charge masses. Based on the experimental data, the local damage degree could be divided into four grades: slight, moderate, serious and severe, that could be evaluated by the proportional charge criterion. The research results can provide a theoretical basis for designing the anti-blast structures and assessing the damage of components subjected to explosive loading.