A surface blast generates both air pressure and ground shock on structures. Studies on the relative effects of the air pressure and ground shock on the responses of structures are meagre. In the present study, a preliminary estimate of the relative contributions of the ground shock and air pressure on building responses due to a surface blast is obtained by using an equivalent single-degree-of-freedom (SDOF) model. For this purpose, both linear and non-linear analyses of SDOF models of four reinforced concrete building frames of different heights are performed under different blast scenarios by varying the standoff distance and charge weight. In addition, the criticality of the surface blast in comparison to the free air blast is investigated with the help of the same SDOF models. The study reveals that the contribution of the ground shock is less than that of the air pressure on the responses of low-rise buildings. For high-rise buildings, the opposite trend is observed for smaller standoff distances (R < 15 m). Further, it is shown that the surface blast is more critical as compared to the free air blast for shorter buildings (fewer than six storeys), but the opposite holds good for taller buildings.

中文翻译：

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估计表面爆炸对建筑物的影响

表面爆炸会在建筑物上产生气压和地面冲击。关于气压和地震动对结构响应的相对影响的研究还很薄弱。在本研究中，通过使用等效的单自由度（SDOF）模型获得了地震动和气压对建筑物因表面爆炸而产生的响应的相对贡献的初步估计。为此，在不同爆炸场景下，通过改变间隔距离和装料重量，对四个不同高度的钢筋混凝土建筑框架的SDOF模型进行了线性和非线性分析。此外，借助相同的SDOF模型，研究了表面爆炸与自由空气爆炸相比的临界度。研究表明，在低层建筑物的响应上，地震动的贡献小于气压的贡献。对于高层建筑，相反的趋势是较小的对峙距离（R  <15 m）。进一步地，表明对于较短的建筑物（少于六层），与自由风相比，表面爆炸更为关键，但是对于较高的建筑物则相反。