重要建筑结构抗恐怖爆炸设计爆炸荷载取值探讨

Research on blast load value in design of important building structures against terrorist explosions

由于爆炸过程的不稳定和爆炸测试的不确定性,由已有的预测爆炸荷载的经验公式和图表所得到的爆炸荷载存在较大差异,不便于工程应用。在查阅了各国抗爆规范和大量文献,搜集了大量已有的经验公式和图表的基础上,分析和计算了不同比例距离下的反射超压和假想比例持续时间。运用统计学方法求得各比例距离下具有90%保证率的反射超压和假想比例持续时间,拟合得到了爆炸荷载反射超压及假想比例持续时间与比例距离的关系曲线,可用于确定建筑结构抗爆设计的爆炸荷载取值。拟合公式确定的爆炸荷载参数稍大于人防规范和UFC规范中的规定取值,偏于安全,较为合理。

Since the explosion process is very unstable and there are many uncertainties involved in the blast tests, there is a big difference between the existing empirical formulae and the charts in predicting the blast loads. It is not convenient for the application in engineering practice. A lot of existing empirical formulas and charts are collected from the blast resistant design codes of various countries and a large number of references. Then the reflected overpressure and the fictitious scaled duration at different scaled distance are calculated and analyzed through these formulas and charts. The reflected overpressure and fictitious scaled duration with 90% confidence level at different scaled distance are then obtained based on the statistical methods. Finally the empirical equation for the reflected overpressure-scaled distance curve and the fictitious scaled duration-scaled distance curve are derived through the curve fitting method, which could be used to define the blast loads in the blast resistant design of building structures, his found that the blast load parameters defined by the fitted equation are a little bit larger than those from the code for design of civil air defense basement and the UFC guidelines. This indicates that the fitted equation is safe to be used in the blast resistant design and is reasonable to be applied to engineering practice.