拱形结构爆炸作用荷载分布规律研究

采用数值计算方法对地下高边墙拱形结构在爆炸作用下爆炸荷载的分布规律进行了研究。研究结果表明，拱形部分荷载分布主要受爆高、跨度、观测点角度的影响，荷载分布形式是以拱顶为对称轴的马鞍形。爆高与跨度的比值越大，结构上的荷载分布越均匀，反之，则越集中；边墙部分荷载分布主要受爆高、跨度、边墙高度影响，从墙顶开始沿着墙体逐渐衰减，最终趋于均匀。在此基础上，给出了自由场地下大跨度拱形结构荷载的计算方法，并计算了拱形结构上的荷载系数，发现沿着拱形荷载系数并不是固定值，在拱顶最小，近似等于1.5，且随拱角的增加而变大。

Research on distribution laws of blast load on arch structure

Distribution laws of blast loads on arch structure induced by underground explosions are studied by numerical method. The results show that the load distribution on arch is mainly effected by the explosion height, the arch span and the angle of monitoring point. The distribution form of load is shape of saddle as a symmetry axis around vault. Load distribution on the arch will be more uniform with the increase of the ratio of explosion distance and span. Conversely, it will be more concentrated. The load distribution on side-wall is mainly effected by the explosion height, the arch span and the side-wall height; and it reduces gradually from wall tip along the wall, finally tends to even distribution. On this basis, a method to calculating load on arch structure with large span is proposed. After calculating the load factor on arch structure, it is found that the load factor around the arch is not a constant value and increases with the increase of arch angle. The minimum value of the factor appears at the vault and it equals to 1.5.