土中浅埋地下拱结构化爆动载的确定方法

为了研究化爆作用下地下拱结构表面荷载分布的规律,简述了目前化爆条件下结构上荷载均布化的3种方法,提出了适用于地下拱结构抗爆设计的荷载分布假设,即拱结构横截面上荷载呈三角形分布,且纵向荷载均布。通过有限元数值模拟,比较分析了4种工况动载峰值荷载作用下拱结构在弹性阶段、塑性阶段的受力状况和结构响应,并与动荷载作用下的结构响应进行对比分析。结果表明,相较于化爆条件下拱结构所受圆锥状荷载,把化爆条件下拱结构所受荷载假设为横截面上三角形分布、沿纵向均匀分布时,拱结构响应相似;按荷载总集度相等原则提出的荷载简化方法仍偏于保守,可以作为一种用于工程设计的简化计算方法。

Engineering simplification for chemical explosion loads on shallow buried arch structure surface

A review of three existing load uniformity methods was presented to study the distribution of surface load of underground arch structure under chemical explosion loads, thus providing a reference for engineering structural design and calculation. Then the load distribution assumption was proposed,i.e. the peak dynamic load on the cross-section of arch ring distributes as a triangle, while on the longitudinal section approximating uniformly. The suggested load distribution assumption is suitable for underground arch structure subjected to blast loads. Through finite element numerical method, arch structural behaviors were preliminarily analyzed under four peak static loads. Displacement and stress of the critical points on arch structure were calculated at elastic/plastic stage, respectively, and compared with the structural responses under dynamic load.The results show that,compared with the conical loads, assuming the peak dynamic load on the cross-section of arch ring distributes as a triangle while on the longitudinal section approximating uniformly, the responses of the arch structure are similar. Based on total pressure equal principle, the simplified method is still conservative, which can be used for engineering structural design.