爆炸作用下地下直墙拱结构动荷载分布规律试验研究

为研究集中装药爆炸条件下地下直墙拱结构被覆段的荷载分布规律，通过野外抗爆模型试验测试土中自由场应力以及拱结构表面各点荷载的应力时程曲线。采用数据拟合与归一化方法，得到拱结构横断面及纵断面的荷载峰值分布规律包络图，并将测试结果与理论方法、数值手段的研究结果进行对比验证。结果表明，地下拱结构承受的动荷载与理论方法、数值手段得到的基本规律一致，呈类三角形分布。根据荷载分布情况，结合荷载作用面积的等效原理，提出局部动载的简化计算公式，给出地下拱结构抗化爆的荷载计算步骤。

DYNAMIC TEST OF INTERFACE STRESS DISTRIBUTION ON A BURIED STRAIGHT-WALL ARCH STRUCTURE SUBJECTED TO BLAST LOADS

For sake of disclosing dynamic loading distribution on straight-wall arch lining，the time-history curve of free field stress and the radial interface loading on the arch structure in soil are measured through field model test which subjected to blast loads. Through data fitting and normalization method，the envelope diagram of peak loading distribution on cross and longitudinal sections of arch structure are obtained. The results of theoretical and numerical methods are verified and compared with the measured loading distribution law. Results show a good agreement between experimental data and theoretical calculation and finite element computation. The dynamic loading on buried arch structure approximates a triangular distribution. Making use of equivalent principle of load distribution scale，a simplified linear function of local dynamic load is proposed and the loading calculation procedure of buried arch structure anti-blast loading is developed.