高饱和黏性土中爆炸波作用下直埋钢管（空管）动态响应

设计和实施了系列爆炸波作用下钢管的动态响应实验，获得了管道应变、振动速度和加速度及地表振动速度的时间历程。分析实验数据可知:在爆炸波近中场，峰值应变大小同管土相对刚度因数负相关，并随比例距离呈幂函数形式衰减，且在爆炸波不同分区衰减指数不同；地表峰值粒子速度、各管的峰值振动速度和测点峰值应变之间具有良好的线性关系。对各测试量做FFT (Fast Fourier Transformation)频谱分析得:振动信号主要集中在低频段，质心频率在10～60 Hz范围内，频谱同天然地震波谱有明显差异，动应变谱质心频率随药量增加亦呈幂函数形式衰减；考虑了爆腔因素以后，管道和地表振速频谱的质心频率和比例距离取对数后具有线性衰减关系。实验所得数据可应用于相似条件下管道的抗震计算，一些结论可作为深入研究爆炸波作用下埋地管道冲击振动机理的依据。

Dynamic responses of hollow steel pipes directly buried in high-saturated clay to blast waves

A series of experiments were designed and implemented to explore dynamic responses of steel pipes to blast waves The time histories of dynamic strains, vibration velocities and accelerations of the steel pipes were obtained, and the vibration velocity-time curves were gained. It is known by analyzing the experimental data that in the near and middle fields of the blast wave, the peak dynamic strains are negatively correlated with the relative stiffness coefficient of the pipe and the soil, and they follow the attenuation law of the power function with scaled distance; that the attenuation indexes are different for the blast wave propagating in the different sections of the field. The peak particle vibration velocities of the ground and the pipes have good linear correlations with the peak strains of the measuring points at the pipes. On the basis of the spectrum analysis by the fast Fourier transform on each test quantity, it is found that the spectrum energy of each test quantity is mainly concentrated in the low-frequency band, the centroid frequency is in 10?60 Hz, but there are obvious differences compared to the spectra of natural seismic waves. The centroid frequency of the dynamic strain spectrum is decayed in the exponent form of a power function with the increase of the explosive charge. By taking logarithm, there is a linear attenuation relationship between the scaled distance and the centroid frequencies of velocity spectra that the blasting cavity factor is considered. The test data can be directly applied to the seismic calculation under similar conditions, and some conclusions can be used as the theoretical basis for further study of the impact damage mechanism of buried pipelines.