爆炸作用下地下岩石结构界面反射参数探讨

地下结构反射系数定义为反射场峰值应力除以入射场峰值应力,是确定结构表面荷载分布的重要参数。本文从波的界面效应出发,运用岩土介质与结构相互作用原理,考虑波与介质的耦合效应,重点探讨了地下结构界面反射机理。运用有限元参数变化法,系统地探讨了参数变化对反射系数影响。首先,考虑不同爆源参数特性: 如比例爆距、爆炸当量、爆炸偏角等对界面反射的影响;其次,变化传播介质参数特性,如相对密度、相对弹性模量、相对泊松比对界面反射的影响;最后,变化结构特性参数,探讨不同结构型式和尺寸下的反射系数。研究表明,爆源参数、介质参数和结构参数均对界面反射有影响,各参数影响程度不同。

Discussion on Reflection Coefficient for Buried Rock Structure Subjected bo Explosive Load

The reflection coefficient of buried structure is defined as the peak value of free field divided by the peak value of reflection field, and it is an important factor to determine the blast load around the underground structure. Considering the interface effects, i.e. interaction between the medium and structure and interaction between blast wave and medium, the paper discusses the reflection mechanism of the underground structure interface. By altering finite factors, the paper discusses the effect of factor variation on reflection coefficient systematically. At first, considering the influence of the characteristic of some factors for the explosion source on interface reflection, such as ratio distance, explosion equivalent, explosion angle etc. Secondly, by alternating medium characteristics i.e. relative density, relative elastic modulus, relative Poisson’s radio, discuss the change of the reflection; At last, by alternating structure characteristics, i.e. shape and size of the structure, the change of the reflection is discussed. From the research result, characteristic of the explosion source and the medium, and also shape and size of the structure more or less influence the reflection coefficient.