爆破掘进下隧道初期支护的动力响应特征将影响施工安全和进度。为研究不同因素下隧道初期支护爆破动力响应特性，结合林场隧道爆破工程，采用现场监测、数值模拟相结合的方法，分析龄期、进尺长度及起爆时间间隔影响下隧道初期支护的振速和应力分布规律，并引入Morris筛选法对各因素影响程度进行分析。结果表明，不同进尺长度、龄期、起爆时间间隔下，隧道初期支护峰值振速均呈现V_y ＞V_z ＞V_x （V_x 、V_y 、V_z 分别代表x轴、y轴、z轴方向的峰值振速）规律，所受拉应力均远大于剪应力；1~3 d龄期内初期支护的振速及应力变化剧烈，7 d后逐渐趋于平缓，衰减速率x轴最大、z轴次之、y轴最小；随进尺长度的增加，质点振速增长率呈现y轴最大，x轴与z轴次之；起爆时间间隔为5 ms时，应力波相互抵消，振速呈现下降趋势；3种因素对结构爆破动力响应特征的影响程度由大到小为进尺长度、龄期、起爆时间间隔。研究结果可为类似隧道爆破工程提供参考。

The dynamic response characteristics of the initial support under blasting will affect the construction safety and schedule. In order to study the dynamic response characteristics of tunnel initial support under different factors， combined with the tunnel blasting project of forest farm， the vibration velocity and stress distribution laws of tunnel initial support under the influence of age， footage length and detonation time interval were analyzed by combining field monitoring and numerical simulation， and Morris screening method was introduced to analyze the influence degree of each factor. The results show that the peak vibration velocity of the initial support presents V_y >V_z >V_x rule under different penetration length， age and detonation time interval， and the tensile stress is much larger than the shear stress. The vibration velocity and stress of the initial support change sharply during the age of 1-3 d， and gradually tend to be flat after 7 days， the attenuation rate of the x-axis is the largest， followed by the z-axis， and the y-axis is the smallest. With the increase of footage length， the growth rate of particle vibration velocity presents a rule of the y-axis is the largest， followed by the x-axis and the z-axis. When the detonation time interval is 5ms， the stress waves cancel each other and the vibration velocity decreases. The degree of influence of the three factors on the dynamic response characteristics of structural blasting is in the order of footage length， age， and blasting interval. The research results can provide reference for similar tunnel blasting projects.