Comparative study on tunnel blast-induced vibration for the underground cavern group

Seismic wave induced by blasting excavation of tunnel may exert adverse effects to the surrounding rock. To study the different characteristics and attenuation of blast-induced vibration in the blasting tunnel and adjacent tunnel, field blasting tests are carried out to record velocity–time histories during blasting in Wanhua Underground Gas Storage. The characteristics and attenuation of vibration velocity and energy are presented based on the field data. And the dynamic finite-element model is established to further study the vibration attenuation law. Results demonstrate that PPV and vibration energy of the adjacent tunnel is greater than that in the blasting tunnel and attenuates more readily when monitoring points are near the blasting area. The dominant frequencies of the adjacent tunnel are higher than that in the blasting tunnel at three orthogonal directions. Adopting vibration energy as the evaluation index of seismic intensity, the fitting formula has favorable prediction accuracy, which will provide more accurate guidance for controlling the adverse effects of tunnel blasting.