Concerning on the blasting excavation of division pier where free face has formed as one side of the deep trough was excavated

in order to study the effect of blasting on the division pier

dynamic responses of vibration

stress and displacement of the division pier were analysed under blasting impact load. In addition

both the blasting excavation way was improved and the excavation procedure was optimized. The study shows that the division pier dynamic responses under blasting impact load are caused by the reflection and superposition of blasting stress wave. So selecting proper reserved rock thickness could reasonably utilize this reflection and superpositon to impair dynamic responses of the division pier under blasting impact load and consequently the resulting dynamic unstability risk is also reduced. This research result has guiding significance on engineering practice.