Abstract:
Blasting excavation is an important construction method to improve the efficiency of canal channel expansion, but the blasting vibration effect caused by it may have adverse effects on the substructure of existing waterways. In order to clarify the dynamic response characteristics of the bridge substructure under the action of blasting excavation vibration, this paper analyzes the stress and vibration velocity distribution characteristics of the adjacent bridge substructure under the influence of blasting based on the Pinglu Canal channel expansion blasting project and the finite element numerical simulation method verified by field test. Based on the maximum tensile stress criterion, the safe vibration velocity threshold of the bridge substructure is proposed. The results show that the maximum tensile stress is generated at the junction of bridge pile foundation and cap under the vibration of canal blasting excavation. The parts with large vibration of the substructure are mainly located in the pile foundation. The allowable vibration velocity of the substructure of the bridge with the cap as the monitoring point is 3.2 cm·s-1.
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