Vibration effects on underground concrete structures

When performing blasting operations in open pit settings, energy is released and transmitted through the geological structure. Some negative effects can significantly impact mining operations and can adversely affect mine production. This thesis presents recommendations for blast design to prevent damage on adjacent concrete structures of underground operations due to ground motion resulting from blasting. The work includes a summary covering currently accepted views of blasting vibration measurements, human response to blasting, and criteria for wall damage control as background information. This is followed by sections on vibration level estimation and blasting techniques to control vibration, a section on structural dynamics of reinforced concrete structures subject to ground motion, and a case study describing a problem regarding an open pit mine expansion and whether production blasting will damage the concrete shaft structure due to blast-induced ground motion.;Based on the results, a set of criteria is provided to implement in current and future surface mining operations that involve blasting near underground concrete structures. A set of techniques on how to improve vibration levels for safe operations is presented. Knowledge of particle velocity and wave propagation for site-specific circumstances to determine a safe level of vibration is recommended. A set of criteria to implement a monitoring plan to prevent structural damage of underground concrete structures near surface mining operations is provided. Emphasis is placed in making use of electronic detonators and early delay detonators to achieve successful levels of vibration. A dynamic analysis is necessary to determine if vibration from blasting can damage the concrete shaft structure. Determining the vibration frequency is key to analyzing the response of the structure, not only to static loading but also dynamic loading.