Impact of Surface Blasting on Underground Workings and Structures

Several underground mines are being worked at a depth of 30-150 m from operating surface mines. Under such conditions ground vibration from surface blasting may be a potential threat to the stability of adjacent underground mines. The book deals with a new innovative concept of classifying the blast induced damage to underground workings and structures due to surface blasts as ‘Severe’ ‘Moderate’ and ‘No damage’ by measuring the blast induced vibration. Predictor equations have been discussed to estimate ground vibration accurately and reliably. The advantages of the site-specific scaling law are discussed. The prediction efficacy of statistical tool has been compared with that of artificial network techniques. 144 finite element models of underground workings and structures using ANSYS-ANSA-LS_DYNA combined software have been developed and analysed. A new approach is proposed to classify blasting damage using the concept of ‘ Blast Damage Factor’ and linear discriminant functions. Site-specific charts between weight and distance have been developed so that blasting at a surface mine can be conducted without causing damage to adjacent underground mine workings and structures.