Prediction of shear strain induced by blasting waves in surface structures based on coupled frequency, velocity, and displacement effects

Abstract

Blasting ground vibration is an undesirable side effect of using explosives to fragment rocks. There is not any universally accepted standard to determine limitations of blast vibrations; however, velocity is the most commonly used method to measure ground vibrations. Because the structural response is highly frequency dependent, the frequency content is an essential characteristic of blast-induced shock waves along with the velocity. The magnitude of blast-induced displacement or velocity and their relative stress and strain are directly related to the quantity of charge, distance from blasting point, and geological conditions. These effects were not considered in the response spectrum theory of structures. This article tries to propose a new procedure to predict the shear displacement and relative strain for optimization of blasting patterns before the explosion. It can be accomplished by representing the effects of both velocity and frequency on the horizontal displacement of the structures based on measurements undertaken by the authors in two different rock formations. In this study, collected data were analyzed statistically to determine the coupled effects of dominant frequency, peak particle velocity, and peak particle displacement to propose a simple procedure for predicting the range of blast-induced displacement and related strain in structures.