2016 – Assessing Blasting Impacts on Embankment Dams: Limitations with Adopting an Equivalent Earthquake Approach

Robert Harrington

There is a significant body of knowledge in relation to assessing the impacts of earthquakes on earth and rock fill dams which has led to a number of widely recognised and accepted methodologies for the calculation of potential deformations from an earthquake event. However, limited research has been conducted into the assessment of blasting impacts on earth structures. This has led to an adoption of earthquake analysis methods in the assessment of blasting impacts on earth structures without adequate consideration to the difference between the stresses and displacements imposed on an embankment as a result of a blast as opposed to an earthquake. Adopting earthquake analysis techniques may result in conservative vibration limits being imposed when undertaking blasting near embankment dams which may have negative financial impacts.

This paper explores the risks associated with blasting adjacent to earth fill dams and details the difference between stresses and displacements imposed on an embankment by a blast versus an earthquake.

This paper also discusses previously adopted approaches to assessing potential impacts associated with blasting and the limitations associated with adopting a pseudo-static and simplified permanent deformation analysis for blasts modelled as equivalent earthquakes. Finally, the paper proposes an alternate risk based analysis approach.