Investigation of damage on wall panels due to blast vibration

Abstract

As the energy left over from a blast vibration process transmits to the surrounding, waves displace particles in their paths giving rise to particle velocities. However, the damage occurs which depends on the received structural vibration, may vary according to the soil type, soil structure interaction and characteristics of a structure. In Sri Lanka, various threshold values of blast vibration are being used although still many complains are raised on damages to structures due to blasting activities. It is necessary to understand whether all of the cracks have been induced due to the blasting activity as in some situations, the blast vibration test results were within the allowable limits. This paper presents a study on investigating the damage on wall panels due to blast vibration. Location for the construction of the experimental model structure was selected from the initial site investigation and the vibration level measurements at different locations. The initial test carried out has shown that the soil structure interaction should be strong enough to obtain the ground vibrations. A wall panel, size of 1200 mm×1000 mm with free ends, was constructed closer to a rock blasting quarry and the effect of vibration on the structure was monitored. A significant crack was observed at the foundation level of the wall panel at a vibration level around 30mms-1 of ppv. Along with the experimental method, numerical modeling was carried out with the Finite Element Modeling using SAP 2000 software. Results of the numerical study also verify that the tensile stresses of the bottom level of the wall panel exceed the splitting tensile strength.