Seismic non-destructive testing on a reinforced concrete bridge column using tomographic imaging techniques

Abstract

This paper presents the results of a seismic non-destructive testing (NOT) survey on a reinforced concrete pier cap of a bridge column using tomographic imaging techniques. The velocity and attenuation tomograms were obtained to inspect the floor of the pier cap. The pier cap block is the critical part of a pre-stressed reinforced concrete bridge. The propagation velocity tomogram revealed that the average P-wave velocity is about 3450 m s-1. The attenuation tomogram showed an average value equivalent to ∼ 1 dB m -1. Both tomograms showed similar spatial distribution and implied that the solidification of most of the reinforced concrete of the pier block was quite uniform. Zones of relatively lower velocity and higher attenuation were found in the corners and the two opposite sides of shorter length. Direct invasive drilling into the problematic locations of the floor found relatively poorer solidification, supporting the interpretation of the non-destructive tomographic imaging. © 2005 Nanjing Institute of Geophysical Prospecting.