Capturing the effects of remedial trenching through acoustic imaging

Abstract

When remedial trenching occurs on a buried cable, is it truly known and understood what happens to the cable? Does the cables depth of lowering increase, and are there any potential issues introduced to the buried cable? Previously, any results that varied from the expected had to be accepted and assumptions as to why these results occurred were made without truly understanding the reasons why. Or alternatively, the results obtained were deemed as being unlikely and disregarded. In this example, to accurately capture the effects of remedial trenching, a volumetric multiple acoustic aspect image of the remedial trenched sections of 40 cables, with a combined distance of 14.076 km was acquired. This revealed the characteristics and interactions within the shallow soils both before and after remedial trenching, which found on average that a 0.1 m increase in cable depth was achieved. However, it was found that remedial trenching also has the potential to introduce new issues with the buried cable.