Field monitoring of piling effects on a nearby masonry vault using distributed sensing

This paper presents a recent case study of monitoring the effects of piling on an adjacent old masonry vault in London. The monitoring scheme consists of 3 independent instrumentation sets that provide different types of information: (a) discrete total station point targets, (b) linear distributed fibre optic cable sensors and (c) surface distributed laser scanners. The availability of these sensors is able to shed some light on the actual response of the masonry structure through precise displacements and high-accuracy localised strains. The collected monitoring data show the location of cracks and provide indications for their opening magnitude. Relevant numerical analyses have also been conducted using (a) limit analysis mechanisms and (b) finite element deformation analysis which confirmed the observed field deformation mechanism and the presence of cracks within the structure. It is shown that such innovative sensing approaches can provide valuable detailed information about the real behaviour of structures that were not available before.