ANALYSIS OF THE DAMAGE STATE OF A MONUMENTAL BUILDING BY CONSIDERING THE VARIATIONS IN SOIL CONDITIONS

This paper investigates whether it is possible to identify the influence of soil conditions on the modal parameters of the structure for damage detection and overall structural health monitoring. To do so, the data gathered on a large monumental building damaged by differ-ential settlements are analyzed. In particular the dynamic response of the case study, a large monumental masonry building, was experimentally investigated within an operational modal analysis (OMA) campaign. Mechanical data obtained from the geophysical tests were in turn employed to build and characterize a numerical model of the soil underlying and sur-rounding the building. The resulting model was then used to study the sensitivity of the mod-al charasteristics of the building with respect to variations of external environmental factors (e.g., the water table level) which affect the underlying soil. The results obtained from this numerical study is deemed to represent a starting point for future experimental tests and investigations, whose final aim is relating ambient vibration measurement to the occurrence of differential settlements or subsidence, in order to detect progressive, and possibly pathological, behaviors

Combining satellite geophysical data with continuous on-site measurements for monitoring the dynamic parameters of civil structures

One key issue in the Structural Health Monitoring (SHM) of buildings is the influence of the soil on the dynamics of the system. The lack of accurate information on soil-structure interaction represents a source of significant uncertainty and generates difficulties in assessing the state of structural health. In this respect, satellite data could represent a valuable tool for soil knowledge. This paper presents the first study of satellite data coming from the environmental Copernicus program of the European Space Agency (ESA) for the alternative application in the field of SHM. In particular, Land Surface Temperature (LST) and Soil Water Index (SWI) data are elected to study surface temperature and moisture condition of the soil. Once examined and processed, these records have been statistically analyzed, crossed with on-site experimental quantities (natural frequencies and environmental variations), and given as input to a Finite Element (FE) model. The final goal is to understand the actual structural behavior, but also to monitor the evolution of the dynamic parameters for the purposes of structural and seismic monitoring. The largest oval masonry dome in the world was chosen as a prominent case study to demonstrate this novel approach to SHM