Structural monitoring with GPS and accelerometers: the chimney of the power plant in Piacenza, Italy

The construction industry is increasingly involved in the safety assessment and survey of existing structures, often following refurbishment and structural modification works. The increasing difficulty in selecting building areas and getting funding for new constructions, jointly to the not negligible costs related to the demolition of the old ones as well as to the costs for the following site clearance, has led to a greater environmental awareness and to a cultural desire to maintain ancient and historic structures. The Italian Centre for Experimental Electric Science (CESI) and Politecnico di Milano set up a monitoring system aimed at the detection of structural modification of slender structure in near real time. The system, installed on a 120 m high chimney of the Piacenza (Italy) power plant, acquires data at a frequency of 10 Hz from 3 GPS (one rover on the chimney, connected to the acquisition and processing unit by a WI-FI system, and two masters) and, at a frequency of 125 Hz, from 4 accelerometers. The paper reports on the acquisition system, explains the data analysis procedure as well as the results of the measurement campaign, three months long.