Clinker storage silos: Validation of dynamic performance through measurements and finite element simulation

Abstract

The paper describes the design and application of a structural health monitoring system aimed at analysing the dynamic response of reinforced concrete silos for the storage of clinker. The in-situ dynamic measurements, supported by finite element simulations to assess the structural safety, were prompted by reports from people working in facilities near the silos in question, who complained of strong vibrations. The proposed approach combines the advantages of theoretical and operational modal analysis based on monitoring during normal use of the silos, including their emptying. The measurements were performed automatically and continuously over time, and only significant events, like shocks caused by clinker masses falling off the side walls of the silos, were saved into the remote server as the acceleration-time waveforms. They were registered with 4000 Hz frequency by piezoelectric accelerometers mounted on the bottom of the silos within the support structure. The data management system with predefined post-processing algorithms allow to extract dynamic parameters of the structure, which were then used to validate the spatial finite element model (FEM). What is worth underlying, the analysis took into account different degrees of filling of the silos, as these directly affect the dynamics of the structure. The results described hereafter were the basis for providing expertise on structural safety. The presented case study is an example of how automatic monitoring over a specified period of time can assist engineers in making rational decisions.