Seismic Monitoring of a Retaining Wall in Reinforced Concrete Piles

The trend of using numerical simulations when designing buildings is growing with the availability of increasingly higher capacity computers and the prevalence of a performance-based design philosophy requiring accurate forecasts of structural movements under seismic stress. In cases where consolidated calculation procedures do not exist, these simulations often provide the only rational approach. There are many examples of this in the field of geotechnical engineering. However, the reliability of these forecasts depends on forming correct models of the problems, having advanced knowledge of subsoil characteristics, and most importantly, having valid calculation models which are proven through comparisons with well-documented case studies of full-scale construction projects. The need to “measure” the dynamic responses of structures has driven the scientific community to design and create different types of monitoring plans. Within this field of study, a seismic monitoring system has been installed for the construction of the "Casa dello Studente" (Student House) near the Campobasso campus of the University of Molise. The system consists of a retaining wall of reinforced concrete piles and the instrumentation consists of four inclinometer casings and eight customized accelerometer systems with two components installed inside two piles. This type of installation is one of the few examples of seismic monitoring on actual full-scale geotechnical works. Its purpose is to provide an interesting case study through which to calibrate simplified and complete calculation methodologies. The line of reasoning used to design and install the monitoring system is described in this article.