A Case History: Seismic Analysis of the Retaining Wall of the Sacro Convento in Assisi (Italy)

The aim of the present work is to analyse the seismic behaviour of the retaining wall of the square in front of the Basilica di San Francesco at Assisi that during a long seismic crisis occurred in September 1997 suffered some damage. Static, pseudo-static and dynamic analyses have been carried out on four significant sections of the wall. The data for the analysis derive from the geometric survey of the structures, the survey of the state of the damage, the measurement of the rotation movements of the wall, the collection of stratigraphic and geotechnical data, as well as the accelerometric recordings of the seismic events using instruments that had been in operation on the structures of the “Sacro Convento” since 1995. Built during the first half of the 16th century, the wall is made of stone masonry, is about 93 m long, 4 m thick, and supports an embankment, the height of which varies between 9.0 m and 12.5 m. The wall is approximately 18 m high, and is under the ground also in the front part; it has a rectangular transversal section in the lower part and a T-shaped section in the upper part. It is built on calcareous rock, and supports a covered portico that is about 3 5 m high. In practice, the recorded accelerometric history coincides with the one at the base of the wall. Numerous seismic events were recorded from 4/9/1997 to 6/10/1997, three of which had a PGA exceeding 0.15g. The most evident movement suffered by the wall was a rigid rotation that caused a movement at the top of the wall greater than 20 cm

Influence of Soil-Structure Interaction on Seismic Response of Shear Buildings

The beneficial or detrimental effect of dynamic Soil-Structure Interaction (SSI) is a controversial issue. With reference to an idealized R/C shear building, a comprehensive comparison between the results obtained with a classical fixed-base analysis and a complete SSI analysis is provided in the present paper. The shear-type structure is modeled as generalized Single Degree Of Freedom (SDOF) system using the principle of virtual displacements. The foundation consists of surface square foundations resting on different soil conditions, consistent with the provisions of EC8-part I. SSI effects in the far-field of earthquakes was evaluated by direct application of the elastic pseudo-acceleration/displacement design spectra proposed in EC8, taking into account the change in natural period and damping of the soil-structure system. SSI effect in near-field area of earthquakes was analyzed using the computer program SASSI2000 (Lysmer et al., 1999), by means of a set of ten actual earthquakes recorded within a distance of 20 km from fault The proposed analyses can be easily used by consultants who want to face the task of SSI in an immediate and simplified manner, without devoting resources into complex analysis. The charts proposed in this paper could be incorporated in seismic guidelines

Il progetto PNRR presso l’Ufficio GIP-GUP del Tribunale di Milano: primi risultati e capacità di conseguire gli obiettivi 2026

Gli uffici giudiziari hanno stabilito specifici target da raggiungere grazie all’apporto degli addetti all’ufficio per il processo (AUPP) acquisiti grazie ai fondi PNRR. Questo articolo si concentra sulla sezione GIP del Tribunale di Milano, che per le particolari condizioni di criticità vissute nel 2020, ha visto una massiccia iniezione di personale aggiuntivo e un conseguente riassetto organizzativo. L’analisi mostra che tutti gli indicatori di performance appaiono nel 2022 in deciso miglioramento e che gli AUPP contribuiscono alla più rapida gestione delle fasi a cui sono assegnati. Nonostante questi buoni risultati, i target 2026 non saranno raggiunti: l’apporto degli AUPP non è infatti sufficiente a compensare le scoperture di organico e le carenze strutturali e tecnologiche dell’ufficio. Per conseguire l’impatto atteso dal PNRR – riduzione dei tempi di giustizia e eliminazione dell’arretrato – appare cruciale pianificare in modo integrato gli strumenti di policy e monitorarne l’implementazione, ponendo attenzione alla qualità dei dati a supporto della strategia organizzativa