METODO INNOVATIVO PER LA PREARMATURA IN AVANZAMENTO ED IL RINFORZO DEL FRONTE CON TUBI IN ACCIAIO AUTOPERFORANTI PER LA COSTRUZIONE DI UNA GALLERIA IN SABBIE INSTABILI SULL'AUTOSTRADA SA-RC

Due nuove gallerie automodali gemelle, lunghe circa mille metri, sono in corso di costruzione per sostituire quelle in esercizio, seriamente compromesse dall'instabilità del terreno ed ormai troppo piccole per il volume di traffico in sviluppo. Il terreno ospitante è un'alternanza caotica di strati variamente ripiegati di sedimenti marini fini, da sabbie a sabbie limose ed argillose, con variabile presenza d'acqua. La totale instabilità del terreno, nel quale non rimangono aperti nemmeno i fori per i consolidamenti ha reso necessario un rinforzo continuo della calotta ed il consolidamento del fronte di scavo. A tale scopo è stato messo a punto un sistema innovativo di consolidamento e rinforzo (Metodo Pelizza 2) che prevede l'impiego sia in corona che al fonte di tubi autoperforanti in acciaio iniettati in corso di perforazione alla pressione di 200 bar con boiacca di cemento lievemente espandente. Nel testo sono forniti dettagli del metodo e dei tempi operativ

Engineering Reconnaissance following the October 2016 Central Italy Earthquakes. Version 2. Editors Paolo Zimmaro and Jonathan Stewart, Geotechnical Earthquake Engineering Reconnaissance GEER Association, Report No. GEER-050D

A team from the Geotechnical Extreme Events Reconnaissance (GEER) Association, supported by the National Science Foundation, has been mobilized to investigate geotechnical and geological aspects of the destructive earthquake sequence that occurred in Central Italy during a series of significant events October 26-30, 2016, which followed prior events August 24-29, 2016. GEER responded to the initial event sequence and reports resulting from that effort are published on the GEER web site. As before, GEER will operate in close collaboration with Italian engineers and scientists. GEER is also coordinating its reconnaissance activities to coincide with those of EERI, which will be led by Dr. Silvia Mazzoni. Giuseppe Lanzo, Professor at Sapienza University of Rome, and Jonathan P. Stewart, Professor and Chair of the Department of Civil and Environmental Engineering at UCLA, are the GEER team co-leaders. The US-based GEER team members participating in the investigation are Prof. Kevin Franke (Brigham Young University), Dr. Robert E. Kayen (US Geological Survey and UCLA), and Dr. Bret Lingwall (South Dakota School of Mines and Tech.). The GEER team is part of an international coordinated effort that involves cognizant Italian agencies (i.e. National Institute of Geophysics and Vulcanology, INGV; Rete dei Laboratori Universitari di Ingegneria Sismica, ReLuis; and European Centre for Training and Research in Earthquake Engineering, EUCENTRE Foundation and Italian Center for Seismic Microzonation and its Applications). Key Italian participants include: Prof. Luigi Di Sarno (ReLuis and University of Sannio), Profs. Sebastiano Foti and Filiberto Chiabrando (Politecnico di Torino), Dr. Fabrizio Galadini, Emanuela Falcucci, and Stefano Gori (INGV), Prof. Alessandro Pagliaroli (University of Chieti-Pescara), Dr. Giuseppe Scasserra and Prof. Filippo Santucci de Magistris (University of Molise), Prof. Francesco Silvestri (University of Napoli Federico II), Prof. Stefano Aversa (University of Napoli Parthenope) and MrDr. Paolo Tommasi (Consiglio Nazionale delle Ricerche, Rome). Also contributing to the GEER effort are researchers from New Zealand (Dr. Fernando Della Pasqua, GNS Science) and United Kingdom/Greece (team led by Prof. Anastasios Sextos, University of Bristol and Aristotle University of Thessaloniki). A full list of GEER team members will be compiled following deployment to the field. The GEER team assembled for this effort is multi-disciplinary, including geology, seismology, geotechnical engineering, structural engineering, and geomatics. Based on information gathered to date, field investigations for the GEER team and collaborators have focused on: (1) substantial surface fault rupture, apparently on the Mt. Vettore fault, (2) major rockfalls and landslides, including a large slide that dammed a river; and (3) building, bridge, and other infrastructure performance in villages and hamlets throughout the region, including many that had been well documented in reconnaissance following the 24-29 August event sequence. Earthquake engineering is an experience-driven field in which perishable data that can be used to advance our understanding should be systematically collected. The data collection will be performed using traditional mapping/observational methods and advanced imaging tools