Nicola Augenti

In-Plane Lateral Response of a Full-Scale Masonry Subassemblage with and without an Inorganic Matrix-Grid Strengthening System

A full-scale unreinforced masonry (URM) wall with an opening was tested under in-plane lateral loading. The wall was first subjected to monotonically increasing displacements until a moderate damage level was reached. The damaged specimen was then cyclically tested up to almost the same maximum drift attained during the monotonic test to investigate the effects of previous damage on its nonlinear response. Finally, the masonry wall was repaired with inorganic matrix-grid (IMG) composites and subjected to a cyclic displacement-controlled test up to a near-collapse state. Most of the observed damage developed in the spandrel panel affecting both lateral resistance and strength degradation. Rocking of piers governed lateral stiffness and hysteretic response, which was characterized by low residual displacements and recentering behavior. The comparison between the experimental force-displacement curves demonstrated that the IMG strengthening system was able to provide energy dissipation capacity to the spandr...

Nonlinear Behavior of a Masonry Subassemblage Before and After Strengthening with Inorganic Matrix-Grid Composites

Past experimental tests on a full-scale masonry wall with an opening evidenced the key role of the spandrel panel in the in-plane nonlinear response of the system. Recent seismic codes do not provide specific criteria to assess and to strengthen existing masonry spandrel panels with inorganic matrix-grid (IMG) composites. Numerical finite-element (FE) analyses are used to deepen the knowledge about the nonlinear response of masonry walls and the role of the IMG strengthening system. The comparison of experimental and numerical results contributes to the development of a simplified analytical model to assess the influence of the external reinforcement system on the in-plane seismic response of masonry wall systems. Some hints about the strengthening design that could change the failure mode from brittle shear to ductile flexure are given. Finally, a further enhancement of the IMG strengthening system is proposed to avoid the undesirable splitting phenomena attributable to compression forces and to exploit ...

Performance of School Buildings during the 2002 Molise, Italy, Earthquake

The authors inspected approximately 300 primary and secondary schools in 87 municipalities of Molise. About 40% were masonry structures, 40% were reinforced concrete (RC) frame structures, and the remaining 20% were a variety of structures. Almost all of them were built without seismic criteria and most had no more than three stories. In this paper we compare the distribution of the damage with the vulnerability classes. The collapses in San Giuliano di Puglia highlight the comparative vulnerabilities related to structural types, construction phases, and location.

Derivation of risk areas associated with high-pressure natural-gas pipelines explosions including effects on structural components

Derivation of Risk Areas Associated with High-Pressure Natural-Gas Pipelines Explosions Including Effects on Structural Components Paola Russo*, Fulvio Parisi, Nicola Augenti, Gennaro Russo Dipartimento di Ingegneria Chimica Materiali Ambiente, Sapienza Università di Roma, Roma, Italia Dipartimento di Strutture per l’Ingegneria e l’Architettura, Università degli Studi di Napoli Federico II, Napoli, Italia Dipartimento di Ingegneria Chimica, dei Materiali e della Produzione industriale, Università degli Studi di Napoli Federico II, Napoli, Italia paola.russo@uniroma1.it

Partial Collapse of an Ancient Masonry Church

The Church of San Giacomo at Spoleto, Italy, partially collapsed on November 23, 2010 during strengthening interventions. It was an ancient unreinforced masonry basilica that was completed in 1568 with the construction of two lateral aisles, an apse and a bell tower. The collapse involved the entire central aisle to the presbytery and the right lateral aisle. The author was appointed by the Judicial Authority to investigate causes and responsibilities of that structural collapse. This paper describes the collapse mechanism, the evidence emerged during site investigations and all phases of the investigation procedure. Graphical and photographical documents are reported and discussed to provide complete information on what happened and caused the accident.