
Gerardo Mario VerderameUniversity of Naples Federico II | UNINA · Department of Structures for Engineering and Architecture
Gerardo Mario Verderame
PhD
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Publications (303)
Knowledge, preparedness, prevention, and mitigation of seismic risks are central to the work of numerous scientific and engineering communities in Europe and beyond, driven by the significant loss of life, property, and infrastructure experienced in recent decades. In the face of ongoing disruptive climate changes, both natural and human-induced ha...
The existing Reinforced Concrete (RC) buildings stock is often characterized by a significant seismic vulnerability, due to the absence of capacity design principles, even in regions with high seismic hazard, such as Italy. Approximately 67% of existing RC buildings in Italy have been designed without considering seismic actions (GLD), resulting in...
Dear Colleagues and Friends,
I’m pleased to announce that at the international conference COMPDYN 2025 that will be held in Rhodes, Greece, we are organizing the mini-symposium titled “Advancements in seismic vulnerability assessment: toward an integrated disaster risk governance”.
The mini-symposium’s Organizers are Dr. Carlo Del Gaudio (Univer...
Existing Reinforced Concrete (RC) buildings in seismic-prone areas typically show very poor seismic performance. One of their major issues is related to shear failure in RC columns, generally characterized by a very low amount of transverse reinforcement, or in beam-column joints, almost always totally lacking stirrups. This kind of structural defi...
Masonry infills in Reinforced Concrete (RC) frames often strictly interact with the surrounding structural elements and significantly modify the response of the RC frame itself under lateral loading. The lumped action of the infill panel can produce a significant shear damage on the surrounding RC members. Such a phenomenon, hereinafter referred to...
In this study, heuristic vulnerability model is presented providing damage distribution as a function of ground motion severity, through the use of given distribution function.
Firstly, observational damage distribution are obtained from data collected after the recent earthquakes occurred in Italy and made available by DPC through Da.D.O. platform...
The seismic assessment of reinforced concrete (RC) structures is commonly carried out neglecting potential previous damage induced by other phenomena, for example those related to the actions of slow-moving settlements. Many efforts are dedicated by the research community in properly considering multi-hazard actions and their inter-relations on the...
This study investigates the seismic response of Reinforced Concrete (RC) framed buildings designed for gravity loads only, as very common in the Italian residential building stock before 1970. In particular, starting from the same building configuration (both in plan and elevation), the attention is mainly focused on the evaluation of the role of s...
Modern building codes allow the seismic design and assessment of new and existing buildings, respectively, by adopting linear spectral analysis. However, equivalent static forces are calculated as proportional to a reduced value of the spectral acceleration. The adopted reduction factor is named behavior factor and implicitly accounts for the capab...
Existing reinforced concrete buildings subjected to medium intensity earthquake loads often exhibit significant damage to structural and non-structural components that may compromise the structural safety and the building repairability. This damage is commonly concentrated on infills and partitions leading to relevant economic losses. This makes th...
Existing reinforced concrete buildings in the Mediterranean area are very vulnerable to seismic actions due to lack of proper seismic detailing and poor quality of concrete. Furthermore, they are likely to exhibit significant earthquake damage to non-structural components such as infills and partitions. Reconstruction processes followed to recent s...
Worldwide, substandard Reinforced Concrete (RC) buildings with unreinforced beam-column joints are widespread also in seismic prone areas. This work presents the performed experimental campaign related to cyclic tests on exterior unreinforced joints. The main investigated parameters are: the joint aspect ratio, the design typology for the beam-colu...
Under seismic load, Reinforced Concrete (RC) members may exhibit a flexure-controlled ductile (F) failure; otherwise, they may exhibit a shear-controlled brittle (S) failure or a combined flexural-shear (FS) failure. The identification of the failure mode determines RC members’ expected (and modelled) strength and deformation capacity. Approaches f...
Eurocode 8 allows force-based seismic design and safety assessment of buildings as if they were indefinitely linearly elastic. However, to implicitly account for their inelastic deformation capacity, Eurocode 8 allows reduction of the design values of seismic forces through a structure-dependant behaviour factor. Recent studies
showed that this des...
During an earthquake, the progressive damage of structural and nonstructural components of a structure yields to the degradation of their stiffness, thus resulting in a progressive increase of the vibration period of the structure as a whole. Also, the damage amount on structural and nonstructural elements, also known as Damage State (DS), can be d...
Two models of the 10-story reinforced concrete building tested at E-Defense laboratory in 2015 are built: the F model, in which nonlinear behavior is distributed over the element length, and the H model, in which nonlinear behavior is lumped in plastic hinges with a moment-chord rotation response assigned based on empirical formulations proposed in...
In this paper, empirical equations are proposed to calculate the moment-chord rotation response envelope of ductile rectangular reinforced concrete columns with deformed bars. The proposed envelope accounts for cyclic strength degradation and is defined by four characteristic points: yielding, maximum, conventional ultimate, and collapse. Also, the...
Recent seismic events worldwide have demonstrated the high vulnerability of existing school buildings and the urgent need to have reliable tools for the rapid seismic performance assessment and damage and loss quantification. Indeed, the significant damage observed on structural and non-structural components may have a significant impact in terms o...
The aim of this study is the analysis of seismic fragility of residential masonry buildings, with particular emphasis to the evolution of seismic behaviour over the years. To this purpose, a detailed and comprehensive taxonomy has been established, considering a restricted selection of building's features, avoiding the ineffective fragmentation of...
In this study, seismic vulnerability of Italian masonry buildings is analyzed taking advantage of the post-earthquake damage data recently released by the Italian Department of Civil Protection through the online platform Da.D.O. (Dolce et al. 2019). The main purpose of the study is to describe the damage attitude of several building's typologies,...
During an earthquake, the progressive damage of structural and nonstructural components of a structure yields to the degradation of their stiffness, thus resulting in a progressive increase of the vibration period of the structure as a whole. Also, the damage amount on structural and nonstructural elements, also known as Damage State (DS), can be d...
In this paper, the results of the cyclic experimental tests performed on ductile rectangular reinforced concrete columns with deformed bars are processed to define characteristic points of the lateral base moment – chord rotation response envelope. Four
characteristic points are determined: yielding, maximum, conventional ultimate, and collapse. T...
Existing RC buildings are often vulnerable to seismic loading, thus requiring retrofitting strategies to mitigate such vulnerability. This is certainly true for existing RC buildings realized in Italy before ‘70s and often designed to sustain gravity loads only. Such (low-standard) RC buildings typically present failure typologies very different fr...
Beam-column joints in existing Reinforced Concrete (RC) buildings are usually characterized by the absence of transverse reinforcement. The observation of post-earthquake damage, as well as several numerical and experimental studies, have soundly demonstrated the possible impact of the response of unreinforced joints on the damage – up to collapse...
Infills in existing reinforced concrete buildings are often vulnerable to seismic actions perpendicular to their plane (OOP actions), especially if also in-plane (IP) damage is present. This study aims at experimentally testing under OOP loading masonry infills that suffer or not previous IP damage, in their as-built conditions and in the presence...
A unified procedure for assessing the effectiveness of modelling strategies for existing buildings is proposed. The procedure is applied to unreinforced masonry and cast-in-place and precast reinforced concrete real buildings struck by earthquakes. A cross-structural-typology Matching Index (MI) is proposed. It aims to synthetically compare numeric...
Field surveys showed that the fabrication of infill, with particular emphasis on the connection with the surrounding reinforced concrete (RC) frame, may have a significant influence on the global response, earthquake damage and on the actions transmitted to the surrounding RC members.
This study reports and discusses the outcomes of an experimental...
This study investigates the seismic response of archetype infilled reinforced concrete buildings representative of the existing Italian residential building stock by focusing on the modelling aspects of the existing infills, including their failure modes and interaction with the frame. The study compares the seismic response of the considered build...
The aim of this study is to describe the evolution of vulnerability over the years for masonry buildings characterized by a good quality layout and/or a regular texture. To this aim, data collected shortly afterwards the L'Aquila 2009 earthquake are considered, recently released by the Italian Department of Civil Protection (DPC) through the Da.D.O...
This study investigates the seismic response of reinforced concrete buildings designed according to Italian regulations and construction practices for three different post-WWII periods, up to the 1990s. Additional key investigated parameters are the number of stories and the site hazard. The main issues related to non-seismic and early seismic desi...
Recent seismic events worldwide demonstrated the high vulnerability of existing school buildings and the urgent need to have reliable tools for the rapid seismic performance assessment and damage and loss quantification. Indeed, the significant damage observed on structural and non-structural components may have a significant impact in terms of dir...
In existing Reinforced Concrete (RC) buildings, the out-of-plane (OOP) collapse of masonry infills can be a significant issue for resulting damage and life safety in case of earthquake. Quite recently, research works from the literature have studied possible strengthening strategies to reduce the vulnerability of the infill panels due to OOP loadin...
The response of unreinforced beam-column joints represents a key issue in seismic vulnerability and fragility assessment of existing Reinforced Concrete (RC) buildings. A great attention has been focused on the investigation of the experimental response of unreinforced joints and their possible strengthening strategies.
In this study, an experiment...
The purpose of this study is the analysis of vulnerability trends, with particular emphasis to the evolution of the seismic behaviour of masonry buildings over the years due to the improvements in construction practices and to the enhancement of building materials over the years, also related to the subsequent enactment of seismic prescriptions. To...
In this study, nonlinear time-history analyses are performed to assess the floor response spectra of bare and infilled reinforced concrete framed buildings with different number of stories and designed according to Eurocode provisions for different intensity levels of the seismic action. Infill walls are modeled by neglecting and by accounting for...
Currently, in the framework of performance-based earthquake engineering, the seismic assessment of buildings should be performed by considering the safety of non-structural components. This is necessary to protect human life safety from their collapse, as well as to limit the economic losses associated with their damage. Typically, the safety asses...
The expected lateral response of reinforced concrete (RC) elements strongly depends on their failure mode. Code-conforming RC members are supposed to exhibit a flexural (F) ductile failure , with complete exploitation of their post-peak displacement/deformation capacity. However , substandard RC elements, which are typical of existing structures, m...
The seismic assessment and retrofit of non-conforming Reinforced Concrete (RC) buildings still represent a challenge for researchers and practitioners worldwide due to several aspects. On one hand, low standards RC buildings typically present some failure typologies very different from newly designed buildings, and such failure modes should be prop...
In this study a dedicated framework for seismic losses estimation in Reinforced Concrete buildings is presented, taking advantage of a simplified analytical structural analysis, a dedicated drift-based fragility curves and a specific repair cost analysis. To this aim, the mechanically based “Pushover on Shear Type model” (POST)-method, already know...
In this study, the hysteretic response of ductile Reinforced Concrete (RC) columns with plain bars is analyzed by evaluating the degradation of unloading and reloading stiffness with imposed inelastic displacement and the “pinching” behaviour, based on experimental data. The dependence of the hysteretic parameters on selected potential predictors i...
The last National Risk Assessment NRA for Italy was developed at the end of 2018 by the Department of Civil Protection (DPC) in response to the specific requirement of the Sendai Framework for Disaster Risk Reduction 2015-2030 to periodically adjourn the assessment of disaster risk. The methodology adopted to perform seismic risk assessment and bui...
In this paper, empirical fragility curves for reinforced concrete buildings are derived, based on post-earthquake damage data collected in the aftermath of earthquakes occurred in Italy in the period 1976–2012. These data, made available through an online platform called Da.D.O., provide information on building position, building characteristics an...
Under seismic load, Reinforced Concrete (RC) members may exhibit a flexure-controlled ductile (F) failure; otherwise, they may exhibit a shear-controlled brittle (S) failure or a combined flexural-shear (FS) failure. The identification of the failure mode deter-mines RC members’ expected (and modelled) strength and deformation capacity. Approaches...
Worldwide, substandard Reinforced Concrete (RC) buildings with unreinforced beam-column joints are widespread also in seismic prone areas. In this work, the performed experimental campaign related to cyclic tests on exterior unreinforced joints is presented. The main investigated parameters are related to the joint aspect ratio, the design typology...
Municipality Emergency Plans (MEPs) represent an essential tool for Italian municipalities, since they contain all the indications and procedures to face any expected or unexpected hazard in their territory. In the present work, the MEP of Palma Campania municipality (Napoli province, Southern Italy) completed in April 2016, is reported. The experi...
This work aims estimating seismic losses in residential-reinforced concrete
buildings, highlighting the influence of infills and services. First, the mechanical-
based "POST”-method is used to perform simplified (nonlinear static)
structural analyses, in the "shear-type” building hypothesis. Then, drift-based
fragility curves and repair cost analys...
The out-of-plane (OOP) response of unreinforced masonry (URM) infill walls under seismic loading has been widely studied in very recent times with both experimental and numerical investigations. It is recognized that the damage of infills due to in-plane (IP) seismic actions has a significant influence on their OOP response, by reducing the OOP str...
The reliable estimation of seismic losses due to damage to buildings is paramount for the post-emergency management and the planning of recovery activities. For residential reinforced concrete (RC) infilled buildings, a significant role in the computation of seismic loss is played by non-structural components, above all infills, partitions and serv...
In this study, out-of-plane experimental tests are performed on masonry partitions in reinforced concrete frames. The out-of-plane strength of reference as-built specimens with and without arching action is assessed. Then, specimens strengthened with an FRCM or with an FRP are tested in absence of arching effect. The application of composite materi...
Formulations for the assessment of the out-of-plane strength capacity of unreinforced masonry (URM) infills have been proposed in the literature and introduced in building codes. However, these formulations often do not account for the presence of openings. In this note, based on experimental data, a code-oriented proposal is presented for the corr...
The lesson-learned after the recent earthquakes highlighted the key role played by infills and services in damage and losses estimation of Reinforced Concrete (RC) buildings. Thus, their influence in seismic performance and loss estimation of selected case-study RC buildings is herein thoroughly analyzed. The selection of the case studies aims to b...
Currently, reinforced concrete (RC) members are usually realized by using deformed steel bars for longitudinal and transverse reinforcement. However, in many parts of the world, at least up to '60s, plain bars were usually adopted. Many experimental and numerical studies showed how the use of plain bars influences the deformation capacity of RC mem...
RC buildings designed for gravity loads only or according to obsolete seismic codes are widespread worldwide also in seismic prone areas. Numerical and experimental studies highlighted that the presence of masonry infills in Reinforced Concrete (RC) frames leads to the increase in their lateral strength and stiffness. Nevertheless, post-earthquake...
The response of unreinforced beam-column joints represents a key issue in seismic vulnerability and fragility assessment of existing Reinforced Concrete (RC) buildings. Within this framework, a great attention is focused on the investigation of the experimental response of unreinforced joints strengthened with different technologies, based on tradi...
The invaluable role played by risk applications in defining emergency management policies in the aftermath of a seismic event or at prioritizing scheme for seismic interventions ensured its centrality within international projects abroad and within the technical literature. Nevertheless, currently a unified approach for the development and applicat...
Unreinforced masonry infills resist out-of-plane seismic actions first by means of a flexural strength mechanism. However, unreinforced masonry is characterized by a low tensile strength. Hence, if only a flexural strength mechanism occurs, a very low out-of-plane strength is expected. However, under certain conditions, arching action can occur: th...
The nonlinear assessment of new and existing structures within a performance-based framework is nowadays more and more pursued not only for research purposes but also in practice. Especially when dealing with the nonlinear dynamic assessment of existing buildings, the need for refined strength and deformation capacity models for structural members...
In this study, empirical vulnerability curves for Italian masonry buildings are derived taking advantage of the post-earthquake damage data recently released by the Italian Department of Civil Protection through the online platform Da.D.O. Thus, a comprehensive analysis of data for L'Aquila 2009 seismic event has performed in order to determine onl...
The development of analytical methodologies for seismic vulnerability assessment and damage prediction, used in the evaluation of seismic damage scenarios and risk assessment of building portfolios, is necessarily based on a reasonable compromise between accuracy and simplicity, because of the detail level-often very low-of the available input data...
A wrong version of table 11 was present in the manuscript. Its updated and corrected version, consistent with the curves of Fig. 9, is herein reported (Table 1).
Experiments have demonstrated the effectiveness of fiber-reinforced polymer (FRP) materials for the seismic strengthening of deficient reinforced concrete (RC) beam-column joints. However, only a few studies have focused on the seismic response of joint subassemblies that are designed to withstand moderate seismic actions where a strong column-weak...
A set of about 25,000 residential reinforced concrete (RC) buildings has been investigated in this study to define fragility curves. The sample originates from a wide database, reported in the online Da.D.O. (Database of Observed Damage) platform, related to about 320,000 buildings inspected in the aftermath of the nine most devastating earthquakes...
Incremental dynamic analyses are performed on 48 infilled reinforced concrete buildings different for infill typology, number of storeys and design peak ground acceleration (PGA). A modelling strategy accounting for infills' interacting in-plane (IP) and out-of-plane (OOP) responses is implemented. The seismic displacement demand on buildings may b...