Alberto Pavese

University of Pavia | UNIPV · Department of Civil Engineering and Architecture

This research work is related to the evaluations of some modelling assumptions of the stick–slip phase of the Friction Pendulum TM System (FPS) on the seismic response of base-isolated buildings. Although several theoretical and experimental research findings show the complexity of the FPS nonlinear behaviour, the current international seismic desi...

Experimental and analytical studies on Concave Sliding Surface devices have underlined that the hysteretic characteristics under bi-directional input motion are highly non-linear, in comparison with the uni-directional case. The force response of the device along both directions of motion strongly depend on the shape of the trajectory, because of t...

Anchorage system FRP Fiber reinforced cementitious matrix (FRCM) Reinforced concrete Spike anchors Textile reinforced mortar (TRM) a b s t r a c t This paper investigates the effectiveness of carbon fiber spike anchors as a means of anchoring externally bonded (EB) fiber-reinforced polymers (FRP) and textile reinforced mortar (TRM) sheets into conc...

The feasibility and efficiency of a seismic retrofit intervention using externally bonded fiber-reinforced polymer composites on existing reinforced concrete frame systems, designed prior to the introduction of modern standard seismic design code provisions in the mid-1970s, are herein presented, based on analytical and experimental investigations...

The research work presented in this paper deals with the seismic assessment of hol-low bridge piers strengthened with fibre-reinforced polymer (FRP). The scope of the strengthening is to overcome some common deficiencies derived from the use of non-seismic design rules, which can often lead to inadequate response when operating in cyclic loading. T...

Quantitative seismic loss assessment has become an increasingly popular tool for evaluating the seismic performance of structures. The growth in popularity is largely in response to a desire to look beyond the traditional life safety performance objective and instead consider also economic losses and downtime due to earthquakes. A key step in the l...

This paper presents a series of shaking table tests on a full-scale flat-bottom steel silo filled with soft wheat, under isolated-base conditions. The tested specimen is a 3.64 m-diameter 5.50 m-height corrugated-wall cylindrical silo, representing the smallest manufactured silo available in the catalogue of an Italian commercial silo provider. Cur...

The safety of existing bridges represents a serious problem in Italy since these structures are fundamental for the national transportation system and, at the same time, can be subject to significant deterioration phenomena linked to the fact that the construction period typically dates back to the 1960s. This study involves the seismic analysis of...

Bridge structural systems are often represented by high risk levels, from several standpoints. The strategic role they generally play in the infrastructure network leads to significant exposure characteristics, with a resulting high risk level. Even though the seismic action is not always a key issue for a considered bridge, excessive horizontal lo...

In recent earthquakes, besides the sloshing of the content and the failure of piping systems, among the most common damages suffered by traditional fixed-base steel tanks, there is the uplift, in worse cases the overturning, and the “elephant-foot-buckling” of perimeter walls. Over possible solutions, base-isolation of tanks through sliding isolato...

The Italian road network comprises many bridges that were constructed around the middle of last century and are now close to, or have exceeded, their intended design lives. The advanced state of degradation of many of the bridges has been a contributing factor in a number of collapses in recent years, with the problem being particularly prevalent i...

In this research work the outcomes of a hybrid experimental campaign are analyzed, in order to evaluate the influence of aftershock events on the frictional response of sliding-based isolation devices for buildings. To achieve this, a hybrid testing framework was accordingly defined, by considering a numerical substructure, in terms of a simplified...

The seismic risk assessment of industrial facilities mainly relies on historical data and the analysis and design of uncoupled secondary components. Accordingly, the dynamic interaction between primary structures and process equipment is overlooked. The SPIF project – Seismic Performance of Multi‐Component Systems in Special Risk Industrial Facilit...

The seismic performance of existing RC frame buildings seismically retro-fitted by base isolation is examined. Two different types of isolation systems are considered, i.e.: rubber-based and friction-based isolation systems, respectively. Two different performance levels are examined, namely: Global collapse prevention and Usability preventing dama...

This paper reports on a series of shaking table tests on a full-scale flat-bottom steel silo filled with soft wheat, characterized by aspect ratio of around 0.9. The specimen was a 3.64-m diameter and 5.50-m high corrugated-wall cylindrical silo. Multiple sensors were used to monitor the static and dynamic response of the filled silo system, includ...

Past earthquakes demonstrated the high vulnerability of industrial facilities equipped with complex process technologies leading to serious damage of the process equipment and multiple and simultaneous release of hazardous substances in industrial facilities. Nevertheless, the design of industrial plants is inadequately described in recent codes an...

Recent destructive earthquakes in China (Sichuan, 2008 and Yushu, 2010), Japan (Tohoku, 2011) and Italy (Emilia, 2012) highlighted the social and the political consequences of seismic risk due especially to industrial facilities. More precisely, critical interactions between the supporting structure and process components reveal to be extremely vul...

Curved Surface Slider (CSS) devices have been widely used in recent years for the reduction of seismic vulnerability of structural systems. Recent risk assessment studies have revealed that base isolated systems can be characterized by higher seismic risk with respect to their fixed-base counterparts. It is believed that this unexpected outcome is,...

Curved Surface Slider devices have been widely used in last years for the protection of both building and structural systems. The spherical shape of the implemented sliding surfaces provide a certain recentering capability, which is generally combined to significant amount of energy dissipation, due to the frictional characteristics of the adopted...

Base isolation represents one of the most efficient strategy for the reduction of the structural vulnerability of buildings and bridges. Design procedures generally aim to provide the proper period shift, in order to reduce spectral acceleration values and, consequently, the base shear and internal forces. On the other hand, high displacement deman...

The ASA (Advanced Seismic Assessment) module is a post-earthquake technical intervention service, developed over the years by the EUCENTRE Foundation through a series of national and European pilot projects, field exercises, and direct experience, after the latest major seismic events that struck Italy since 2009. The system consists of a service m...

Double Curved Concave Surface Sliders (DCCSS) are seismic isolators based on the pendulum principle widely used worldwide. Coherently with European code, DCCSS do not include any mechanical elements as end-stopper. In case of displacement higher than those associated with the design earthquakes, the inner slider runs on the edge of the sliding surf...

The hybrid simulation method is used to test one or some components of a prototype structure subjected to a plausible loading history, accounting for their interaction with the untested ones, which are simulated numerically. If tested components have similar numerical counterparts, a possible approach to reduce simulation errors is to update the pa...

Curved Surface Slider (CSS) devices have been widely used in recent years for the reduction of seismic vulnerability of structural systems. The most important aspects to be considered in the design phases, such as the dependence of frictional properties on parameters such as vertical load, contact pressure, temperature rise and repetition of cycles...

In the recent past, numerical and experimental investigations on full-scale isolators have led to extensive improvements in seismic isolation techniques for bridge structures. Significant advances in dynamic testing techniques have been made at both software and hardware levels, and the response of an isolated bridge can be realistically simulated....

Base-isolated structural systems have been more and more investigated through both numerical and experimental campaigns, in order to evaluate their effective advantages, in terms of vulnerability reduction. Thanks to the lateral response of proper isolation devices, large displacement demands can be accommodated, and the overall energy of the seism...

Sliding bearings have been extensively used to implement base isolation design in civil engineering works. Testing of isolators is conducted for characterizing the design properties to be used in structural analysis, as well as for verifying the performance of the devices before their application. The quantification of the effects of scaling specim...

The collapse of the Polcevera bridge in Italy represents a serious event which seems to be a direct result of cumulated local damages due to the aggressive environment of the construction site. Recently, evidence of corrosion of both ordinary and post-tension steel reinforcements were detected, in addition to concrete carbonation. Such phenomena ge...

In last years procedures for structural health monitoring have been more and more improved, thanks to growing innovation in sensor technology and in knowledge of damage detection strategies. Nonetheless, in the recent past some collapse events of important bridge structures have occurred, and significant social and economical losses have been exper...

Modeling strategies of base isolation devices allow extremely realistic simulation of the structural response of seismically isolated systems. Especially whenever Non-Linear Time History Analyses are performed, actual hysteretic constitutive laws can be implemented in the most common commercial software and the proper behavior of all the installed...

VIDEO PRESENTATION ABSTRACT: Concave Surface Slider devices have been more and more investigated in last years, and several issues have been pointed out by several experimental campaigns. Frictional properties at sliding interfaces can be considered as functions of some important response parameters, such as sliding velocity, contact pressure, temp...

Concave Surface Slider devices have been more and more investigated in last years, and several issues have been pointed out by several experimental campaigns. Frictional properties at sliding interfaces can be considered as functions of some important response parameters, such as sliding velocity, contact pressure, temperature rise and dissipated e...

Hybrid simulation reproduces the experimental response of large‐ or even full‐scale structures subjected to a realistic excitation with reduced costs compared with shake table testing. A real‐time control system emulates the interaction between numerical substructures, which replace subparts having well‐established computational models, and physica...

Structural vulnerability of buildings can be significantly reduced if seismic isolation systems are implemented at the base of the overall system. Thanks to the low stiffness characteristics, reduced forces are experienced during a seismic event, whereas displacements are limited by the provided energy dissipation of the installed devices. In the d...

Non-linear time history analysis represents the most realistic simulation of the effects of selected seismic events on a structural system. Especially when natural recorded signals are applied, it is possible to evaluate maximum values of internal forces for all elements, as well as if the studied structure had been subjected to the considered eart...

This paper describes a preliminary experimental study aimed at investigating the force-displacement behavior of Variable Friction base isolation Systems (VFSs). Full-scale VFS prototypes were tested under cyclic loading conditions. A series of dynamic hybrid tests simulating the response of a full-scale single-story structure isolated with VFS devi...

p>Seismic isolation techniques for bridge structures have been more and more improved in last years, thanks to results of both numerical and experimental investigations on full-scale devices. In addition, significant advances on testing techniques have led to extremely realistic responses of an isolated bridge. Particularly, hybrid tests allow to c...

Extensive damage to school buildings has been observed during past earthquakes in Italy, with the 2002 Molise earthquake resulting in the complete collapse of a school building, leading to numerous casualties. In this paper, data provided by instruments installed in a number of school buildings throughout Italy from both ambient vibration and trigg...

In the present work the experimental response of the Curved Surface Slider (CSS) is investigated through an experimental campaign, carried out on a full-scale prototype subjected to both unidirectional and bidirectional tests. The aim of the study is to assess the effect of vertical load, speed and sustained motion on the frictional response of the...

Experimental research on the lateral response of Concave Surface Sliders (CSS) under bi-directional earthquake excitations has shown significant differences in comparison to the uni-directional case. This is mainly due to the stepwise variation of the direction of the frictional force, which is assumed to be parallel to the device trajectory; on th...

p>Nowadays base isolation represents one of the most effective solutions for seismic protection of both building and bridge structures. Thanks to the provided low stiffness and the high dissipation capacity, a significant reduction of internal forces induced in the superstructure can be obtained, with limited increased displacement demands. However...

Research activity on Concave Surface Slider devices has grown exponentially in last decades. Frictional response leads to high values of dissipated energy during a seismic event, so that a significant reduction of both displacement and force demands can be experienced by the base-isolated structural system. On the other hand, several issues have be...

Hybrid Testing is becoming very popular within the most advanced testing techniques; the use of sub-structuring further enhance the appeal of such testing method, allowing cost effective full scale tests. Full scale specimens, in fact, generally require large testing installations, high force and displacement capacity. On the other hand, full or la...

During the first minutes after the occurrence of a catastrophic event, the difficulties that the Mayor may meet in emergency management are several. “The Mayor is the municipal civil protection authorities. When an emergency occurs in the municipality, the Mayor takes over the management of the emergency services who insist on the territory of the...

Background In the field of seismic analysis of structures, the use of appropriate Finite Elements software packages to manage more complex numerical models and to run more sophisticated analyses (such as nonlinear dynamic time-history analyses) in very short runtimes has increased significantly in the last decades. In order to have confidence in th...

This paper presents a summary of the experimental dynamic response of curved surface sliders as resulting from more than 1000 dynamic tests on about 60 different types of devices performed at the laboratory of the EUCENTRE Foundation. Two different kinds of low-friction sliding materials have been employed in the devices, derived from polyamide (PA...

Aim of this work is to characterize the frictional properties of different sliding materials employed in isolation devices, such as Curved Surface Sliders (CSS). This study is based on the results of a large experimental campaign of tests conducted on more than 70 different types of CSS, performed over several years at the experimental facility of...

The present study has been carried out within the framework of the research project PRISMA (PiattafoRme cloud Interoperabili per SMArt-government), with the purpose of studying the response of existing constructions designed for gravity loads only in the Sicily Region (Italy). A two storey reinforced concrete building, located nearby Messina city h...

A general seismic event can be considered as the superposition of two individual time histories of ground acceleration, acting simultaneously at the base of a structural system, along the main directions of a given reference system. Response spectra can be computed either for each component, or for the global seismic event, by considering a Single...

Extensive damage to school buildings has been observed during past earthquakes in Italy, with the 2002 Molise event resulting in the complete collapse of a school building leading to numerous casualties. As part of a wider project in Italy to assess the seismic risk in school structures, six school buildings of various construction typologies were...

Experimental studies performed on friction-based isolators have shown widely sparse frictional response, as direct effect of intrinsic properties of the devices and the vertical load variation. Moreover, in practical applications mounting laying defects consisting of uneven inclinations of the sliding surfaces with respect to the horizontal plane h...

Concave surface slider (CSS) devices represent an effective solution for base-isolation design problems. In such isolators the energy dissipation capability is induced by the sliding motions which occur at one or more sliding interfaces. The spherical shape of the sliding surfaces provides a significant recentering behavior, by means of the stepwis...

In the last decades, particular attention has been paid to the seismic vulnerability of existing reinforced concrete buildings designed for gravity loads only. Such buildings, designed before the introduction of capacity design in modern seismic codes, are very common, particularly in seismic prone countries of the Mediterranean area. Due to poor d...

The frictional response of Concave Surface Slider (CSS) devices has been more and more investigated both experimentally and numerically. These isolators have shown many advantages in comparison to the commonly used typologies of devices, such as lead rubber bearings or low and high damping rubber bearings: when implemented in structural systems, th...

The experimental behaviour of Concave Surface Slider devices has been deeply investigated in the recent past. Several static and dynamic tests have shown non-negligible dependencies of the friction coefficient on important response parameters, such as sliding velocity and contact pressure at the sliding interfaces. Moreover, an additional decay tre...

Base isolation represents one of the most effective solution for passive protection of structural systems against earthquakes. The main principle of such a technique is related to the reduction of internal forces and deformation of a given structure, by means of an isolation level, able to dissipate significant amounts of energy and to accommodate...

Sommario Il modulo ASA (Advanced Seismic Assessment) è un servizio di intervento tecnico nel post terremoto, che la Fondazione EUCENTRE ha sviluppato negli anni attraverso una serie di progetti pilota nazionali ed europei, di esercitazioni su campo e di esperienze dirette in seguito agli ultimi tre grandi eventi sismici che hanno colpito l'Italia d...

The research described in this paper investigates the seismic behaviour of lightly reinforced concrete (RC) bearing sandwich panels, heavily conditioned by shear deformation. A numerical model has been prepared, within an open source finite element (FE) platform, to simulate the experimental response of this emerging structural system, whose squat-...

Concave Surface Slider (CSS) devices represent an effective solution for base-isolation design problems. In such isolators the energy dissipation capability is induced by the sliding motions which occur at one or more sliding interfaces. The spherical shape of the sliding surfaces provides a significant recentering behavior, by means of the stepwis...

Nowadays research in earthquake engineering is mainly experimental and in large-scale; advanced computations are integrated with large-scale experiments, to complement them and extend their scope, even by coupling two different but simultaneous tests. Earthquake engineering cannot give answers by testing and qualifying few, small typical components...

The influence of the seismic performance of existing bridges on the functionality of communication infrastructures is widely recognized as a crucial issue. Therefore, Hybrid Simulation with Dynamic Substructuring (HS-DS) was selected for assessing the seismic response of a two-pier reinforced concrete (RC) bridge at the Eucentre TREES Laboratory of...

Assessment if bi-directional response of an isolated system

In the present work, a tridimensional model of double concave surface slider with non-articulated slider has been studied, in order to model the response of the isolator subjected to a generic earthquake motion. The geometric model simulates the possible construction laying defects in terms of inclination of both the sliding surfaces with respect t...

In this paper a simplified assessment procedure for multi-span, reinforced concrete (R.C.) bridges will be described and a numerical example will be presented. The proposed procedure is similar to the V.C. Method developed by Dolce et al. (2005) for reinforced concrete frames, conveniently modified in order to be applied to this different kind of s...

A wide test campaign has been carried out at the EUCENTRE TREES Lab of Pavia (Italy), on almost 400 Curved Surface Sliders (CSS) of two different typologies, designed to feature the same structural response from the performance point of view. Test campaigns of comparable size are not currently documented or public, to the authors' knowledge. Result...

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