scholarly journals Modelling the seismic response of a 2-storey URM benchmark case study: comparison among different equivalent frame models

2021 ◽  
Author(s):  
Carlo Filippo Manzini ◽  
Daria Ottonelli ◽  
Stefania Degli Abbati ◽  
Corrado Marano ◽  
Emilia Angela Cordasco
Keyword(s):  
Global Scale ◽  
Masonry Building ◽  
Research Activity ◽  
Capacity Curves ◽  
Numerical Predictions ◽  
Structural Details ◽  
Modelling Uncertainties ◽  
Equivalent Frame ◽  
Unreinforced Masonry Building ◽  
Comparison Of The Results

AbstractThe paper presents the comparison of the results of non-linear static analyses performed with different software based on the equivalent frame (EF) modelling approach on a simple two-story unreinforced masonry building with rigid diaphragms. This study is part of a wider research activity carried out in the framework of the Italian Network of Seismic Laboratories (ReLUIS) projects, funded by the Italian Department of Civil Protection. Different configurations have been considered varying the layout of the openings on the bearing walls and the structural details. The EF models have been defined adopting as much as possible common assumptions, in order to reduce the epistemic modelling uncertainties and to facilitate the interpretation of the differences in the results obtained by the software. The comparison involved different aspects: the global scale response, in terms of capacity curves, the predicted damage pattern as well as checks at the local scale, in terms of distribution of the generalized forces. Moreover, in order to assess the reliability of the obtained results, the numerical predictions have been compared to an analytical upper bound reference solution. Finally, the sensitivity of the numerical response to the criterion adopted for the EF idealization of masonry walls has been investigated.

scholarly journals A comparative study on a complex URM building: part II—issues on modelling and seismic analysis through continuum and discrete-macroelement models

2021 ◽  
Author(s):  
G. Castellazzi ◽  
B. Pantò ◽  
G. Occhipinti ◽  
D. A. Talledo ◽  
L. Berto ◽  
...  
Keyword(s):  
Seismic Analysis ◽  
Dynamic Properties ◽  
Limit State ◽  
Central Italy ◽  
Nonlinear Static Analysis ◽  
Structural Safety ◽  
Masonry Building ◽  
Maximum Acceleration ◽  
Capacity Curves ◽  
Comparison Of The Results

AbstractThe paper presents the comparison of the results obtained on a masonry building by nonlinear static analysis using different software operating in the field of continuum and discrete-macroelement modeling. The structure is inspired by an actual building, the "P. Capuzi" school in Visso (Macerata, Italy), seriously damaged following the seismic events that affected Central Italy from August 2016 to January 2017. The activity described is part of a wider research program carried out by various units involved in the ReLUIS 2017/2108—Masonry Structures project and having as its object the analysis of benchmark structures for the evaluation of the reliability of software packages. The comparison of analysis was carried out in relation to: global parameters (concerning the dynamic properties, capacity curves and, equivalent bilinear curves), synthetic parameters of structural safety (such as, for example, the maximum acceleration compatible with the life safety limit state) and the response in terms of simulated damage. The results allow for some insights on the use of continuum and discrete-macroelement modeling, with respect to the dispersion of the results and on the potential repercussions in the professional field. This response was also analyzed considering different approaches for the application of loads.

A comparative study on a complex URM building. Part II: issues on modelling and seismic analysis through continuum and discrete-macroelement models

2021 ◽  
Author(s):  
Giovanni Castellazzi ◽  
Bartolomeo Pantò ◽  
Giuseppe Occhipinti ◽  
Diego Alejandro Talledo ◽  
Luisa Berto ◽  
...  
Keyword(s):  
Seismic Analysis ◽  
Dynamic Properties ◽  
Limit State ◽  
Central Italy ◽  
Nonlinear Static Analysis ◽  
Structural Safety ◽  
Masonry Building ◽  
Maximum Acceleration ◽  
Capacity Curves ◽  
Comparison Of The Results

Abstract The paper presents the comparison of the results obtained on a masonry building by nonlinear static analysis using different software operating in the field of continuum and discrete-macroelement modeling. The structure is inspired by an actual building, the "P. Capuzi" school in Visso (Macerata, Italy), seriously damaged following the seismic events that affected Central Italy from August 2016 to January 2017. The activity described is part of a wider research program carried out by various units involved in the ReLUIS 2017/2108 - Masonry Structures project and having as its object the analysis of benchmark structures for the evaluation of the reliability of software packages. The comparison of analysis was carried out in relation to: global parameters (concerning the dynamic properties, capacity curves and equivalent bilinear curves), synthetic parameters of structural safety (such as, for example, the maximum acceleration compatible with the life safety limit state) and the response in terms of simulated damage. The results allow for some insights on the use of continuum and discrete-macroelement modeling, with respect to the dispersion of the results and on the potential repercussions in the professional field. This response was also analyzed considering different approaches for the application of loads. URM building.

scholarly journals Modelling the nonlinear static response of a 2-storey URM benchmark case study: comparison among different modelling strategies using two- and three-dimensional elements

2021 ◽  
Author(s):  
Francesco Cannizzaro ◽  
Giovanni Castellazzi ◽  
Nicola Grillanda ◽  
Bartolomeo Pantò ◽  
Massimo Petracca
Keyword(s):  
Three Dimensional ◽  
Seismic Load ◽  
Masonry Building ◽  
Capacity Curves ◽  
Collapse Mechanisms ◽  
Software Packages ◽  
Modelling Strategies ◽  
Nonlinear Static ◽  
Unreinforced Masonry Building ◽  
Benchmark Structures

AbstractThis paper aims at comparing the use of different software environments for the study of a simple unreinforced masonry building through nonlinear static analyses. The presented results are part of a wider research project conducted within the ReLUIS consortium, and specifically within a research task whose purpose is providing practitioners with results and tools for an aware employment of commercial software packages for modelling masonry structures. In this study one of the benchmark structures of the research program is analysed; a two-story building characterized by rigid horizontal diaphragms, considering different configurations in terms of openings arrangements and effectiveness of ring beams, is subjected to seismic load conditions. Software packages considering two- and three- dimensional structural models are employed, and the obtained results are compared in terms of capacity curves and collapse mechanisms. One of the critical aspects on the basic assumptions made by software in terms of way to apply the horizontal loads is further investigated. In addition, the role of the shear strength is analysed correlating the mechanical properties to be adopted with micro- and macro- models. The considered models present very different features, and the analogies and differences obtained in the results are critically interpreted in view of the different hypotheses made by the software tools in terms of modelling strategies and adopted constitutive laws.

scholarly journals On the reliability of the equivalent frame models: the case study of the permanently monitored Pizzoli’s town hall

2021 ◽  
Author(s):  
Stefania Degli Abbati ◽  
Paolo Morandi ◽  
Serena Cattari ◽  
Enrico Spacone
Keyword(s):  
Central Italy ◽  
Ambient Vibration ◽  
Second Phase ◽  
Masonry Building ◽  
Town Hall ◽  
Central Italy Earthquake ◽  
Ambient Vibration Tests ◽  
Equivalent Frame ◽  
Comparison Of The Results

AbstractThis paper presents the comparison of the results of modal and nonlinear analyses carried out on a 2-story masonry building with rigid diaphragms, inspired by the Pizzoli’s town hall (AQ, Italy). The case study is one of the Benchmark Structures (labeled BS6) in the “URM nonlinear modelling–Benchmark project” funded by the Italian Department of Civil Protection (DPC) within the framework of the ReLUIS projects. The building has been instrumented since 2009 with a permanent monitoring system by the Osservatorio Sismico delle Strutture (OSS) of the DPC and was hit by the 2016/2017 Central Italy earthquake sequence. In the research first phase, modal and nonlinear static analyses were carried out in a blind prediction, without any preliminary calibration of the models, but referring only to commonly made assumptions on materials and modelling. Five computer programs based on the Equivalent Frame Model (EFM) approach were used. Four different structural configurations were considered: with weak spandrels (A), with tie rods coupled to spandrels (B), with RC ring beams coupled to spandrels (C) and with “shear type” idealization (D). In the research second phase, two of the developed EFMs were calibrated in the elastic range using the results of available Ambient Vibration Tests (AVTs). The models were then validated in the nonlinear range by simulating the dynamic response of the structure recorded during the mainshocks of the 2016/2017 Central Italy earthquake. Recorded and numerical results were compared at both the global and local scale.

Seismic Enhancement of Masonry Buildings Strengthened through GFRP Reinforced Mortar Coating

2015 ◽  
Vol 796 ◽  
pp. 53-67 ◽  
Author(s):  
Natalino Gattesco ◽  
Ingrid Boem
Keyword(s):  
Seismic Vulnerability ◽  
Mechanical Response ◽  
Numerical Study ◽  
Experimental Tests ◽  
Masonry Wall ◽  
Masonry Building ◽  
Masonry Buildings ◽  
Capacity Curves ◽  
Displacement Capacity ◽  
Equivalent Frame

The reduction of seismic vulnerability of existing masonry buildings through the application on the walls of a mortar coating reinforced with a GFRP (glass fiber reinforced polymer) mesh is studied and discussed. Numerous experimental tests, carried out by the authors, demonstrate the effectiveness of this technique for enhancing the mechanical response of the walls, both subjected to in-plane and out-of-plane actions. In the study, the capacity curves of an existing unreinforced masonry building are compared with those of the same building strengthened with the GFRP reinforced mortar coating technique. An almost regular two storey building is considered in the numerical study and it is analyzed by adopting the method of the equivalent frame. Two different types of masonry are considered in the study: solid bricks and rubble stones. Static nonlinear analyses are carried out and the nonlinearity of the material of the wall elements (piers and spandrels) is considered through the introduction of plastic hinges in the plane of the masonry wall. The results evidence a significant increase in terms of shear resistance, displacement capacity and total strain energy. The collapse due to bending of piers in most cases of strengthened buildings occurred before than the ultimate shear drift was obtained.

Mechanical Analysis for the Assessment of the Seismic Capacity of Masonry Buildings’ Classes in the City Centre of Sulmona (Italy)

2010 ◽  
Vol 133-134 ◽  
pp. 623-628
Author(s):  
Marco Munari ◽  
Gianluca Busolo ◽  
Maria Rosa Valluzzi
Keyword(s):  
Mechanical Analysis ◽  
City Centre ◽  
Masonry Buildings ◽  
Seismic Capacity ◽  
Limit States ◽  
Damage Level ◽  
Capacity Curves ◽  
Perfectly Plastic ◽  
Displacement Capacity ◽  
Comparison Of The Results

A mechanical based method for the evaluation of the seismic capacity of masonry buildings’ classes in terms of damage limit states is presented: the purpose of the study is to achieve, in the framework of vulnerability analyses at territorial scale, reliable values for the damage level of vulnerability classes of masonry buildings, depending on the seismic input level. This approach is, in fact, designed as a “1st level” tool based on easily traceable information provided by expeditious surveys. Once identified a limited number of typological, physical and mechanical parameters that are necessary to define each vulnerability class, a significant number of simplified models of masonry buildings belonging to each class has been created. Non-linear static analysis of these models allowed the creation of bilinear elastic perfectly plastic capacity curves: the displacement capacity described by these curves is related with the actual displacement values required by seismic intensities associated to different return periods. It is so possible to identify, for different vulnerability classes and different seismic inputs, the loss of capacity in terms of damage level of each building. An application of the method to models representative of masonry buildings in the historical centre of Sulmona, in L’Aquila province, and a comparison of the results with others obtained with other methodologies of assessment are presented.

Humidity-Induced Cohesion Effects in Granular Media

2000 ◽  
Vol 627 ◽  
Author(s):  
Nathalie Fraysse ◽  
Luc Petit
Keyword(s):  
Granular Medium ◽  
Granular Media ◽  
Global Scale ◽  
Interparticle Forces ◽  
Wetting Properties ◽  
Small Glass ◽  
Capillary Bridges ◽  
Scale Properties ◽  
Comparison Of The Results ◽  
Maximal Stability

ABSTRACTExperiments were performed under accurately-controlled humidity conditions in order to quantify effects induced by humidity on granular materials. Measurements of the maximal stability angle of a pile made of small glass beads are reported as a function of the relative vapor pressure in the cell, up to close to saturation. The comparison of the results obtained with fluids differing in their molecular interactions with glass, namely water and heptane, shows that the wetting properties of the interstitial liquid on the grains have a strong influence on the cohesion of the non-saturated granular medium. This suggests that gravimetric experiments which could indirectly give information on the size of the capillary bridges that form between grains should be useful to understand the close connection that exists, through interparticle forces, between microscopic properties such as wetting properties and surface roughness of the grains, and global-scale properties of the pile, as its stability and flowability.

Parapets, Politics, and Making a Difference: Lessons from Christchurch

2017 ◽  
Vol 33 (4) ◽  
pp. 1241-1255
Author(s):  
Ann Brower
Keyword(s):  
New Zealand ◽  
Bright Light ◽  
Unreinforced Masonry ◽  
Masonry Building ◽  
Dalai Lama ◽  
Main Street ◽  
Making A Difference ◽  
Remediation Time ◽  
Unreinforced Masonry Building

At 12:51 on 22 February 2011, 12 people died beside me. The parapet and facade of an unreinforced masonry building on the main street of Christchurch, New Zealand, crushed the bus that I was riding. I'm the only one left, the lucky 13th. My leg, my hand, and my soul will never be the same. I broke more bones than the surgeons were willing to count, spent two months in the hospital, and most of a year off work. I walked, slept, and dreamed in a fog for four years. It cost half a million dollars to save my left leg. I treasure that leg, scars and all, but still feel the earthquake in every step. In this opinion paper, I share my story—from the earthquake, to the Bright Light, to the Dark Place, to the hospital, to the Dalai Lama, to the halls of Parliament. I also share the story of a nation coming to grips with its home on the Ring of Fire. The story ends on 8 May 2016, when Parliament passed the new Building Act, complete with a ministerially titled “Brower Amendment” that halved the remediation time for unreinforced masonry parapets and other falling hazards. I conclude with the lessons I've learned on making a difference.

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