scholarly journals Effects of Dissipative Systems on the Seismic Behavior of Irregular Buildings—Two Case Studies

Buildings ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 202
Author(s):  
Marco Miani ◽  
Caterina Di Marco ◽  
Giada Frappa ◽  
Margherita Pauletta
Keyword(s):  
Technical Information ◽  
Structural Response ◽  
Torsional Stiffness ◽  
Dissipative Systems ◽  
Seismic Action ◽  
Existing Building ◽  
Heritage Buildings ◽  
Fluid Dampers ◽  
The 1960S ◽  
Energy Dissipation Devices

Conservation of heritage buildings has become a very important issue in many countries, as it is in Italy, where a great number of existing buildings of historical–artistic importance are seismically vulnerable. To improve existing building behavior, researchers focus on the design of retrofit interventions. This paper presents the application of energy dissipation devices in the retrofit of two existing Reinforced Concrete (RC) buildings, both irregular in plan and along their heights, designed for gravitational loads only. These buildings are representative of Italian public housing built in the 1960s and early 1970s. Technical information and mechanical properties of materials are presented, and non-linear analyses are carried out to evaluate the buildings’ behavior under earthquake loads. Many of their structural members do not satisfy the verifications required by the Italian Building Code. Retrofit interventions with buckling-restrained axial dampers in one building and viscous fluid dampers in the other are proposed. The verifications of the retrofitted buildings and the amount of the energy absorbed by the devices with respect to that absorbed by the unretrofitted buildings show the effectiveness of the proposed interventions. Moreover, it is demonstrated that adequate dispositions of the dissipative devices in plan and along the height increase the torsional stiffness of the buildings, improving their structural response under seismic action.

scholarly journals Seismic response of stone masonry building with wooden band

2020 ◽  
Vol 16 (6) ◽  
pp. 513-522
Author(s):  
Govinda Khatri ◽  
Govind Prasad Lamichhane
Keyword(s):  
Seismic Vulnerability ◽  
Structural Response ◽  
Masonry Wall ◽  
Stone Masonry ◽  
Masonry Building ◽  
Structural Members ◽  
Strong Earthquakes ◽  
Existing Building ◽  
Heritage Buildings ◽  
Strengthening Technique

Most stone-masonry structures were built at a time when seismic risk was not considered in their design. Recent moderate to strong earthquakes have confirmed the vulnerability of heritage buildings, especially those constructed with unreinforced-masonry materials in various developing countries, worldwide. Proper assessment of the seismic performance and of the potential deficiency of existing heritage structures forms the basis for determining the degree of intervention needed to preserve their heritage values. Analysis of masonry wall confined by wooden band has been carried out using various structural analysis programs. In analysis appropriately considered and introduced link element such as hook, gap and spring at connecting nodes of vertical and horizontal timber elements. The result shows that the traditional floors and spandrels of the existing structure are the vulnerable parts which need strengthening of them to assure the structural members are able to resist seismic vulnerability. The required improvement and strengthening technique in existing building are proposed and better results are marked. The analysis of the modified structure shows considerably improvement in the dynamic characteristics of the buildings and overall structural response of those.

scholarly journals Hygric Properties of Machine-Made, Historic Clay Bricks from North-Eastern Poland (Former East Prussia): Characterization and Specification for Replacement Materials

Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6706
Author(s):  
Maria Tunkiewicz ◽  
Joanna Misiewicz ◽  
Pawel Sikora ◽  
Sang-Yeop Chung
Keyword(s):  
Historic Buildings ◽  
Micro Computed Tomography ◽  
Existing Building ◽  
Clay Bricks ◽  
North Eastern ◽  
Heritage Buildings ◽  
Experimental Laboratory ◽  
Materials Used ◽  
East Prussia

This paper deals with the hygric characterization of early 20th century machine-made clay bricks, representative of great number of historical buildings in north-eastern Poland. Heritage buildings have a high potential for adaptive reuse, which is strictly connected with an urge for knowledge about the properties of these existing building envelopes. To better understand the hygric behavior of historic buildings, various experimental laboratory tests, including density, water absorption, compressive strength and freeze-thaw resistance, were conducted. In order to assess the microstructural characteristics of the tested bricks, mercury intrusion porosimetry (MIP) and X-ray micro-computed tomography (micro-CT) tests were performed. These tests were conducted on clay bricks from historic buildings, as well as on those that are currently being produced, in order to identify the relationship between the materials used in the past and the replacements produced presently. This paper addresses the lack of systematic application of existing standards for evaluating the state of the conservation of historic bricks and for establishing the specifications for replacement bricks. The results of conducted study and further research will be the basis for creating a historic materials database. It would be a useful tool for selecting bricks that correspond with the historically used materials and help to maintain homogenous structure of the restored buildings.

Use of hygrothermal modeling to validate the application of an open-cell spray-foam insulation application to a high-rise heritage building in Winnipeg, Manitoba

2019 ◽  
Vol 46 (11) ◽  
pp. 1021-1031 ◽  
Author(s):  
John A. Wells ◽  
Robert Spewak
Keyword(s):  
Sensor Data ◽  
Analysis Tool ◽  
Building Stock ◽  
Accurate Analysis ◽  
Open Cell ◽  
Existing Building ◽  
Moisture Sensor ◽  
Heritage Buildings ◽  
Interior Face

The increasing cost of new building construction has made repurposing existing building stock economically more viable compared with a green site new build. In addition to capital cost benefits, increasing urban densification through repurposing existing buildings is one of the solutions for enhancing the urban environment. This paper summarizes the investigative work completed to substantially improve the energy efficiency of a heritage 10 storey building in Winnipeg, Manitoba. The investigative work for the remediation involved hygrothermal modeling to rationalize the introduction of thermal insulation to the interior face of the exterior walls. Based on the modelling, an open-cell spray foam was applied to the interior face of the masonry walls. Temperature, moisture, and relative humidity sensors were placed in various locations throughout the building to monitor the exterior walls, primarily to identify if deleterious levels of moisture were accumulating in the masonry. The results were also used to compare the in-situ performance of the building with the predicted performance from the hygrothermal models. The investigation confirmed that obtaining accurate in-situ moisture readings in masonry products is significantly impacted by initial internal moisture levels, necessitating pre-test calibration. Regardless, moisture sensor data accumulated to date indicate that after six years of monitoring, deleterious levels of moisture in the masonry and plaster are not occurring in the exterior walls, which is in good agreement with hygrothermal model results for open-cell foam. The results of this investigation confirm that the implementation of hygrothermal modeling is an effective and accurate analysis tool in the long-term durability assessment of building envelopes for heritage buildings.

Strong-Motion Data from Structural Response Recorders in Indian Earthquakes

2012 ◽  
Vol 28 (1) ◽  
pp. 77-103 ◽  
Author(s):  
Sudhir K. Jain ◽  
A. D. Roshan ◽  
Siddharth Yadav ◽  
Sonam Srivastava ◽  
Prabir C. Basu
Keyword(s):  
Peak Ground Acceleration ◽  
Structural Response ◽  
Time History ◽  
Strong Motion ◽  
Ground Acceleration ◽  
Motion Data ◽  
The Past ◽  
Simple Instrument ◽  
Low Costs ◽  
The 1960S

In the 1960s several hundred structural response recorders (SRR) were installed all over India. An SRR is a simple instrument consisting of six seismoscopes that provide “maximum response” during an earthquake, without providing the time history. In the past earthquakes, these SRRs have provided several hundred records but they have not been effectively utilized for hazard studies because the measurements from these instruments are considered crude. This paper compares the data obtained from SRRs with that from more modern strong-motion accelerographs (SMAs) for four earthquakes in India. It is shown through statistical analysis that the response obtained from the SRRs is comparable to that from the SMAs. A method has been presented for estimating peak ground acceleration (PGA) from SRR data. Thus, it is shown that SRRs can provide a substantial amount of PGA data for attenuation studies. Many countries may find SRRs useful because of the low costs associated with their manufacture and maintenance.

scholarly journals Vibration Control Devices for Building Structures and Installation Approach: A Review

2019 ◽  
Vol 29 (2) ◽  
pp. 74-100 ◽  
Author(s):  
Waseem Sarwar ◽  
Rehan Sarwar
Keyword(s):  
Energy Dissipation ◽  
Vibration Control ◽  
Passive Control ◽  
Search Algorithm ◽  
Structural Response ◽  
Building Structures ◽  
Analysis And Design ◽  
Control Devices ◽  
Energy Dissipation Devices ◽  
Energy Absorbing

Abstract Retrofit and structural design with vibration control devices have been proven repeatedly to be feasible seismic hazard mitigation approach. To control the structural response; supplemental energy dissipation devices have been most commonly used for energy absorption. The passive control system has been successfully incorporated in mid to high rise buildings as an appropriate energy absorbing system to suppress seismic and wind-induced excitation. The considerable theses that are highlighted include vibration control devices, the dynamic behavior of devices; energy dissipation mechanism, devices installation approach and building guidelines for structural analysis and design employing vibration control devices also, design concern that is specific to building with vibration control devices. The following four types of supplemental damping devices have been investigated in this review: metallic devices, friction devices, viscous fluid devices, and viscoelastic devices. Although numerous devices installation techniques available, more precisely, devices installation approaches have been reviewed in this paper, including Analysis and Redesign approach (Lavan A/R), standard placement approach, simplified sequential search algorithm, and Takewaki approach.

scholarly journals Seismic Performance of Strengthened Masonry Structures: Actual Behaviour of Buildings in Norcia and Campi Alto During the 2016 Central Italy Seismic Sequence

2021 ◽  
Author(s):  
Romina Sisti ◽  
Marco Di Ludovico ◽  
Antonio Borri ◽  
Andrea Prota
Keyword(s):  
Critical Analysis ◽  
Central Italy ◽  
Structural Response ◽  
Seismic Action ◽  
Masonry Structures ◽  
Seismic Sequence ◽  
The Past ◽  
Gravity Load ◽  
Umbria Region ◽  
Engineering Department

Abstract The structural response of unreinforced masonry buildings designed for gravity load only or with reference to obsolete seismic provisions is widely studied in the literature in order to define proper strengthening strategies and solution to mitigate the seismic risk. However, the critical analysis of the effectiveness of past used strengthening solution is still lacking. To fill such gap, the present study deals with the evaluation of the seismic performances of buildings in the historical centre of Norcia and Campi Alto struck by the 2016 central Italy seismic sequence. A large part of these buildings was strengthened between 1980 and 2000 during the reconstruction processes following previous earthquakes occurred in 1979 and 1997. The strengthened buildings in Norcia reported limited damage while a significant and widespread level of damage was detected on several strengthened buildings in the hamlet of Campi Alto. The study focuses on such latter aspect with the aim of investigating on the reasons of such unsatisfactory behaviour. Thus, a comparison between seismic action experienced by buildings in Norcia and Campi Alto is initially analysed along with the evaluation of the main vulnerabilities of these buildings. Then, 20 projects of strengthening interventions submitted to the Civil Engineering Department of the Umbria Region between 1984 and 2012 have been herein analysed and discussed in order to focus on the effectiveness of the strengthening solution adopted in the past. The analyses of such projects and of the empirical damage detected after the 2016 seismic sequence is a unique opportunity to derive useful information for future applications.

scholarly journals From the Efficiency of Nature to Parametric Design. A Holistic Approach for Sustainable Building Renovation in Seismic Regions

2019 ◽  
Vol 11 (5) ◽  
pp. 1227 ◽  
Author(s):  
Sebastiano D’Urso ◽  
Bruno Cicero
Keyword(s):  
Seismic Vulnerability ◽  
Parametric Design ◽  
Holistic Approach ◽  
Building Stock ◽  
Structural Shape ◽  
Sustainable Building ◽  
Existing Building ◽  
Low Performance ◽  
The 1960S ◽  
Stability Energy

Cities are growing dramatically. At the same time, we are witnessing the obsolescence of the existing building stock due to its low performance in terms of structural stability, energy efficiency and, last but not least, beauty. Especially in Italy, a highly seismic country, most of the buildings erected between the 1950s and the 1980s are not only earthquake-prone but also aesthetically unpleasant. In this perspective, the urgency of improving the existing building stock in terms of seismic vulnerability opens up the opportunity to also work on its architectural image. This article draws from the assumption that the search for beauty represents an important and often neglected dimension of the search for sustainability. In particular, the presented study suggests and combines the use of parametric design and the structural shape of steel exoskeletons to renovate a typical earthquake-prone apartment block from the 1960s in Italy. The results show that the proposed parametric approach can provide and select different effective renovation solutions.

Dynamics of activity syntaxonomic centres of Russia and processes of their integration

2017 ◽  
pp. 119-124
Author(s):  
B. M. Mirkin ◽  
L. G. Naumova
Keyword(s):  
Far East ◽  
Technical Information ◽  
East Siberia ◽  
Saint Petersburg ◽  
Code Of Phytosociological Nomenclature ◽  
Union Institute ◽  
History Of ◽  
The 1960S ◽  
Number Of Publications

The history of «rooting» and current state of the Braun-Blanquet approach in Russia are discussed. The process began only in the 1960s, when a more favorable climate has developed in Soviet science, and researches showed interest in the following international principles of vegetation classification. However, at that time they used, as a rule, palliative options in which «Russian» criteria (dominants) were combined with «floristic» ones. As a rule, such schemes were not successful and gave rise to imbalances in syntaxonomy. After the year 1981, when the VI All-Union conference on the classification of vegetation was held in Ufa, Soviet geobotany moved to a «strict version» of the Braun-Blanquet approach. However, at that period there were no journals in the USSR that were ready to published papers with phytosociological tables. For this reason, phytocenologists have used the resources of All-Union Institute of scientific and technical information (VINITI), which provided a free-accepted manuscript deposit, published abstracts of these papers in Refereed journal and for a modest fee sent copies to all interested specialists. The data of the deposited papers became a base for the first variant of the Prodromus of vegetation of Russia, which included 72 classes, 148 orders, 309 alliances and 74 suballiances. Since the year 2001, when the journal «Vegetation of Russia» was organized in Saint-Petersburg, both the high professional level of editorial board and the competent reviewers provide the publication of papers in strict accordance with the Braun-Blanquet approach (including the «International code of phytosociological nomenclature»), that greatly stimulated the development of syntaxonomy in Russia. Five syntaxonomic centers (Far East-Siberia, Ufa, Saint-Petersburg, Togliatti, Bryansk) have been formed. The information of their publication activity (see Table) for the periods 2001–2005, 2006–2011 and 2012–2016 years in all centres (in particular in the Far East-Siberia and Ufa) shows the number of publications is constantly increasing. This gives the hope that in the foreseeable future the Russian syntaxonomists will be able to materialize the multi-volume edition «The Vegetation of Russia».

Self-centering seismic-resistant structures: Historical overview and state-of-the-art

2021 ◽  
pp. 875529302110575
Author(s):  
Chiyun Zhong ◽  
Constantin Christopoulos
Keyword(s):  
State Of The Art ◽  
Future Research ◽  
Historical Overview ◽  
Structural Elements ◽  
Historical Structures ◽  
Seismic Resistant ◽  
The 1960S ◽  
Energy Dissipation Devices ◽  
Mechanical Restraints ◽  
Seismic Resilience

This state-of-the-art review provides an overview of the evolution of self-centering structures from early historical structures that inherently exhibited a recentering response to modern systems engineered for enhanced seismic resilience. From the early research investigations that were conducted since the 1960s, to the sharp increase of interest in this topic over the last two decades, self-centering seismic-resistant structures that can mitigate both damage and residual drifts following major earthquakes have seen significant advances. These systems achieve the intended self-centering response by either allowing for the rocking of primary structural elements in a controlled manner, commonly coupled with mechanical restraints and energy dissipation devices, or by including self-centering devices as main structural or supplemental structural members. To better explain the concepts and the underlying mechanics governing their seismic response, detailed schematic illustrations were developed in this article, highlighting the fundamentals behind each of these systems. This article covers a historical overview, presents the state of the research and of the art, discusses general design challenges and practical considerations, and concludes with future research needs to advance the development and broader application of self-centering systems in real structures.

A Beam-and-Column Based Macro Model for Masonry Infill Walls in RC Frames under Cyclic Loading

2011 ◽  
Vol 255-260 ◽  
pp. 193-197
Author(s):  
Jia Chao Zhang ◽  
Lei Ming Zhang ◽  
Xi La Liu
Keyword(s):  
Structural Response ◽  
Seismic Action ◽  
Rc Frame ◽  
Wall Panel ◽  
Infill Walls ◽  
Masonry Infill ◽  
Macro Model ◽  
Masonry Infill Walls ◽  
Rc Frames ◽  
Proposed Model

Reinforced concrete (RC) frame with masonry infill walls is a very common structural system in low and medium rise buildings. The infill walls are usually considered as non-structural components in the design or assessment of buildings. However, many damages in earthquakes have shown that the infill walls can significantly change the structural response to seismic action. Consequently the evaluation of the seismic performance of RC frame with masonry infill walls becomes very important, and also turns to be a major challenge for structure engineers. In this paper a beam-and-column (BAC) macro model for walls is proposed to simulate the masonry infill walls in RC frames. In this model, the masonry panel is replaced by an equivalent rigid frame which is made up of some beam-and-column members. The geometric parameters of each member can be determined simply by equivalent stiffness combined with the original dimensions of wall panel. The physical characteristics are described directly by material properties of wall panel under investigation. To validate the rationality of proposed model, a masonry-infilled RC frame under cyclic reversed loading is analyzed by the proposed model. The results, including crack pattern, load versus displacement relation are then compared with the experiment response. Good agreements are found.

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