BETONARME BINALARIN SISMIK PERFORMANS INDEKSININ BULANIK MANTIK ILE TAYINI

A proper use of the resources has become the prime target of the economy circles nowadays. In this connection, an optimal use of the resources in the construction industry is of a great importance. In a construction project, a vast number of processes are involved and each of them requires many different resources, namely, labor, machinery, materials, finance, etc. The size of the construction projects is relatively large and these projects are fairly complicated. One should not think that the resources are to be available at the desired time and at a prescribed amount during the process of the implementation of the project. Therefore, use of the resources also needs a stage of planning. These projects can conveniently programmed by the so-called resource constrained project scheduling techniques. In this work, an algorithm based on a heuristic approach with priority rules was developed in the Visual Basic language and tested on a project applied to the construction of building for primary school in Turkey. The project comprises 79 activities each involving 11 different resources. Different programs for the cases of constrained and unconstrained resources were developed. The overall period it takes the project to be completed was found to be 226 days for the case of unconstrained resources and 260 days for the case of under constrained resources.Bu çalışmada, bulanık mantık Japon Sismik İndeks Yöntemine uygulanmıştır. Sismik Performans İndeksi (IS), bulanık mantık kullanılarak analiz edilmiştir. Sismik İndeks Yöntemi, Türkiye’deki betonarme yapılarda karşılaşılan yapısal düzensizlikler dikkate alınarak bazı eklentiler yapılmıştır. Bu prosedür, İstanbul-Avcılar’da bulunan hasar görmüş bir betonarme binaya uygulanmıştır. Sayısal analiz sonuçları bu çalışmada sunulmuştur

Would RC wide-beam buildings in Spain have survived Lorca earthquake (11-05-2011)?

Lorca earthquake (11-05-2011) is most destructive event recorded in Spain, causing nine fatalities and other severe consequences. Its important intensity was rather unexpected, and serious concern arose regarding risk of building stock in Spain. This paper analyzes performance, under Lorca earthquake, of RC buildings with one-way slabs with wide beams. This construction type is chosen for its high vulnerability and for being vastly widespread in Spain. This study is conducted on 3 and 6-story prototype representative buildings. These buildings are designed for three major seismic zones in Spain: low seismicity, moderate seismicity (as Lorca) and medium seismicity (as Granada). Seismic performance under Lorca earthquake is numerically investigated through nonlinear time-history analyses. Results show that buildings designed without any seismic provision (i.e. those in low seismicity zones) do not survive Lorca record, even with cooperation of masonry infill walls. Buildings with seismic design (i.e. those in Lorca and Granada zones) can survive Lorca earthquake only with collaboration of infill walls. To raise reliability of these conclusions, a sensitivity analysis to most influencing parameters is conducted.Postprint (author's final draft

An Assessment to Benchmark the Seismic Performance of a Code-Conforming Reinforced-Concrete Moment-Frame Building

This report describes a state-of-the-art performance-based earthquake engineering methodology that is used to assess the seismic performance of a four-story reinforced concrete (RC) office building that is generally representative of low-rise office buildings constructed in highly seismic regions of California. This “benchmark” building is considered to be located at a site in the Los Angeles basin, and it was designed with a ductile RC special moment-resisting frame as its seismic lateral system that was designed according to modern building codes and standards. The building’s performance is quantified in terms of structural behavior up to collapse, structural and nonstructural damage and associated repair costs, and the risk of fatalities and their associated economic costs. To account for different building configurations that may be designed in practice to meet requirements of building size and use, eight structural design alternatives are used in the performance assessments. Our performance assessments account for important sources of uncertainty in the ground motion hazard, the structural response, structural and nonstructural damage, repair costs, and life-safety risk. The ground motion hazard characterization employs a site-specific probabilistic seismic hazard analysis and the evaluation of controlling seismic sources (through disaggregation) at seven ground motion levels (encompassing return periods ranging from 7 to 2475 years). Innovative procedures for ground motion selection and scaling are used to develop acceleration time history suites corresponding to each of the seven ground motion levels. Structural modeling utilizes both “fiber” models and “plastic hinge” models. Structural modeling uncertainties are investigated through comparison of these two modeling approaches, and through variations in structural component modeling parameters (stiffness, deformation capacity, degradation, etc.). Structural and nonstructural damage (fragility) models are based on a combination of test data, observations from post-earthquake reconnaissance, and expert opinion. Structural damage and repair costs are modeled for the RC beams, columns, and slabcolumn connections. Damage and associated repair costs are considered for some nonstructural building components, including wallboard partitions, interior paint, exterior glazing, ceilings, sprinkler systems, and elevators. The risk of casualties and the associated economic costs are evaluated based on the risk of structural collapse, combined with recent models on earthquake fatalities in collapsed buildings and accepted economic modeling guidelines for the value of human life in loss and cost-benefit studies. The principal results of this work pertain to the building collapse risk, damage and repair cost, and life-safety risk. These are discussed successively as follows. When accounting for uncertainties in structural modeling and record-to-record variability (i.e., conditional on a specified ground shaking intensity), the structural collapse probabilities of the various designs range from 2% to 7% for earthquake ground motions that have a 2% probability of exceedance in 50 years (2475 years return period). When integrated with the ground motion hazard for the southern California site, the collapse probabilities result in mean annual frequencies of collapse in the range of [0.4 to 1.4]x10 -4 for the various benchmark building designs. In the development of these results, we made the following observations that are expected to be broadly applicable: (1) The ground motions selected for performance simulations must consider spectral shape (e.g., through use of the epsilon parameter) and should appropriately account for correlations between motions in both horizontal directions; (2) Lower-bound component models, which are commonly used in performance-based assessment procedures such as FEMA 356, can significantly bias collapse analysis results; it is more appropriate to use median component behavior, including all aspects of the component model (strength, stiffness, deformation capacity, cyclic deterioration, etc.); (3) Structural modeling uncertainties related to component deformation capacity and post-peak degrading stiffness can impact the variability of calculated collapse probabilities and mean annual rates to a similar degree as record-to-record variability of ground motions. Therefore, including the effects of such structural modeling uncertainties significantly increases the mean annual collapse rates. We found this increase to be roughly four to eight times relative to rates evaluated for the median structural model; (4) Nonlinear response analyses revealed at least six distinct collapse mechanisms, the most common of which was a story mechanism in the third story (differing from the multi-story mechanism predicted by nonlinear static pushover analysis); (5) Soil-foundation-structure interaction effects did not significantly affect the structural response, which was expected given the relatively flexible superstructure and stiff soils. The potential for financial loss is considerable. Overall, the calculated expected annual losses (EAL) are in the range of $52,000 to$97,000 for the various code-conforming benchmark building designs, or roughly 1% of the replacement cost of the building ($8.8M). These losses are dominated by the expected repair costs of the wallboard partitions (including interior paint) and by the structural members. Loss estimates are sensitive to details of the structural models, especially the initial stiffness of the structural elements. Losses are also found to be sensitive to structural modeling choices, such as ignoring the tensile strength of the concrete (40 EAL) or the contribution of the gravity frames to overall building stiffness and strength (15 change in EAL). Although there are a number of factors identified in the literature as likely to affect the risk of human injury during seismic events, the casualty modeling in this study focuses on those factors (building collapse, building occupancy, and spatial location of building occupants) that directly inform the building design process. The expected annual number of fatalities is calculated for the benchmark building, assuming that an earthquake can occur at any time of any day with equal probability and using fatality probabilities conditioned on structural collapse and based on empirical data. The expected annual number of fatalities for the code-conforming buildings ranges between 0.05*10 -2 and 0.21*10 -2 , and is equal to 2.30*10 -2 for a non-code conforming design. The expected loss of life during a seismic event is perhaps the decision variable that owners and policy makers will be most interested in mitigating. The fatality estimation carried out for the benchmark building provides a methodology for comparing this important value for various building designs, and enables informed decision making during the design process. The expected annual loss associated with fatalities caused by building earthquake damage is estimated by converting the expected annual number of fatalities into economic terms. Assuming the value of a human life is$3.5M, the fatality rate translates to an EAL due to fatalities of $3,500 to$5,600 for the code-conforming designs, and $79,800 for the non-code conforming design. Compared to the EAL due to repair costs of the code-conforming designs, which are on the order of$66,000, the monetary value associated with life loss is small, suggesting that the governing factor in this respect will be the maximum permissible life-safety risk deemed by the public (or its representative government) to be appropriate for buildings. Although the focus of this report is on one specific building, it can be used as a reference for other types of structures. This report is organized in such a way that the individual core chapters (4, 5, and 6) can be read independently. Chapter 1 provides background on the performance-based earthquake engineering (PBEE) approach. Chapter 2 presents the implementation of the PBEE methodology of the PEER framework, as applied to the benchmark building. Chapter 3 sets the stage for the choices of location and basic structural design. The subsequent core chapters focus on the hazard analysis (Chapter 4), the structural analysis (Chapter 5), and the damage and loss analyses (Chapter 6). Although the report is self-contained, readers interested in additional details can find them in the appendices

Megastructures: a great-size solution for affordable housing. The case study of Rome

During the 70’s and 80’s, affordable housing production in Europe faced the huge emergency caused by rising urbanization. In suburban areas of European main cities, megastructures appeared, drawing visible marks in urban fabric. Megastructures were planned to synthesize residential functions and all existing services of traditional city in unique buildings. Nowadays, these buildings are affected by bad physical conditions and they are no longer able to satisfy the needs of the contemporary demand. The proposed paper investigates the genesis of housing megastructures with particular regards to the Italian case and council housing districts realized in Rome within the 1st public plan for council and affordable housing (1964), an original plan for the settlement of 700,000 inhabitants. A focus will be proposed concerning the differences between megastructures and traditional big buildings and the main connections between the spread of great-size buildings and the industrialization and automatization of construction techniques. An insight about possible future regenerations intervention is suggested

Present and future resilience research driven by science and technology

Community resilience against major disasters is a multidisciplinary research field that garners an ever-increasing interest worldwide. This paper provides summaries of the discussions held on the subject matter and the research outcomes presented during the Second Resilience Workshop in Nanjing and Shanghai. It, thus, offers a community view of present work and future research directions identified by the workshop participants who hail from Asia – including China, Japan and Korea; Europe and the Americas

A methodology on the treatment of the issue of Cultural heritage restoration in Tirana, period 1920-’40 BIM modeling, Seismic simulation and Theoretical interpretatios

The history has left its mark on the Albanian culture and society, from the “Roman Empire, Greek colonies, Turkish Empire, to the Balkan and World Wars”. Indescribable is the influence of Italian designers between 1920 and 1940. The architecture of the center of Tirana, reflected mainly along the main boulevard buildings that divides the city into two parts, is an “undeniable proof of the symbiotic process” that has always characterized the relationship between Italian and Albanian culture in all dimensions. The cultural heritage buildings of Tirana’s case provide structures and monuments of great value, since they are proof of historic forms of life and the history of modern societies, and show the existence of a tangible cultural identity. The architectural heritage adds character to its surroundings, is an integral part of the city, and is also a valuable tourism resource. The study will be carried out through theoretical approaches initially and literature research, while later the methodology will take shape through the treatment of some cases of studies, which have not been previously studied in this specific context. The Albanian context has shown a lack of cooperation in a team of experts or governments have made this contribution even more fragile. To achieve this goal, the right atmosphere of cooperation between experts must be created, to consider their diverse perspectives. On the other hand, this research aims to raise awareness of Tirana's cultural heritage past by fostering a debate on cultural heritage and its future within a structured heritage framework. The study tends to stimulate the process of digitalization by creation of 3D models including BIM, in such a way as to create accessible database of materials, elements, combined architectural and structural models, database for additions and retrofitting’s. Those buildings that surround us today define the spaces of our cities which still more tell us how we were, how to judge the past and above of all how we can project the future.La storia ha lasciato il suo marchio nella società e la cultura albanese da le colonie Greche al Impero Romano dal Impero Ottomano alle guerre balcaniche fino alle guerre mondiali. Descrivibili sono le tracce e l’influenza lasciata dagli architetti Italiani tra il 1920 al 1940. L’Architettura del centro di Tirana, riflessa principalmente lungo il viale principale il quale decide la città in due parti e prova indelebile del processo simbiotico che ha caratterizzato le relazioni culturali tra Italia e Albania in tutte le dimensioni. La ricerca e l’analisi dei materiali trovati al archivio del istituto Tecnico di Tirana e anche ne archivio del Istituto Luce, specificamente negli archivi del L. Luigi e G. Fiorini sono stati d’aiuto nel capire meglio la visione degli architetti Italiani per Tirana. Oggigiorno questi disegni servono come punto di riferimento per architetti, ingegneri e restauratori per quanto riguarda al bisogno di ricostruzione e intervento di manutenzione che questi edifici hanno. Dopo la seconda Guerra Mondiale questi edifici venivano percepiti come memoria e segno del invasione straniera, negli ultimi 30 anni queste ideologie e superstizioni furono rimpiazzate da un più pacifico processo evolutivo. Costruitesi tra gli anni 20-40 per altri scopi dopo la liberazione cambiarono destinazione d’uso trasformandosi in Università, centri di studi, sedi per Ministeri diventando cosi parte inseparabile per la vita di ogni giorno e entrando a far parte nella storia della citta, intersecandosi e comunicando tra di loro. Oggigiorno questo patrimonio Storico-culturale condivisa ha aiutato a cambiare la percezione iniziale. Questo patrimonio culturale di Tirana fornisce strutture di grande valore si come sono prova di storia e delle forme della vita e della storia moderna della società. Il patrimonio architettonico da un distintivo aspetto al contesto circostante a uno degli elementi essenziali della città e ancor più diventa una risorsa turistica. Oggigiorno questo patrimonio culturale architettonica viene riconosciuto come fragile e insostituibile, patrimonio che va preservata e trasmessa alle future generazioni. Comunque le politiche di protezione non sempre sono efficienti come lo dovrebbe essere alle quali si aggiunge un disinteresse cittadino e un clima socio-politica molto avversa. La performanza degli edifici patrimonio culturale dopo i terremoti e una preoccupazione di tante figure professionali di diverse discipline. Anche se tutti predicono la salvaguardia di questo patrimonio culturale – architettonica dal rischio danneggiamento a causa dei terremoti, il prevedibile danneggio di questi valori estetici di questi edifici (causa le addizioni e processi di riqualificazione) viene ostacolato da una decisione consensuale sul bisogno di intervento o meno nel salvaguardare questi tesori. Questo deriva dalla mancanza di una solida base di principi, nel tenere conto dei fattori che incidono sulla riduzione del rischio sismico negli edifici, per il consolidamento della struttura e nel contempo il danneggiamento dei valori attribuiti a specifici tecniche di intervento. L’età di questi edifici si sta avvicinando ai 100° anni fatto che ci rende consapevoli della grandezza degli architetti di quel periodo. Riguardo a questo studio tenta di definire i principi e i segreti della semplicità strutturale e la reinterpretazione teorica degli argomenti strutturali. Le configurazioni in piano e altezza, degli elementi strutturali più usati nel periodo e l’abilita di sopportare a un ampio numero di eventi sismici. La visione strategica di questo studio e di sviluppare una dettagliata metodologia la quale servirà come manuale di riferimento nel indirizzare sia problemi di restauro anche i problemi del analisi strutturale del patrimonio culturale con i principi delle carte internazionali sul restauro

Great East Japan Earthquake, JR East Mitigation Successes, and Lessons for California High-Speed Rail, MTI Report 12-37

California and Japan both experience frequent seismic activity, which is often damaging to infrastructure. Seismologists have developed systems for detecting and analyzing earthquakes in real-time. JR East has developed systems to mitigate the damage to their facilities and personnel, including an early earthquake detection system, retrofitting of existing facilities for seismic safety, development of more seismically resistant designs for new facilities, and earthquake response training and exercises for staff members. These systems demonstrated their value in the Great East Japan Earthquake of 2011 and have been further developed based on that experience. Researchers in California are developing an earthquake early warning system for the state, and the private sector has seismic sensors in place. These technologies could contribute to the safety of the California High-Speed Rail Authority’s developing system, which could emulate the best practices demonstrated in Japan in the construction of the Los Angeles-to-San Jose segment

Sustainable building design

Sustainable building design has become a wide and multidisciplinary research endeavor including mechanical, electrical, electronic, communication, acoustic, architectural, and structural engineering. It involves the participation of owners, contractors, suppliers and building users. There has been a lot of talk about sustainable buildings in the past few years. Most of the published research is concerned with saving energy and water and making the buildings more environmentally friendly by, say, reducing the carbon emissions. In this article, sustainable building design is reviewed from the viewpoint of structural engineering. Different strategies presented in the literature are summarized. Finally, the authors argue that the next big leap in sustainable building design should come from the integration of the smart structure technology including the use of hybrid and semi-active vibration controllers that can result in substantially lighter and more efficient structures