Characterisation of Portuguese RC precast industrial building stock

The construction of a vulnerability model requires reliable information on the features of the buildings in the study. The purpose of this work is the characterisation of the precast industrial buildings in Portuguese industrial park, based on the survey of 73 design projects of existing buildings. The collected data are based on a previous study on the features that influence the seismic response of this type of buildings. The parameters collected are associated with the global geometry and specific elements characteristics (e.g., column dimensions, reinforcement ratios, and connections details), to the mechanical properties of the materials and other parameters that can give some important information in the characterisation of the buildings (e.g., construction year and localization). In the end, a comparison with other available databases, namely, from Italy and Turkey, is done in order to conclude about the similarity. This information is important to define representative experimental specimens and numerical simulation to conduce seismic risk analysis.publishe

Seismic design of RC precast industrial building with cladding panels

In this thesis is analysed reinforced precast industrial building on the seismic impact\ud according to standard SIST EN-1998-2:2006. Thesis deals with structural system and\ud claddind panels and about non–structual elements and Eurocode. The work is based on\ud behavior of the structure along with the facade panels and made a number of cases. Here\ud we were interested in connections between the supportin structure and facade panels, which\ud has been studied in the context of the European project SAFECLADDING. This project has\ud made an extensive study of the contacts, which are in common practice in European\ud construction. From the data obtained in the studies was a typical connection modeled and\ud used in the analysis. To yield the best results, the structure has been analysed with non –\ud linear analysis. The results of analysis on our assumptions determine what can withstand\ud seismic forces the structure

Defining structural robustness under seismic and simultaneous actions:an application to precast RC buildings

The increasing complexity of urban systems is making robustness a crucial requirement for structural design. The paper deals with the concept of robustness of civil structures against extreme events. After a brief literature survey, a novel point of view to robustness assessment is proposed, fitting the most accepted robustness definition. The proposed approach is discussed and compared with other methodologies for quantifying structural robustness. Thus, the methodology is developed and applied to an existing precast industrial building case study, assumed to be prone to seismic and wind hazards. In particular, the case study is assumed to be located in Emilia, Italy, where a significant earthquake occurred in 2012, causing relevant damage to gravity load designed industrial buildings. Three structural options are discussed, namely a simple supported beam–column connection (gravity load designed solution) and two pinned connections (seismic designed solution), where only one of them satisfies the current structural code requirements. The results are discussed in terms of robustness quantification, by means of a robustness matrix. The authors envisage that this approach can be effectively adopted for portfolios of existing structures, to prioritize retrofitting interventions, aimed at maximizing the overall risk mitigation with limited economic resources. © 2015 Springer Science+Business Media Dordrech

Seismic precast: seismic performance assessment of existing precast industrial buildings

No abstract available.publishe

Out-of-plane capacity of cladding panel-to-structure connections in one-story R/C precast structures

AbstractThe interaction between cladding panels and the main structure is a crucial point to assess the seismic response, and above all the structural safety, of RC precast industrial building. In the past, connections were often designed to allow construction tolerances and to accommodate both thermal and wind-induced displacements. The lack of specific details to allow relative in-plane displacements between cladding panels and the main structure often led to the participation of cladding panels in the structure seismic-resistant system with consequent connection failures. In the last decades, a lot of experimental tests were performed to investigate the in-plane performance of panel connections, and some design recommendations have been developed accordingly. In the out-of-plane direction, the connections were often considered to be infinitely rigid and not to suffer any damage by the seismic load. This work deals with the out-of-plane response of panel-to-structure connections for vertical panels typical of industrial and commercial precast buildings. Both standard hammer-head strap and new devices, called SismoSafe, were investigated. Tests were performed in the Structures and Materials Testing Laboratory of the Department of Civil and Environmental Engineering of Florence, where a specific setup was designed to perform cyclic and monotonic tests on the connection devices. Standard connections showed a rather limited resistance, while the innovative connections exhibited a high out-of-plane resistance. Numerical analyses were also performed on a case study building to evaluate the distribution of the out-of-plane demand on the connections

Seismic Risk Analysis of Revenue Losses, Gross Regional Product and transportation systems.

Natural threats like earthquakes, hurricanes or tsunamis have shown seri- ous impacts on communities. In the past, major earthquakes in the United States like Loma Prieta 1989, Northridge 1994, or recent events in Italy like L’Aquila 2009 or Emilia 2012 earthquake emphasized the importance of pre- paredness and awareness to reduce social impacts. Earthquakes impacted businesses and dramatically reduced the gross regional product. Seismic Hazard is traditionally assessed using Probabilistic Seismic Hazard Anal- ysis (PSHA). PSHA well represents the hazard at a specific location, but it’s unsatisfactory for spatially distributed systems. Scenario earthquakes overcome the problem representing the actual distribution of shaking over a spatially distributed system. The performance of distributed productive systems during the recovery process needs to be explored. Scenario earthquakes have been used to assess the risk in bridge networks and the social losses in terms of gross regional product reduction. The proposed method for scenario earthquakes has been applied to a real case study: Treviso, a city in the North East of Italy. The proposed method for scenario earthquakes requires three models: one representation of the sources (Italian Seismogenic Zonation 9), one attenuation relationship (Sa- betta and Pugliese 1996) and a model of the occurrence rate of magnitudes (Gutenberg Richter). A methodology has been proposed to reduce thou- sands of scenarios to a subset consistent with the hazard at each location. Earthquake scenarios, along with Mote Carlo method, have been used to simulate business damage. The response of business facilities to earthquake has been obtained from fragility curves for precast industrial building. Fur- thermore, from business damage the reduction of productivity has been simulated using economic data from the National statistical service and a proposed piecewise “loss of functionality model”. To simulate the economic process in the time domain, an innovative businesses recovery function has been proposed. The proposed method has been applied to generate scenarios earthquakes at the location of bridges and business areas. The proposed selection method- ology has been applied to reduce 8000 scenarios to a subset of 60. Subse- quently, these scenario earthquakes have been used to calculate three system performance parameters: the risk in transportation networks, the risk in terms of business damage and the losses of gross regional product. A novel model for business recovery process has been tested. The proposed model has been used to represent the business recovery process and simulate the effects of government aids allocated for reconstruction. The proposed method has efficiently modeled the seismic hazard using scenario earthquakes. The scenario earthquakes presented have been used to assess possible consequences of earthquakes in seismic prone zones and to increase the preparedness. Scenario earthquakes have been used to sim- ulate the effects to economy of the impacted area; a significant Gross Regional Product reduction has been shown, up to 77% with an earthquake with 0.0003 probability of occurrence. The results showed that limited funds available after the disaster can be distributed in a more efficient way

The Emilia earthquakes: Report and analysis on the behavior of precast industrial buildings from a field mission

A series of earthquakes, the highest of magnitude Mw 5.9, hit a portion of the Po Valley in Northern Italy, which was only recently classified as seismic. The paper reports the findings and the lessons learnt from a preliminary field survey which was conducted immediately after the second event. As a result of the economic attitude of the affected area, and possibly of the characteristics of the event, an unprecedented number of industrial precast buildings were affected, resulting into most of the casualties as well as in large economic losses. Whereas most of the damaged and collapsed buildings were designed for gravity loads only, evidence of poor behavior of some precast buildings designed according to seismic provisions were discovered. The paper provides a description of the performance of precast buildings, highlighting the deficiencies that led to their poor behavior as well as some preliminary .recommendationsJRC.G.5-European laboratory for structural assessmen

Effect of Column Section Parameters on Fragility of Precast Industrial Buildings

DergiPark: 246016trakyafbdBu çalışmada Türkiye’deki tek katlı prefabrik sanayi yapıları için hasar olasılık eğrileri analitik yolla elde edilmiştir. Kolon kesit parametrelerinin hasar görebilirliğe etkisinin değerlendirilebilmesi amacıyla kolon boyutu, boyuna donatı oranı, etriye aralığı parametrelerine bağlı olarak 8 tipik prefabrik sanayi yapısı modeli kullanılmıştır. Doğrusal ötesi zaman tanım alanında analiz için 28 depreme ait 360 ivme kaydı seçilmiştir. Yer hareketi parametresi olarak lognormal dağıldığı kabul edilen PGV seçilmiştir. Yapısal tepki parametresi olarak kritik kesitte beton ve çeliğin birim şekil değiştirmelerine bağlı olarak hesaplanan yatay deplasman kullanılmıştır. Seçilen parametrelerin, prefabrik yapıların hasar görebilirliği üzerinde etkili olduğu belirlenmiştirThe aim of this study to obtain analytical fragility curves for precast industrial buildings in Turkey. In order to determine the effect of column section parameters on fragility curves, 8 typical precast buildings are considered according to column section, longitudinal reinforcement ratio and stirrup spacing. 360 ground motions, selected from 28 different earthquakes, are used for nonlinear time history analysis. Using the structural response parameters and ground motion parameter PGV, fragility curves are constructed assuming two-parameter lognormal distrubition. Lateral displacement is selected as structural response parameter. Fragility curves are suggested for immediate occupancy, life safety and collapse prevention damage levels. Results show that, concerned parameters affect fragility of precast industrial building

Evaluation of the Seismic Capacity of Existing Moment Resisting Frames by a Simplified Approach: Examples and Numerical Application

The capacity of a structure can be assessed using inelastic analysis, requiring sophisticated numerical procedures such as pushover and incremental dynamic analyses. A simplified method for the evaluation of the seismic performance of steel moment resisting frames (MRFs) to be used in everyday practice has been recently proposed. This method evaluates the capacity of buildings employing an analytical trilinear model without resorting to any non−linear analysis. Despite the methodologies suggested by codes, the assessing procedure herein described is of easy application, also by hand calculation. Furthermore, it constitutes a suitable tool to check the capacity of the buildings designed with the new seismic code prescriptions. The proposed methodology has been set up through a large parametric analysis, carried out on 420frames designed according to three different approaches: the theory of plastic mechanism control (TPMC), ensuring the design of structures showing global collapse mechanism (GMRFs), the one based on the Eurocode 8 design requirements (SMRFs), and a simple design against horizontal loads (OMRFs) without specific seismic requirements. In this paper, some examples of the application of this simplified methodology are proposed with references to structures supposed to exhibit global, partial and soft storey mechanism

Optimal sliding friction coefficient for isolated bridges in different soil conditions

The work evaluates the optimal properties of friction pendulum system (FPS) bearings for the seismic protection of bridge piers under earthquake excitations having different frequency characteristics representative of different soil conditions in order to reduce the seismic vulne-rability of infrastructures. A two-degree-of-freedom model is adopted to describe, respective-ly, the response of the infinitely rigid deck isolated by the FPS devices and the elastic behavior of the pier. By means of a non-dimensional formulation of the motion equations, a wide parametric analysis for several structural parameters is carried out. Seismic excitations, modelled as time-modulated filtered Gaussian white noise random processes having different intensities and frequency contents, are considered. Specifically, the filter parameters, which control the frequency contents, are properly calibrated to reproduce stiff, medium and soft soil conditions, respectively. Finally, the optimum values of the sliding friction coefficient able to minimize the pier displacements with respect to the ground are derived as a function of the structural properties, of the seismic input intensity and of the soil condition