2nd Croatian Conference on Earthquake Engineering ‒ 2CroCEE最新文献

{"title":"PHYSICAL AND VIRTUAL EXPERIMENTAL INVESTIGATION OF SELF-CENTRING CONCENTRICALLY BRACED FRAMES","authors":"Borjan Petreski, Igor Gjorgjiev","doi":"10.5592/co/2crocee.2023.42","DOIUrl":"https://doi.org/10.5592/co/2crocee.2023.42","url":null,"abstract":"The self-centring concentrically braced frames (SC-CBF) present an innovative structural typology for improved behaviour of the steel structures to earthquake loading. Namely, the SC-CBFs present an advanced technological solution for minimization of the residual drifts at concentrically braced frames which are quite substantial following high intensity seismic action. This structural type’s main characteristic is the re-centring of the frame following the earthquake loading in the initial vertical position, thus reducing the post-earthquake cost and time for retrofitting. It also reduces the material used for repair since the only elements needing retrofitting remain the diagonal braces that undergo many cyclic loadings under the earthquake excitation and develop plastic hinges. However, in order to validate this behaviour, many experimental investigations are required. For that purpose, this study addresses previous, current and future experimental testing considerations and shows the results and potential findings. Firstly, the previous experimental studies involving quasi-static and shake table testing are presented. Then, a virtual experimental procedure is presented in order to tackle the most demanding aspects of calibration and parameter estimation for the simulation of dynamic structural response. The various types of experimental procedures are then combined in order to form a complete methodology for estimation of the main characteristics of the novel system and proceeding to a code conforming evaluation procedure. A combination of these experimental methodologies is the ultimate method for developing reliable numerical simulation model, as well. The calibrated model is subjected to reliability analysis in order to estimate the probability of failure for predefined failure scenarios. Finally, the numerical model is used for developing several archetype structures and thorough parametric study for EC conform design procedure.","PeriodicalId":427395,"journal":{"name":"2nd Croatian Conference on Earthquake Engineering ‒ 2CroCEE","volume":"98 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124273749","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"EVALUATION OF THE LOCAL SITE EFFECTS OF THE UNESCO WORLD HERITAGE SITE OLD CITY OF DUBROVNIK (CROATIA)","authors":"D. Stanko, Tvrtko Korbar, Jakov Stanislav Uglešić, Iva Loncar, Mario Gazdek, S. Markušić","doi":"10.5592/co/2crocee.2023.35","DOIUrl":"https://doi.org/10.5592/co/2crocee.2023.35","url":null,"abstract":"The most seismically active region in Adriatic part of Croatia is the SE coastal region that have numerous cultural heritage sites. Therefore, it is important to estimate seismic risk for cultural heritage sites and to develop procedures for seismic risk assessment. These are the goals of the research project Seismic Risk Assessment of Cultural Heritage Buildings in Croatia (SeisRICHerCRO) funded by the Croatian Science Foundation. Local site effects, a known problem in earthquake engineering, play significant role in earthquake damage distribution. The old town of Dubrovnik is particularly vulnerable in terms of local site effects because the old city is built on three geomorphological and geological entities: southern bedrock ridge, central filled and flattened part (former sea embayment), and northern bedrock ridge. Apart from the last devastating historical earthquake in Dubrovnik area in 1667 of M~7), instrumentally recorded strong earthquake on 15 April 1979 M6.8 with mainshock at the epicentral distance of 105 km from Dubrovnik caused strong damage effects in the wider Dubrovnik area (intensity of VII °MSK) with incalculable damage to cultural and historical objects the old town Dubrovnik The main aim of this study is mapping of local site effects variations in the old city of Dubrovnik using old investigation data as a starting point from 1980’s, after 1979 Reconstruction of Dubrovnik. Data quality and spatial uncertainty brough by older equipment used in 1980’s compared to using novel and sophisticated geophysical research methods followed by new geological investigations will significantly improve planning and reconstruction of Dubrovnik following new microzonation maps. Definition of the seismicity and variations of the local site conditions are one of the inevitable phases of the complex process of repair and strengthening of existing structures in the old town Dubrovnik together with design seismic parameters and the seismic risk level of building inventory as a basis to define the necessary preventive measures against expected strong earthquakes in the future.","PeriodicalId":427395,"journal":{"name":"2nd Croatian Conference on Earthquake Engineering ‒ 2CroCEE","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125177408","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"GEOTECHNICAL AND GEOPHYSICAL TESTS FOLLOWING THE 2020 EARTHQUAKE-INDUCED LIQUEFACTION PHENOMENA","authors":"S. Amoroso, K. Rollins, G. Di Giulio, L. Wacha, K. Urumović, Diana Faieta, R. Filjak, D. Fontana, S. Lugli, M. Manuel, G. Milana, L. Minarelli, Marko Budić, N. Belic, Tomislav Kurečić, Luka Sorić, M. Stefani, G. Tarabusi, M. Vassallo","doi":"10.5592/co/2crocee.2023.21","DOIUrl":"https://doi.org/10.5592/co/2crocee.2023.21","url":null,"abstract":"Earthquakes and related coseismic effects at the surface, such as liquefaction and lateral spreading, can impact humans due to the resulting economic or social disruptions (e.g. slope and foundation failures, flotation of buried structures, etc.). In this respect, the 2020 Petrinja Mw6.4 earthquake (Croatia) provided many examples of liquefaction and lateral spreading, as identified by the post-earthquake field reconnaissance campaigns. The observed liquefaction cases occurred in the alluvial plains of the Kupa, Sava and Glina Rivers or along faults, with ejecta composed of sands and/or gravels of different grain size and mineralogy. The lateral spreading phenomena were observed along river embankments and roads. In this context interest in studying these different features arose, and an international research team from Italy, the United States and Croatia recently performed an intensive geological, geotechnical and geophysical campaign to assess the liquefaction susceptibility at selected sites located throughout the epicentral area (from Glina to Petrinja to Sisak). Innovative in-situ test equipment, such as the dynamic cone penetration test (DPT) for liquefied gravels and the Medusa flat dilatometer test (Medusa DMT) for liquefied sands, were employed in combination with standard in-situ tests,such as the standard penetration test (SPT), the piezocone test (CPTU), and shear wave velocity (Vs) measurements. These techniques were employed to verify their advantages relative to the existing iquefaction triggering charts and to characterize the soil properties of the buried liquefied layers and the non-liquefied crust. This paper presents preliminary results and comparisons at some of the investigated liquefaction sites.","PeriodicalId":427395,"journal":{"name":"2nd Croatian Conference on Earthquake Engineering ‒ 2CroCEE","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123717656","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"FRIBAS: A PARAMETRIC DATABASE OF BUILDING AND SOIL FEATURES INCLUDING THE FUNDAMENTAL FREQUENCY OF RESONANCE","authors":"C. Scaini, B. Petrovic, M. Gallipoli, G. Calamita, N. Tragni, C. Barnaba, M. Vona, S. Parolai","doi":"10.5592/co/2crocee.2023.57","DOIUrl":"https://doi.org/10.5592/co/2crocee.2023.57","url":null,"abstract":"The FRIBAS database collects information on the characteristics of more than 300 buildings located in southern and northeastern Italy. The characteristics comprise age, construction material, storey number and other data such as geometrical features (e.g. shape) and construction details (e.g. roof type, floor types). Such characteristics were inferred based on external and sometimes internal building inspection, combined with information provided by residents. In addition, FRIBAS includes the fundamental frequencies of buildings and foundation soil, estimated empirically using single station ambient noise measurements. The database was assembled based on data collected separately in northeastern and southern Italy on different building types (including both low to mid-rise historical and modern masonry and low to high-rise reinforced concrete buildings). The buildings were chosen also based on the possibility of accessing the interior and performing measurements. Data were harmonized into 37 fields which provide a generalized classification of building and soil parameters. FRIBAS is the first database that collects several buildings characteristics, including structural and geometrical features, together with the fundamental frequencies of buildings of and foundation soil. FRIBAS was assembled with the specific purpose of analyzing how different building parameters influence structural behavior (in particular, the fundamental period). The database is available online in open access mode under the CC 4.0 license. The collected data support the definition of different period-height relationships based on construction material and soil types. The analysis can be extended to other parameters associated with specific building types. We discuss the relevance of empirical building and soil characterization for seismic damage/risk assessment and propose potential applications of the FRIBAS database.","PeriodicalId":427395,"journal":{"name":"2nd Croatian Conference on Earthquake Engineering ‒ 2CroCEE","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115557794","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"ASSESSING LIQUEFACTION IN GRAVELLY SOILS BASED ON FIELD CASE HISTORIES","authors":"K. Rollins, Jashod Roy","doi":"10.5592/co/2crocee.2023.141","DOIUrl":"https://doi.org/10.5592/co/2crocee.2023.141","url":null,"abstract":"Gravelly soils have liquefied at multiple sites in at least 27 earthquakes over the past 130 years. These gravels typically contain more than 25% sand which lowers the permeability and makes them susceptible to liquefaction. Developing a reliable, cost-effective liquefaction triggering procedure for gravelly soils has been a challenge for geotechnical engineers. Typical SPT- or CPT-based correlations can be affected by large-size gravel particles and can lead to erroneous results. To deal with these problems, we have developed liquefaction triggering curves for gravelly soils based on (1) shear wave velocity (Vs) and (2) a large diameter cone penetrometer. With a cone diameter of 74 mm, the Chinese Dynamic Cone Penetration Test (DPT) is superior to smaller penetrometers and can be economically performed with conventional drilling equipment. Using logistic regression analysis, the DPT has been directly correlated to liquefaction resistance at sites where gravels did and did not liquefy in past earthquakes. Probabilistic liquefaction resistance curves were developed based on 137 data points from 10 different earthquakes in seven countries. Using a similar data set, probabilistic liquefaction triggering curves were also developed based on Vs measurements in gravelly soils. The Vs-based liquefaction triggering curves for gravels shift to the right relative to similar curves based on sands. New magnitude scaling factor (MSF) curves have also been developed specifically for gravel liquefaction which were found to be reasonably consistent with previous curves for sand.","PeriodicalId":427395,"journal":{"name":"2nd Croatian Conference on Earthquake Engineering ‒ 2CroCEE","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121856958","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"SEISMIC RETROFIT OF R.C. BUILDINGS IN USE THROUGH SEISMIC ISOLATION. THREE CASE STUDIES IN L'AQUILA, ITALY","authors":"M. Castellano, R. Vetturini","doi":"10.5592/co/2crocee.2023.132","DOIUrl":"https://doi.org/10.5592/co/2crocee.2023.132","url":null,"abstract":"Seismic isolation (SI) advantages for new buildings are well known: not only it allows to avoid damage of both structural and non structural elements under strong earthquake, but it mantains building functionality as well. This is possible thanks to strong reduction of accelerations and interstorey drift in the superstructure, i.e. the part of structure above the isolation layer. SI offers additional advantages for seismic retrofit of existing buildings. The main advantage is that the works can be limited at one floor (usually the basement, plus the foundation), without any strenghtening on the superstructure. Consequently, the building can be used during the retrofit works. The safety of the retrofitted building increases significantly. Reaching exactly the same safety level of a new building in the same site would be possible, but it would need some strenghtening in the superstructure, and thus is usually avoided in order to keep the building in function during the works. It is worth noting that for the seismic isolation system, the safety is the same than for a new building. The paper presents in detail three case studies of framed r.c. buildings built in the 1980s and now under retrofit with seismic isolation, that could be representative of many other buildings. During 2009 L'Aquila earthquake, those residential buildings were only slightly damaged, and immediately repaired but without any improvement of their seismic performance. Now the retrofit design is carried out for an earthquake stronger than the 2009 earthquake. Despite the buildings are in the same area (ag=0.261g for the Life Safety Limit State earthquake; ag=0.334g for the Collapse Limit State earthquake, used to design the seismic isolation system), the design spectrum is different because of different type of soil. The isolators are inserted in the basement or in the ground floor that host the garages, thus without affecting the apartments. The safety level reached in the three buildings was higher than 70% of that of new buildings in the same site, while before retrofit it was lower than 16%","PeriodicalId":427395,"journal":{"name":"2nd Croatian Conference on Earthquake Engineering ‒ 2CroCEE","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129484970","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"SEISMIC RESILIENCE OF THE SCHOOLS IN BANJA LUKA- SOME CONSTRUCTIONAL AND PREPAREDNESS ASPECTS","authors":"V. Šipka, Velibor Lalić, S. Radovanović, Cvjetko Sandić","doi":"10.5592/co/2crocee.2023.78","DOIUrl":"https://doi.org/10.5592/co/2crocee.2023.78","url":null,"abstract":"Banja Luka is a city which, in October 1969, experienced the strongest earthquake in the territory of Bosnia and Herzegovina. On that occasion 2/3 of the school buildings were severely damaged or destroyed. Banja Luka students were forced to attend that school year throughout the former Yugoslavia. Seismic risk management for schools on the territory of Banja Luka is significant from the aspect of protecting students as a vulnerable category of society. It is also important observing the fact that school facilities are used as facilities for temporary mass accommodation of the affected population during emergencies. Examining the level of earthquake protection, i.e. seismic resilience of the schools in Banja Luka, as a city with a high seismic hazard, implies the resistance of school buildings (material resilience) but also the preparedness of school communities (administration, students and teachers) to react properly in the event of an earthquake (non-material resilience). The results of the research indicate weaknesses in both the material and non-material resilience of schools. The structural aspects of school resilience include the seismic hazard of the area, the soil at school locations in terms of the expected seismic effect, the age and poor maintenance of the buildings, and the undefined ownership of school buildings. Regarding non-structural resistance, a low level of carrying out preventive activities such as education, training and practical exercises for dealing with earthquakes was identified as well as inadequate planning documentation.","PeriodicalId":427395,"journal":{"name":"2nd Croatian Conference on Earthquake Engineering ‒ 2CroCEE","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129567067","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"SEISMIC RISK IN THE DISTRICT/MUNICIPALITY OF DURRËS","authors":"M. Baballëku, Klajdi Shaholli, Rikard Luka, Genti Qirjazi, Renti Haziraj","doi":"10.5592/co/2crocee.2023.107","DOIUrl":"https://doi.org/10.5592/co/2crocee.2023.107","url":null,"abstract":"After the seismic events of 2019, one of the first difficulties encountered was finding and focusing attention on the most damaged areas. It is understood that the aid of the affected population was forthcoming, but the impact of the panic and the overall chaotic circumstances left little opportunity to focus proper attention on the areas with greater damage. A document with analysis, findings and conclusions that showed in advance the areas with the highest risk and their treatment in the territory was missing. By trying to evaluate every clarifying and helpful element in damage assessment even in disaster situations, the consequences that occurred, their analysis and interpretation take on significant importance in risk assessment. This paper is focused at two main topics: 1-) Through the assessment of the seismic risk and all its affecting factors (hazard, exposure and vulnerability) to compare the results of the assessment with the results obtained based on the preliminary assessments carried out after the earthquake of 26 November and presented in the PDNA document; 2-) To establish a procedure which can be used for risk assessment on a similar scale for other municipalities/districts of the country. This paper will not only highlight the strong and weak points for the territory of Durrës, but will give useful instructions in using the proposed methodology in other territories, without waiting for the next seismic event with possible damaging consequences.","PeriodicalId":427395,"journal":{"name":"2nd Croatian Conference on Earthquake Engineering ‒ 2CroCEE","volume":"192 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129018353","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"POSSIBLITIES OF USING UHPC AS A REPAIR MATERIAL","authors":"Antonija Ocelić, A. Baričević, Marina Frančić Smrkić","doi":"10.5592/co/2crocee.2023.111","DOIUrl":"https://doi.org/10.5592/co/2crocee.2023.111","url":null,"abstract":"More and more buildings need to be repaired and strengthened, both for durability and for the effects of natural disasters such as earthquakes. The repair material should ensure compatibility with the substructure materials and contribute to their improvement. The continuous development of materials has led to their excellent properties and application possibilities. In addition, the new generation of materials offers more environmentally friendly solutions, which is certainly in line with repair as part of sustainable development. In an effort to meet all these requirements, the use of mortars with exceptional properties and environmental efficiency can be the key to solving repair works. Materials such as ultra-high performance concrete (UHPC) are characterised by exceptional mechanical and durability properties. In its usual composition, it contains large amounts of cement, which can be reduced by using waste materials to improve its environmental performance. One of the properties of UHPC worth highlighting is its toughness, which is achieved through the use of fibres that ensure a cement composite with ductile behaviour. Therefore, this paper presents a general overview of UHPC and the possibility of its application as a repair material. The evaluation of UHPC as a repair material is based on the studies carried out. These are divided into tests of interfacial properties, which include bond strength, microstructure, and permeability. The influence of additional cementitious materials on the interfacial microstructure is presented. Finally, the importance of fibres and the potential self-healing effect of UHPC in repair are highlighted and opportunities for new studies are identified.","PeriodicalId":427395,"journal":{"name":"2nd Croatian Conference on Earthquake Engineering ‒ 2CroCEE","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129652495","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"ANALYTICAL SEISMIC FRAGILITY CURVES FOR ANCIENT MASONRY BUILDINGS IN PORTUGAL","authors":"V. Bernardo, A. C. Costa, P. Candeias, A. Costa, P. Lourenço","doi":"10.5592/co/2crocee.2023.127","DOIUrl":"https://doi.org/10.5592/co/2crocee.2023.127","url":null,"abstract":"The seismic performance of buildings has received special attention due to the interest in the built heritage conservation and protection of human life. The historic urban centers are dominated by old unreinforced masonry (URM) buildings, which techniques and construction materials have evolved during centuries. Given the presence of these buildings in areas of significant seismicity, extensive research is needed to assess the seismic risk and define mitigation policies. This kind of studies is often supported by empirical methods and based on expert judgment due to the high variability of the building stock and lack of information. The main purpose of this work is to provide analytical fragility curves for representative masonry buildings in Portugal, built before the introduction of the first design code for building safety against earthquakes (RSSCS) in 1958. Thus, the fragility curves derived can characterize the capacity of the Portuguese building stock considering the randomness in the material properties and the variability in the geometry.","PeriodicalId":427395,"journal":{"name":"2nd Croatian Conference on Earthquake Engineering ‒ 2CroCEE","volume":"63 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124168137","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}