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In this study, the city of Osijek is used as a case study area for low to medium seismicity regions with deep soil over deep geological deposits to determine horizontal PGA values. For this reason, we propose new regional attenuation equations for PGA that can simultaneously capture the effects of deep geology and local soil conditions. A micro- zoning map for the city of Osijek is constructed using the derived empirical scaling equations and compared to all prior seismic hazard estimates for the same area. The findings suggest that the deep soil atop deep geological sediments results in PGA values that are only 6 percent larger than those reported at rock soil sites atop geological rocks. Given the rarity of ground motion records for deep soils atop deep geological layers around the world, we believe this case study is a start toward defining more reliable PGA estimates for similar areas.

Earthquakes are considered one of the strongest and most destructive natural forces since its consequences, in addition to material damage and damage to buildings, are human suffering, large economic losses and costs related to the care of the population after the earthquake. The two earthquakes that struck the Republic of Croatia two years ago demonstrated this. In order to reduce earthquake risk, this paper presents an earthquake risk assessment methodology based on the hybrid seismic vulnerability method. The hybrid seismic vulnerability method is based on the calculation of the Damage Index, i.e., the structural damage of the building. The building is represented by a single degree of freedom model. The described methodology was applied in an area of the city Osijek in the eastern part of the Republic of Croatia.

Data on social and economic losses from earthquakes so far show that the most frequent and greatest losses are those caused by damage and collapse of buildings. Assessment of earthquake hazard, analysis of exposed physical and social values, and estimation of seismic vulnerability are all parts of the earthquake risk assessment process. In addition to the model of possible earthquake hazards, the basis for risk assessment for an observed area is the existence of an exposure model. Rural settlements are an important part of the cultural heritage because of their natural, historical and traditional values. Usually, there are significant differences in buildings built in rural areas, depending on preferred or locally available building materials, climatic conditions, traditions, as well as owners' income levels and social habits. In different regions of Croatia, there is also a variety of rural housing types. In Slavonia and Baranya, the process of gathering settlements and stabilizing the population began after the liberation from the Turks in the mid-18th century. Villages are grouped around earlier settlements along existing or newly built roads. Planned settlements are created with several streets properly arranged in relation to the main road. The villages of Eastern Croatia (Slavonia and Baranya) are areas of traditional construction of residential and farm buildings. Even today, in some villages, there are old houses built of stuffed clay masonry (clay mixed with water and as a conglomerate, then poured into wooden modulus and stuffed) ; wooden framing masonry (a wooden frame and stuffed clay or unbaked bricks), or adobe. Since the mid-19th century houses were built of unbaked and later baked bricks, but today, due to seismic regulations, the most common type is confined masonry. The paper will attempt to present an exposure model for small rural areas in eastern Croatia. The exposure model shows structural characteristics, which include information of lateral load resistance system, materials, number of stories, average built area, and population. The location and distribution of buildings are presented using the Geographic information system. The classification of building stock is made according to a set of building classes that indicate the structural characteristics and expected performance under seismic action. A brief overview of existing classifications is conducted as well in order to identify predominant building classes. Thus, based on all the available information, the seismic vulnerability of the buildings is assessed for a given level of seismic hazard. Using one of the common vulnerability methods, the obtained results in terms of the expected degree of damage are presented using a Geographic information system.

The article evaluates the damage assessment of a plane reinforced-concrete frame structure with the application of a nonlinear incremental dynamic analysis (IDA) on a numerical model of the building. Behavior assessment and fragility is based on a plane model obtained by analyzing the real frame structure. The nonlinear analysis is repeated for each incremental increase of earthquake intensities. For the estimation of structure vulnerability due to earthquake motion, the incremental dynamic analysis was applied on the numerical model of the building - a plane reinforced concrete frame. The fragility curves, constructed from IDA results, represent a very useful probabilistic tool for estimating earthquake behavior.

Iako su novije zgrade projektirane u skladu s propisanim zahtjevima norme HRN EN 1998-1:2011 za proračun potresno otpornih zgrada, još uvijek postoji značajan broj starijih zgrada koje su izgrađene ne slijedeći ikakve norme. Studija provedena u radu zasniva se na procjeni potresne oštetljivosti zgrade osnovne škole u Osijeku projektirane 70-tih godina prošlog stoljeća, čiji je nosivi sustav armiranobetonski okvir. Za procjenu potresne oštetljivosti primijenjen je dinamički proračun korak po korak na numeričkom modelu zgrade – ravninskom armiranobetonskom okviru niske duktilnosti.

Pristup novim tehnikama ojačanja mora se pristupiti s oprezom s obzirom na neusklađenost vremena i resursa potrebnih za provođenje ispitivanja te validaciju rezultata. U nekim slučajevima dolazi do prebrze primjene novim materijala i tehnika, bez izrađenih pravila za projektovanje, proračun, pa čak i sam način izvedbe, te spoznaje o kratkoročnim i dugoročnim uticajima na učinkovitost primjenjene tehnike. Rezultati dobiveni od preliminarnih ispitivanja tekstila od bazalta bili su polazna tačna za početak primjene ovog materijala pri ojačanju kulturno-historijskih objekata kod kojih je upotreba epokisdnih smola zabranjena.

Potresni rizik raste s urbanizacijom širom svijeta te postaje značajan problem za države u razvoju. Sukladno tome, procjena potresnih rizika mora se izvršiti za urbana područja izložena riziku, kako bi se smanjila oštetljivost nakon mogućih katastrofalnih potresa. Primjenom simulacijskih modela koji procjenjuju baze podataka o zgradama i gustoćama naseljenosti urbanih područja, ispitani su faktori rizika i definirani mogući potresni rizici. Kao rezultat, predložen je model predviđanja s indikativnim ishodom za ugrožene zgrade i stanovništvo u urbanim područjima u funkciji vršnog ubrzanja temeljnog tla. Rezultati analize su ukazali na potrebu za nužnim detaljnim pristupom riziku za ugrožene gradove i na nužno upozorenje gradskim upravama da se direktno uključe u analizu potresnih rizika prije katastrofa i planiranja kako bi potaknuli razvoj strategije smanjenja rizika.

The buildings of architectural and cultural heritage are mostly built with stone or brick wall elements, which are connected using limestone or limestone cement mortar, without a full knowledge of the mechanical properties of masonry structures. The compatibility of heritage masonry buildings with valid technical specifications and the rules for earthquake resistance implies the need for construction work such as repairs, strengthening or reconstruction. By strengthening the masonry buildings, ductility and bearing capacity are increased to a level, which, in the case of the earthquake design, allows for some damage to happen, however the structure retains sufficient usability and bearing capacity without the possibility of collapse. Comparison between traditional and modern techniques for seismic strengthening of masonry buildings is given according to their effects, benefits and disadvantages. Recent Croatian provisions provided for heritage buildings enabling deviation of technical specifications are discussed.

Glavni postupak za procjenu potresnog rizika je analiza potresne oštetljivosti koja daje uvid u postignutu mjeru sigurnosti konstrukcijskih sistema. Na osnovu procjene potresne oštetljivosti zgrada proračunava se gubitak nosivosti i upotrebljivosti, ekonomski gubici i izloženost ljudi povređivanju i pogibiji tokom potresa. U osnovi svake analitičke metode, koje se sve više primjenjuju u procjeni seizmičke oštetljivosti te procjeni gubitaka, je definisanje odnosa intenzitet potresa- oštećenje, odnosno predviđanje konstrukcijskog odgovora na pobudu datog intenziteta. Upotrebom analitičke metode zasnovane na spektru sposobnosti nosivosti procijenjena je seizmička oštetljivosti šezdesetak secesijskih zidanih zgrada grada Osijeka, odabranih iz baze zgrada grada.

Izgradnja mostova predviđa velika investicijska ulaganja, a sami mostovi predstavljaju „žilu kucavicu“ cestovne i željezničke infrastrukture. Procjena stanja mostovske konstrukcije predstavlja značajni element vezan prvenstveno za osiguranje sigurnosti objekta. Izreka „bolje spriječiti nego liječiti“ se definitivno može primijeniti kod mostova s obzirom na to, da neadekvatno održavanje može dovesti do nagle deterioracije konstrukcije, što može dovesti do značajnih posljedica i na kraju do njene neuporabljivosti. U Bosni i Hercegovini održavanje mostova na cestovnoj mreži podijeljeno je na entitetske ovlasti. U Federaciji Bosne i Hercegovine na federalnoj razini se održavaju magistralne ceste, na kantonalnoj razini regionalne i na općinskoj razini lokalne ceste. U radu će biti prikazani podatci vezani za mostove koji se nalaze na magistralnim cestama. Analizirat će se period uporabljivosti konstrukcije od izgradnje do rušenja, te način upravljanja objektom.

Nastankom potresa ne dolazi do utjecaja na život jednoga čovjeka ili manje skupine ljudi, već su najčešće pogođena čitava urbana i ruralna središta. Potres ne donosi samo štete na građevinama i infrastrukturi, već za sobom nosi i ljudske žrtve te narušavanje ekonomske i financijske slike država. Utvrđivanje potresnog rizika za neko područje (ili posebnu zgradu, ili sustav infrastrukture) predstavlja analitičku metodu koja integrira informacije, baze podataka i karte koje prikazuju opće karakteristike opasnosti te okoline, s bazama podataka o općim karakteristika i oštetljivosti izgrađene sredine. Oštetljivost je definirana kao stupanj gubitka danog elementa rizika koji je posljedica dane razine opasnosti. S obzirom na do sada zabilježenu potresnu aktivnost na području Republike Hrvatske, iznimno je važno sustavno bilježenje podataka o zgradama te opis njihove tipologije kako bi se definirala izloženost specifičnim opasnostima. Ovi podatci se upotrebljavaju za proračun mogućih gubitaka.

U radu je prikazan plan kvalitete izvođenja čelične konstrukcije za različite klase izvođenja prema HRN EN 1090-2. Za odabranu konstrukciju prikazan je plan montaže koji obuhvaća uvjete na gradilištu, metode montaže, mjerenje i praćenje procesa montaže, pripremu oslonaca, sidara i ležajeva te opis procesa montaže i rada na gradilištu.