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The necessity of joining structural and architectural approaches to reach human- oriented structures and develop contemporary urban environment is presented through several examples. Projects of an airport, a stadium and few bridges as outcomes of collaboration between structural engineers and architects will be overviewed.

U radu je dan pregled mehanizama razaranja i oštećenja zidanih svođenih mostova, metoda ispitivanja za utvrđivanje svojstava postojećih konstrukcija te konzervativnih i sofisticiranih metoda ocjenjivanja. Na temelju analiza svođenih mostova malih raspona provedenih trima konzervativnim metodama ocjenjivanja i dodatnih razmatranja učinaka pojačavanja i prilagodbe ovih mostova u njihovom vijeku trajanja suvremenim prometnim zahtjevima, razvijena je izvorna procedura preliminarnog ocjenjivanja koja sadržava tri osnovna koraka: prikupljanje podataka, ocjenjivanje svoda i ocjenjivanje kolničke ploče.

The assessment of a masonry arch bridge, built more than 110 years ago and widened twice with concrete decks during it service life, is presented in this paper. Conservative methods for the assessment of the load-carrying capacity of masonry arch bridges are shortly overviewed. Additionally the bridge deck cantilever is evaluated due to the bad condition of the second widening deck, taking into account the possibility of vehicle impact on the guardrail. Results are discussed and the deck cantilever replacement with the adequate new reinforcement is proposed.

In this paper successful collaboration between structural engineers and architects is highlighted on the examples of designs of a bridge, an airport and a sport stadium. The designing team comprising structural engineers and architects successfully developed a type of structure which was then repeated, modified and implemented in all three designs. The designs were submitted in open design competitions in 2008 and 2009. The bridge and the airport designs won the first prizes.

In this paper an assessment of the bearing capacity and the evaluation procedure of the condition of the driving deck of an three span masonry arch bridge are shown utilizing the simplest conservative methods.

Prof. dr. sc. Čandrlić je jedan od dugovječnih građevinskih stručnjakau Hrvatskoj, čiji bogati znanstveni opus po svojem značenju prelazi granice Lijepe NAše. U nekim djelima predstavlja izvorne domete, koji su postali općeprihvaćeni u graditeljskoj praksi. Kao istaknuti predstavnik primijenjene znanosti, vlastita iskustva je stjecao neoposredno u projektnim biroima i na gradilištima ; potom je iz stvarno uočenih i neriješivih problema sticao inspiraciju i podlogu za znanstveni rad, kako bi analizirane spoznaje nadalje primjenjivao u praksi.

Croatian Standards for Concrete Structures are implemented European prestandards since 2006, for Masonry Structures Croatian Standards are mandatory since 2007, and the Codes for Timber (2008) and Steel (2009) Structures prescribe the utilization of future Croatian Standards (EN with National Annexes) effective immediately upon their issue. In order to facilitate and simplify the transition to New Codes and Standards a programme of education and training for Civil Engineers is obligatory since 2005. The National implementation of Eurocodes is encouraged by organizing Conferences, Courses and Workshops on topics of interest for Civil Engineers. At these events discussions are encouraged about issues, challenges and ways of application of new norms. Lectures are given by scientists, faculty teachers, civil engineers, architects and government officials. The implementation of Structural Eurocodes in Croatian Engineering practice and the programme of education and training of Civil Engineers will be shortly presented in this paper.

In this paper the procedure for establishing the funicular shape of a polygonal (deck-stiffened, inverted Langer) arch will be discussed. In this type of structure the deck is resisting any tendency to bend or buckle. So the deck is thicker than the arch which carries only pure compression. The funicular shape of an arch coincides with its line of trust which is the set of resultants of the trust and weight each part of an arch imposes on the next lower one. In this way all sections along the axis of the arch are in direct stress and the material required to construct the arch is minimized. For a particular set of loads the arch profile in direct stress is called the funicular arch. The procedure starts with imagining that the loads carried by the arch are applied to a cable. Usually this shape is determined for the dead load. The designer can automatically generate a funicular shape for the loads. If the cable shape is turned upside down, the result is a funicular arch. This type of structure was developed by the Swiss engineer Robert Maillart.

U radu je dan prikaz udžbenika za predmet "Trajnost konstrukcija na diplomskom studiju Građevinskog fakulteta Sveučilišta u Zagrebu.

U predavanju je dan pregled stečenih iskustava Hrvatskog društva građevinskih konstruktora kroz petogodišnje razdoblje programa stručnog usavršavanja osoba koje obavljaju poslove graditeljstva s osvrtom na odgovarajuće odredbe Pravilnika.

Autori uvodno ističu činjenicu da veliki broj parametara utječe na oblikovanje ovješenog mosta. U ovome radu pojašnjeni su osnovni zahtjevi za oblikovanje grede, zatega i pilona. Ovakva podjela nužna je radi preglednosti, ali u proračunu valja voditi računa o izraženom međudjelovanju osnovnih nosivih konstrukcijskih elemenata. Nadalje u radu su osnovne karakteristike mosta Jarun objašnjene u sklopu smjernica za oblikovanje ovješenih mostova uz pojašnjenje njegovih posebitosti.

A new concrete arch bridge with 204.0 m span was constructed across the Krka River canyon on the section Skradin-Šibenik of the Adriatic highway. The bridge site lies in an environmentally protected area very close to the Krka national park. The superstructure is continuous with spans L=3x32.0+3x28.0+3x32.0+28.0+24.0=360.0 m. The application of the composite superstructure, made possible significant reduction of the dead weight and enhanced the bridge appearance in comparison to other Croatian concrete arch bridges. The construction of the bridge across the Krka River canyon commenced in the year 2003 and was successfully completed in two years in the year 2005. The whole arch cross section was constructed by free cantilevering, on traveling formwork carriages, in segments 5.25 meters long, starting symmetrically from arch abutments. Double columns at the arch abutments had to be extended by auxiliary steel staying pylons to facilitate successive cantilevering. The arch was supported during construction by stays equilibrated by anchor stays, connected to rock anchors. The steel superstructure grillage was erected by longitudinal launching in three phases. The concrete deck plate constists of from full depth precast slabs interconnected by on site concreting of longitudinal and transversal joints above shear connectors. A detailed review of the Krka Bridge construction is elaborated upon in the paper.

U radu se prikazuje projekt mosta Bundek u Zagrebu koji je izrađen na temelju natječajnog rada koji je dobio prvu nagradu. Prostorna čelična konstrukcija kakva je primijenjena za most Bundek novo je i originalno rješenje. U ovome radu opisane su osnovne tehničke karakteristike mosta i tijek stvaranja nosivog sustava kao arhitektonske vizije izgleda grada Zagreba. Pojašnjen je urbani dizajn budućeg mosta i poboljšanje prometne komunikacije između obala Save i postojećih mostova.

U radu su prikazani rezultati analize tipskih detalja cestovnih mostova koju kontinuirano provodi Katedra za mostove Građevinskog fakulteta Sveučilišta u Zagrebu. Analiza se temelji na usporedbi dobrih i manje dobrih rješenja na izvedenim građevinama, stanju u nama bliskim zemljama kao i zemljama EU-a, primjeni suvremenih propisa i nastojanju za postizanjem što trajnijih građevina. Preporučeni su detalji koji zadovoljavaju sve kriterije o održavanju, trajnosti i troškovima.

Na jugozapadnom ulazu u grad preko Save se predviđa izgraditi most koji će povezati južni ulaz i zapadni dio grada. Grad Zagreb – Gradsko poglavarstvo i Hrvatsko društvo građevinskih konstruktora proveli su javni natječaj za idejno rješenje mosta Jarun na koji je pristiglo deset rješenja. U ovom radu prikazana su sva pristigla rješenja s naglaskom na ovješeni most s kosim pilonom kojem je dodijeljena prva nagrada.

The disadvantage of the whole system of initiation of European standards is the transition period with the parallel application of old standards and new codes. Today it is legally possible to use Croatian standards as implemented European pre-standards for concrete structures, for masonry structures Croatian standards are mandatory, and the code for timber structures prescribes the utilization of future Croatian standards (EN with National Annexes), expected to be issued sometime during 2010. The code for steel structures is not issued yet. The Structural Engineering Conferences programme of education and training of civil engineers in order to facilitate the transition to new codes and standards is shortly presented in the paper. We firmly believe that EN norms with adequate National Annexes have to be implemented in Croatia, as soon as possible, as substantiated by our analyses and performed comparisons.

Young engineers live in a permanent state of now and today without any connection to the past, which is missing even in their lifetime. This makes the historians and their task to remember what others have forgotten even more important. In this overview development of concrete as a material and contribution of the concrete application history in development of bridges, with the emphasis on arch bridges is shown. Some examples of concrete and steel combinations in order to employ the best properties of each material show the possibilities for new types of arch bridges. Biographies of famous engineers, designers and builders with their most important achievements are shortly presented. Accomplishments of Bridge Chair of the Zagreb Faculty of Civil Engineering in the development of concrete application and concrete bridge structures design procedures trough the educational, scientific and professional work are elaborated.

Two new bridges across the Sava River in the city of Zagreb are to be built to link the south and north part of the city. The City Council of Zagreb and the Croatian Society of Structural Engineers organized public competitions for the preliminary bridge designs for two bridges. For both bridges eighteen (18) proposals were entered by different design teams, comprising both bridge engineers and architects. In this paper all eighteen proposals are shown including beam type bridges, through and half trough arch bridges, cable-stayed bridges, made of concrete or steel or of composite type. The two first prize winners are shown in some detail.

Two new bridges across the Sava River in the city of Zagreb are to be built to link the south and north part of the city. The City Council of Zagreb and the Croatian Society of Structural Engineers organized public competitions for the preliminary bridge designs for these two bridges. For both bridges eighteen (18) proposals were entered by different design teams, comprising both bridge engineers and architects. In this paper the two winning solutions are shown in some detail.

The Old Bridge in Mostar ranks among the greatest historical monuments on the Balkans. The bridge was demolished in 1993 during military operations in Mostar. According to the records kept in the Sarajevo National Museum, the construction of the Old Bridge started in 1557 and was completed nine years later. After the war the bridge was rebuilt. In this paper some of the most interesting stages in recon-struction are shown.

Magistarski rad obrađuje temu mostova bez reški i ležaja. Ugradnja ležaja i prijelaznih naprava povećava troškove gradnje, na mjestu unosa sile dolazi do nepovoljnih koncentracija naprezanja, ali što je važnije povećavaju se troškovi održavanja. U radu je dan sustavan pregled mogućnosti projektiranja i izvedbe mostova bez reški i ležaja s razrađenim podlogama i pomagalima za oblikovanje i proračun. Ovaj rad sastavni je dio istraživanja Katedre za mostove kojima se nastoji poboljšati ukupnu kvalitetu mostovskih konstrukcija. Postupak gradnje bez reški i ležaja uspješan je i u svijetu često primjenjivan postupak gradnje jer uz definiranu kvalitetu građevine i umjerene troškove gradnje osigurava najmanje troškove održavanja. Za očekivati je da će se mostovi bez reški i ležaja pojačano početi primjenjivati u Hrvatskoj, a ovaj rad omogućuje uvid u problematiku tog sustava.

Principles of structural art in bridge design are explained in this paper. Significant Croatian arch bridges from Roman times to contemporary structures are described. Their constructional, functional, economical and aesthetic features – their characteristic raising them to the level of art are contemplated. Designers of these bridges, brought into designs their great engineering knowledge on safety, serviceability and durability but also their own creativity, originality, sensibility, and intuitive judgement.

There are six major reinforced concrete arch bridges in Croatia located on Adriatic coastline. An important issue in developing maintenance strategy for Adriatic arch Bridges is determining of the structure with respect to increase in loading as well as changes in the requirements of relevant codes and standards over the decades of bridge service. The reliability analysis is necessary to determine the safety margin of existing bridge structures and their capacity to sustain present loads and fulfil all requirements of the new European standards. In this paper some relevant comparisons indicating the influence of Eurocode requirements on Adriatic arch bridges are shown. Additional measurement, inspections and analysis are carried out to prosecute with steps of the reliability analysis procedure.

A new bridge across the Sava River in the city of Zagreb is to be built to link the south entrance into the city with the west of the city. The City Council of Zagreb and the Croatian Society of Structural Engineers organized a public competition for the preliminary bridge design. Ten alternative proposals were entered by different design teams, comprising both bridge engineers and architects. In this paper all ten bridge proposals are shown with particular emphasis on the cable-stayed bridge, which was awarded the first prize.

A new bridge across the Sava River in the city of Zagreb is to be built to link the south entrance into the city with the west of the city. The City Council of Zagreb and the Croatian Society of Structural Engineers organized a public competition for the preliminary bridge design. Ten alternative proposals were entered by different design teams, comprising both bridge engineers and architects. In this paper all ten bridge proposals including beam type bridges, through and half through arch bridges and cable-stayed bridges, made of concrete or steel or of composite type are shown. Particular emphasis is given on the asymmetrical cable-stayed concrete bridge, which was awarded the first prize. The main span is 150 m with the overall bridge length of 625 m. The superstructure is a continuous box type prestressed girder with constant depth of 280 cm over eleven spans. The inclined concrete box-type pylon is 88 m high of which 75 m are above the superstructure.

In this paper some construction project management issues of large concrete arch bridges will be discussed. There are six major reinforced concrete arch bridges located along Croatian coastline with spans ranging from 200 m to almost 400 m: Šibenik, Pag, Krk (two arches), Maslenica and Skradin bridges. The task of the designer is to propose and enforce appropriate reliable structural solutions that not only ful-fill the statical requirements but are also durable for any adopted construction technology. The choice of ade-quate details is of utmost importance in attaining required durability with minimum maintenance. For two arch bridges, the Maslenica bridge (200 m) built 1997 and Skradin bridge (204 m) built 2004 com-parisons in terms of construction project management are given. For the Skradin bridge some improvements which enabled ease of construction were implemented.

The recent construction of over 700 km of new Croatian Highways and roads emphasized the need to standardize the bridge detailing, especially for short and medium span bridges. Due to topographic conditions a large number of short and medium span bridges greatly influence the cost and erection time. The main goal for this standardization of bridge detailing beside the buildability, durability, maintainability and traffic safety is the creation of a bridge design concept that allows innovative design and systems for highway bridges. The standardization project combines the theoretical knowledge and experience of designers, constructors and road authorities. The project is divided into parts that can be further developed and changed according to the latest practice. In this paper a short overview of the standardization of bridge detailing project is given. Also some typical experience in choosing details for bridges in maritime environment is discussed.

New Croatian standard, implementing European pre-standards with national spacifications incorporated in National Application Documents, have become mandatory for reinforced and prestressed concrete structures. Durability aspects in new Croatian standards are explained. The significance of durability issues interrelation through the project stages is emphasised. The improvement of bridge structures projects to provide increased durability is presented in this paper.

U radu je dana recenzija knjige ˝Betonske konstrukcije - Priručnik˝

Dovršena je izvedba mosta preko kanjona rijeke Krke na Jadranskoj autocesti, dionica Skradin-Šibenik. Izgradnjom mosta preko Krke nastavljena je tradicija gradnje velikih betonskih lučnih mostova u Hrvatskoj. Ovaj most je ipak jedinstven među hrvatskim armirano betonskim lučnim mostovima jer je rasponski sklop projektiran u spregnutoj izvedbi, čime je postignuto bitno smanjenje stalnih djelovanja i ostvaren izvrstan estetski dojam. U radu se daje sažeti opis novog mosta s prikazom konstruktivnih izmjera složenog nosivog sklopa koji čine armirano betonski luk, armirano betonski stupovi i spregnuti rasponski sklop.

Procesi koje se odvijaju u betonu pri građenju betonskih konstrukcija, a počinju već proizvodnjom betona i neposredno nakon toga hidratacijom cementa i očvršćivanjem cementnog morta tijekom transporta, ugradnje i njege u konstrukcijskom elementu vrlo su složeni i međusobno ovisni. U kontroli i potvrđivanju sukladnosti kvalitete naglasak je na početnim ispitivanjima i utvrđivanju zahtjevanih svojstava, a kasnije i u proizvodnji i u primjeni na što preciznijim postupcima u pojedinim fazama i procesima i nadzoru nad njihovim poštivanjem, prilagođenim vrsti i značaju pojedinih konstrukcija i tehnologiji njihove izvedbe. Ovaj dio priručnika prati beton od specifikacija okoliša u kojem se rabi i svojstavaoja će to zadovoljiti, preko proizvodnje i transporta, do ugradnje i zaštite u izvedenom dijelu konstrukcije, uz preciziranje svih mjera i postupaka kontrole i osiguravanja kvalitete.

Dovršena je izvedba mosta preko kanjona rijeke Krke na Jadranskoj autocesti, dionica Skradin-Šibenik. U radu se daje opis izgradnje novog mosta složenog nosivog sklopa koji čine armirano betonski luk, armirano betonski stupovi i spregnuti rasponski sklop.

Statički proračun mosta preko kanjona rijeke Krke na Jadranskoj autocesti, dionica Skradin-Šibenik proveden je u skladu sa suvremenim saznanjima i propisima mostogradnje. U radu se daje sažeti prikaz statičkog i dinamičkog proračuna temeljem kojeg su odabrane i provjerene sve konstruktivne izmjere složenog nosivog sklopa koji čine armirano betonski luk, armirano betonski stupovi i spregnuti rasponski sklop.

U radu su dani osnovni podaci o kabelima i trakama za prednapinjanje od spregnutih gradiva. Navedena su svojstva takvih kabela i njihove prednosti i nedostaci u odnosu na čelične kabele. Za tri tipa kabela, od staklenih vlakana (GFRP), aramidnih vlakana (AFRP) i ugljičnih vlakana (CFRP), navedeni su primjeri izvedenih građevina sa posebnim osvrtom na tehnologije i vrste proizvoda od ugljičnih vlakana. Ukazano je na problem sidrenja koji bi omogućio ravnomjerniji unos sile prednapinjanja

With its dimensions and significance the Mainland – Pelješac bridge will be the major and the most complex building project in Croatia. In this paper, alternative bridge designs, made by the Department for Structural Engineering of the Faculty of Civil Engineering in Zagreb and by the Institute of Civil Engineering are presented. Alternative bridge designs are continuous steel superstructures with spans up to 200 m, the continuous steel box on the V-shaped piers with span lengths of 242 m, the sequence of arches with spans of 290 m, the main cable stayed bridge 330 m in span with 170 m long approach spans and the main tied arch bridge 350 m in span with 200 m long approach spans. The design and the predicted cost of bridge alternatives are presented.

U radu su izvojena najvažnija pravila armiranja koja mogu poslužiti pri projektiranju. Korištena su pravila određena hrvatskim normama na koje se poziva Tehnički propis za betonske konstrukcije, ali su načinjene usporedbe sa Njemačkim normama.

U ovome radu razmatranju se pretpostavljena djelovanja sila prisila prema tehničkim propisima koja pojednostavljuju stvarne odnose. Naprezanja od prisile ne moraju se u svim slučajevima jednako točno proračunati. Potrebna je svijest projektanta o prisilama kako bi ih uzeo u obzir konstruktivnim rješenjima.

Nove norme i propisi donose značajne promjene. Prvenstveno se to odnosi na nove pojmove, definiranje klasa utjecaja okoliša (izloženosti), postupak opisivanja i određivanja sastava betona, kao i jednoznačno određivanje područja odgovornosti. Iz njemačkih iskustava vidljivo je da su potrebne značajne predradnje kako bi se novi propisi i norme mogle primjenjivati u obrazovanju studenata i praksi.

The calculation procedure of longitudinal movements for selection of expansion joints is presented in the paper. Proposals for thermal actions, the correction factor for movements due to creep and shrinkage and equations for design movements are given.

Ulaskom u Europsku Uniju naši projektanti moraju biti spremni prihvatiti europske norme, naravno uz prethodnu analizu i uzimanje u obzir osobitosti našeg područja. U ovom radu prikazana su neka osnovna i važna pravila u rješavanju detalja armature, prvenstveno pravila sidrenja i nastavljanja nenapete armature te pravila pri odabiru velikih profila armaturnih šipki.

A short overview of several recently built Croatian bridges is presented, designed for improved durability. All depicted bridges have been designed by the Structural Department of Civil Engineering Faculty in Zagreb, Croatia.

Osnovni kriterij dobrog vođenja kabela je jasno prepoznavanje odstupanja predviđenih vrijednosti od stvarno izmjerenih. Kada je koeficijent trenja značajno veći od računski predviđenog to treba dovesti i do značajnijih promjena izmjerene duljine izduljenja kabela. Stoga je izuzetno važno kod prednapetih konstrukcija primjeniti sva potrebna pravila oblikovanja.

U radu su prikazane osnovne značajke standardnih mostova prema projektima hrvatskih projektanata. Dan je i kratak opis mostova koji su nešto većih raspona.

Kod željezničkih mostova prisutna je znatno manja različitost stvarnih prometnih djelovanja nego je to slučaj za cestovne mostove. Ovdje se uspoređuju trenutno važeći hrvatski propisi, njemački propisi DS-804 i europski propisi koji bi se trebali koristiti u skoroj budućnosti i ističu razlike u određivanju dinamičkih faktora, računskih djelovanja i ograničenja progiba.

Opisan je postupak uzdužnog potiskivanja. Riječ je o jednom od suvremenih postupaka građenja grednih mostova koji je odnedavno zaživio i u Hrvatskoj. Navedeni su potrebni preduvjeti primjene postupka. Dane su preporuke za projektiranje i izvedbu te navedeni primjeri primjene u Hrvatskoj.

U radu su prikazani neki problemi proračuna mostova, ilustriranih s nekoliko primjera uporabe računala u smislu stvaranja posebnih programa za određene namjene. Primjeri su vezani za različite tehnologije izvedbe (gredni, lučni i ovješeni mostovi), i obuhvaćaju nekoliko većih mostova projektiranih na Odjelu za konstrukcije na Građevinskom fakultetu Sveučilišta u Zagrebu

U radu je ukratko objašnjen koncept masivnih integralnih mostova. Prikazane su osnovne prednosti i mane takve konstrukcije u odnosu na konvencionalne mostove.

Dionica Kupjak-Vrbovsko autoceste Zagreb-Rijeka u km 64+878 prelazi preko kanjona Kamačnik na približno 60m visine. Predviđen je asimetričan prednapeti rasponski sklop, kontinuiran preko tri polja. Izvedba konzolnim postupkom moguća je izvedbom pomoćnog stupa te protutereta na kraju najkraćeg polja.

Uspoređene su vrijednosti sile kočenja vozila prema trenutno važećim hrvatskim propisima te prema njemačkim propisima DIN-1072. Naglašava se da bi preuzimanje prometnih opterećenja iz njemačkih propisa, trebalo rezultirati preuzimanjem ovih propisa u cijelosti, odnosno proračun sile kočenja provesti prema istim propisima. Veličina sile kočenja značajna je kod proračuna većih duljina dilatacijskih cjelina uz veću visinu mosta nad terenom.