Grand Opening of Pelješac Bridge

 The Pelješac Bridge is a part of the national road which goes around the Neum Corridor. It is a part of the project called "Road Connection with Southern Dalmatia". The project includes the construction of the bridge, access roads to the bridge as well as the Ston bypass, which has enabled the establishment of a strong road connection between the separated parts of the land territory of the Republic of Croatia. The 32.5 kilometers long two-lane state road connects the far south and is an essential prerequisite for the development of the mainland and islands of the Dubrovnik area. The 2404 meters long Pelješac Bridge is the most challenging part of the project and it crosses a sea strait – the Mali Ston Channel. The project "Road Connection with Southern Dalmatia" is a strategic interest of the Republic of Croatia. It is also located on one of the European transport corridors, therefore it has been largely financed from EU funds.

The width of the sea channel at the bridge site is 2140 meters, and the average sea depth is 27 meters. A waterway passes through the bay, which is protected as a special nature reserve: the designated navigation passage is 200 meters wide and 55 meters tall. The foundation soil, which consists of deep silt and clay deposits above a rock layer, was a challenge to the designers, as were the seismicity of the location and a significant likelihood of strong winds. The task of bridging the sea channel in such complex circumstances was achieved through a unique construction consisting of a suspension bridge with six pylons and five main openings measuring 285 meters each, on deep foundations built on driven piles.

There is a total of 13 openings with start and end support on bridge abutments and a total of 12 in-between support elements. The concept of a bridge without a pronounced central span, symmetrical and with no extremely tall pylon verticals, with a series of identical spans over the central part of the channel and with clearly defined, repetitive elements of pillars, girders, and stay cables was adopted. The construction of the bridge started in mid-2018 and ended in early 2022. The investor of the entire project was Hrvatske ceste, a Croatian company for the management, construction, and maintenance of state roads, while the main contractor was the Chinese company China Road and Bridge Corporation, alongside which numerous Croatian companies and individuals worked on the project.

Stamp Issue: 2022.07.26

Europa - Bridges

At the beginning of the 18th century, after the end of the War of the Spanish Succession and the war against the Ottoman Empire, the conditions to revive the economy and trading in the area of Croatia were met creating a need to connect Pannonia with the coastal area by a road through the mountainous area of Gorski kotar. In 1718, the Croatian Parliament approved the proposal to build a road from Karlovac through Novigrad na Dobri, Delnice, and Javornik to the port in Kraljevica. However, the construction started a while later, in 1725, and was fully completed in 1738. The designer and builder of the road named Via Carolina Augusta, today known as Karolinska cesta, was Matija Antun Weiss (1661 – 1738). The road was named after the ruling emperor, Charles IV, who personally traveled the passable section of the route in 1728. The road is around 60 miles or roughly 106 km long and the planned costs were 70,000 forints. In order to cross over certain streams and rivers, several bridges had to be built on the road, typically wooden constructions on stone columns and abutments.

Among the bridges on the River Dobra, the bridge near Novigrad na Dobri especially stands out. It was built using cut stone. The bridge is located in a tame valley of the river not too far from a castle built on a hill at the beginning of the 16th century. It was owned by the Frankopan, Zrinski, and Patačić families. According to some accounts regarding bridge tolls, there was a wooden bridge prior to this one in the same location.

The bridge is 114.5 m long, and 5.8 m wide and it crosses the river with 10 semi-circular arches with a span of 4.9 m. The columns are massive and harmoniously shaped with pronounced extents. The fences are made of stone, 0.5 m wide and 0.6 to 0.75 m high. The bridge grade level is convex with the highest point in the middle of the bridge. In terms of the layout, the bridge is perpendicular to the river flow. It is an interesting fact that, according to some accounts, the owners of the castle and the surrounding properties had to finance the bridge construction even though the road was financed by the Viennese court.

The bridge is a valuable monument to the bridge building skill and it is in relatively good condition considering that it is more than 250 years old and a protected cultural monument.

The bridge on the River Dobra can be reached from an exit on the Zagreb – Rijeka Highway 1 at the Novigrad junction and then by a local road leading to Novigrad na Dobri. 

The Franjo Tuđman Bridge (Croatian: Most dr. Franje Tuđmana) is a cable-stayed bridge carrying the D8 state road at the western approach to Dubrovnik, Croatia across Rijeka Dubrovačka near Port of Gruž. The original bridge design was developed in 1989; however, construction was stopped at the onset of the Croatian War of Independence. Named after the 1st President of Croatia Franjo Tuđman, the bridge has been redesigned by the Structures Department of the University of Zagreb.

The bridge is 518-meter (1,699 ft) long, measured between the abutments. The substructure of the bridge consists of abutments, a pier on the western shore supporting a pretensioned girder, and an anchoring pier on the eastern shore.

The supported structure on the cable-stayed portion of the bridge consists of a composite girder, an A-shaped pylon, and the cable-stays. The overall span of the girder is 324.7 m (1,065 ft). Concrete roadway slab is of the generally constant depth of 25 cm (10 in). A total of 38 cable stays have been executed, comprising 27 to 61 steel wire cables placed in protective polyethylene pipes.

The pylon is 141.5 m (464 ft) tall, measured from the top surface of the foundations. It comprises a box cross-section of varying sizes. An additional box girder is executed just below the suspended structure providing it additional support as well as bracing the pylon legs. The cable stays are anchored to the top of the pylon. A special opening has been executed in one of the pylon legs, next to the sidewalk, providing access to the inside of its cross-section, where there are rungs facilitating climbing to the top of the pylon, where another opening on its top allows replacements of the anchors, should that become necessary.

The western part of the bridge comprises a pretensioned girder of variable depth 3.25 m (10.7 ft) at the abutment, 8.22 m (27.0 ft) at the pier, and 3.2 m (10 ft) at the end of the cantilever.

Construction of the bridge started in October 1998. The construction works were carried out by Walter Bau AG and Konstruktor, Split. Construction was completed in April 2002, and the bridge was officially opened on May 21, 2002. The bridge construction costs were reportedly 252 million Croatian kuna (c. US$31 million) making Franjo Tuđman Bridge the most expensive bridge in Croatia.

Stamp Issue: 2018.05.02

Bridges and viaducts

Third Guards Brigade 'Kune' Bridge

The A5 Highway on the Beli Manastir - Osijek - Svilaj (r. Sava) route, a component of the C5 branch of the European network carrying the following mark: E73, which is located on the west side of the city of Osijek, near Petrijevci, was supposed to bridge the Drava River and its inundation area. So as not to create a barrier to the future expansion of Osijek, as well as to the possibility of building a hydroelectric power plant on the r. Drava, as a result of a process of choosing a crossing project solution, a bridge with a total length of 2,485 (2,507) m and access viaducts was created. What is interesting is that the Drežnik viaduct near Karlovac is the same length as the "Kune" Bridge, so these two objects share the first place in Croatia with regards to their size. By comparison, the Pelješac Bridge is 2,440 m long.

The bridge consists of three parts: a) the Baranja side access road over the inundation (length: 1,074.5 m, 28 + 29 x 35 + 31.5 m), b) the bridge crossing the Drava river (length: 420 m, 100 + 220 + 100 m), and c) the Osijek side access road (length: 990.5 m, 24.5 + 28 + 26 x 35 + 28 m). Both access roads were built as two separate viaducts, one for each direction. They have span structures made of prestressed T-section concrete supports (height: 1.85 m), with six of them in cross-section, and are connected with a 25 cm thick pavement slab, supported with two Φ 1.8 m columns lying over the overhead beams. The foundations are based on drilled pylons (Φ: 1.5 m). The span structures of both access roads are divided into six expansion units. The center of the object is the part that bridges the Drava, which has been designed with a suspended span construction, with spans of 100 m + 220 m + 100 m, and 75 m tall type A pylons. The pylons are made of reinforced concrete, with a 4 x 5 m (at the top: 3.5 x 6 m) section of arms. From pylons on both sides, a row of 10 diagonal tension rods composed of high-quality steel ropes descends and stretches across. The tension rods are protected by ribbed HDPE pipes. The pylon arms are based on two batches of 25 drilled pylons with a 1.5 m diameter. The span construction of this part, which consists of a three-chamber steel box girder with a cross-section of approx. 12 x 2.8 m, and 8.3 m long prominent consoles supported by steel beams, is supported by the tension rods described, which transmit force to the pylons. The tension rods connect to the span structure in the central chamber of the structure. The total width of the span structure in this part (420 m) is 28.6 m.

The authors of the Concept Project are Peter Sesar, Ph.D. (Civil Engineer) and Damir Tkalčić, M. Sc., while the author of the Main Project is Damir Tkalčić, M.Sc. The construction works were performed by a business association consisting of the following companies: Viadukt d.d., Zagreb; Osijek Koteks d.d., Osijek; Konstruktor Inženjering d.d. and Skladgradnja grup d.d., (both from Split), as well as Hidroelektra - Niskogradnja d.d., Zagreb. The labor contract price of the project in 2009 was approx. 950 million HRK. 

Mirna Viaduct

The A9 highway (Istrian Y highway) connects the city of Pula and famous tourist centers on the west coast of Istria via the Plovanija and Kaštel border crossings with Ljubljana and Trieste, and further on with various cities of Western Europe. On the Nova Vas - Višnjan subsection of this 76.8 km long highway, the floodplain of the Mirna River is bridged by a magnificent viaduct (bridge), with a total length of 1,378 m. In addition to the Mirna River, under the viaducts, there are two smaller canals and a road. The object was built on the route of the right carriageway of the highway. The viaduct for the left carriageway will be built within the scope of the complete project of the A9 highway, which will help this highway reach its full profile. Near the viaduct, the Mirna River meets the sea, and the city of Novigrad is located. The valley below the viaduct offers valuable agricultural crops.

The span construction of the viaduct consists of two solid steel walls with tin carriers of constant height (2.75 m) at a distance of 5.50 m. The carriers are connected by steel cross-members and a 25 cm thick reinforced concrete pavement slab. The static system is a continuous carrier stretching over 22 spans, with a total length of 1,353.86 m. The sizes of the spans are as follows: 51.1 + 15 x 66.5 + 70.1 + 2 x 50.1 + 63.1 + 42.6 + 30.6 m.

The total width of the object is 10.10 m, and it consists of two traffic lanes, each 3.5 m wide, and two protective belts, each 1.0 m wide, as well as protective fence areas, each 0.5 m wide. The ground plan of the viaduct follows a curve (R = 4,005 m). The height of its columns ranges from 13.5 to 40.0 m. Its H section is 4.5 x 3.8 (2.5) m wide and made of reinforced B35 concrete. The abutments, as well as the lower columns, are supported by a rock, while the higher columns, due to weak load-bearing soil, are based on steel 61 m long pylons, connected with reinforced concrete, and a 2.0 m thick headboard. When it comes to the quantity of materials used for the construction of the viaduct, it is as follows: B35 concrete –11,190 m3; BSt 500S reinforcing steel - 1,831 tons; structural steel of span construction St 52-3 – 2,720 tons. Investor: BINA-Istra; Designer: Zlatko Šavor, Ph.D., Master of Civil Engineering. Contractor: Bouygues France. Zvonimir Zdenko Šimunjak, Master of Civil Engineering

Stamp Issue: 2023.03.20

Bridges and viaducts

VIADUKT “MODRUŠ 1” ON HIGHWAY A1 (ZAGREB- SPLIT-DUBROVNIK)

Viaduct „Modruš1“ is the first and the longest in the row of three viaducts of the same name at the road section Ogulin- Brinje of the Highway A1 Zagreb-Split- Dubrovnik, at approach to the tunnel Mala Kapela. The object is situated near the settlement and the ruin of the old town of Modruš which once was also the seat of the Modruška County and can be seen from the right side when driving toward Brinje. The viaduct bridges a deep valley at the height up to 50 m from the lowest point of the valley and has a total length of 516 m and a total width of 31.5 m, enabling thus in standard profile the traffic on highway in both driving directions. Due to that many drivers even do not notice that they have crossed over a remarkable road construction building. In order to get an impression of the size of this viaduct one should exit to a parallel state road D23. The construction actually consists of two parallel, almost identical viaducts each serving one driving direction, which are transversally interconnected for the purpose of checking and maintenance. The levelling line of the viaduct is ascending 4.8% toward the tunnel Mala Kapela. The viaduct consists of 13 sections with centre-to-centre distances of the props (pillars): 38+11x40+38m = 516m. Particular construction spans consist of four prestressed ferroconcrete pillars with coffer cross-section, 2.2 m high and 37 m long, interconnected with a roadway slab. Particular span constructions lean on beam heads of pillars, by means of separate bearings.
The lower structure of the viaduct consists of abutments and pillars based on laminated ferroconcrete foundations, in consideration of rocky basic grounds. The foundations of pillars are 10.0x8.0x2.0 m. The abutments with parallel wings are based in the similar way. The pillars of the viaduct are hollow, of outer cross-section of 2.4 x5.4 m and with the wall thickness of 0.3 m. Used materials are ferroconcrete and prestressed concrete.
The project of the viaduct was made by IGH-Institute for Concrete and Masonry Structures, the designers were Gordana Trogrlić-Uzelac, Stjepan Kralj and Dr. Sc. Petar Sesar. It was built by the company Bechtel-Enka with participation of Croatian companies. The viaduct was opened for traffic in 2005 on the occasion of opening of the A1 Zagreb- Split Highway.

BRIDGE “KRKA” ON HIGHWAY A1 (ZAGREB-SPLIT-DUBROVNIK)

The River Krka, a jewel among rivers of the Adriatic drainage area, probably the most beautiful and attractive among them and well known for its waterfalls, was bridged when the A1 Highway was built, at a point few kilometres downstream from the town of Skradin by an impressive arch bridge. The bridge is located between the nods Skradin and Šibenik, and immediately behind it there is a rest area with a restaurant and viewpoint, from where the view of the bridge and the town of Skradin can be enjoyed. Especially attractive is the view at the bridge for yachtsmen heading to Skradin. The total length of the bridge is 391 m, the width is 22.5 m and it rises 66 meters above the sea level. The main span construction of the bridge over the river Krka is a hollow ferroconcrete arch of 204 m, i.e. 4 m bigger than the bridge of Maslenica (200 m). The cross-section of the arch is 3x10m, with the walls of 0.5 m. As much as 2988 m3 of concrete and 747 t of reinforcement have been built into the bridge, which was constructed according to cantilever principle and with cable support. The structure of the bridge above arch is composed of the grid of steel longitudinal and cross beams with cantilever projections and with rim beams. The longitudinal beams are coffered with cross-section of 0.75x1.7 m and a span of 32 i.e. 28 m. On the described grid a ferroconcrete slab of roadway of 25 cm has been laid. The described structure above arch contains 1700 tonnes of steel, 2172 m3 of concrete and 630 tonnes of reinforcement and it leans on the terrain and the arch of the bridge, by means of pillars reaching up to 55 m. The pillars are of hollow cross-section varying from 3.2x2.5 to 1.8x2.2 m in dependence of their height. Each pillar position has two equal pillars.
It should be pointed out that in the construction of this bridge rational technical solutions have been applied which have made possible – by respecting all prescribed conditions - a savings on the total mass of the object of 35 % in relation to almost identical Maslenica bridge.
The designer of the bridge was Dr. sc .Zlatko Šavor, the supervisor was IGH Zagreb - Dr.sc. Z. Marić, and the bridge was built in the period 2002- 2005 by the company “Konstruktor inženjering Inc.” from Split with the steel part built by the company “Đuro Đaković Ltd.” from Slavonski Brod. The bridge was opened to traffic together with the opening to traffic of the highway Zagreb –Split in 2005.

Stamp Issue: 2015.04.23

Reconstruction of the old bridge in Mostar

The Mostar Bridge is one of the greatest masterpieces of structural engineering of the Ottoman times. It is part of the oldest nucleus of the town and has great environmental value in its urbanistic structure. Its specific position is harmonized with the natural configuration of the terrain, while its architectural value has been achieved by the usage of basic structural elements. The surrounding mountains leave a deep impression on the viewers, together with the deep river bed of the blue-green river Neretva and the houses characterized by the typical ambiance significance for the 15th and 16th centuries. The oldest written document about medieval Mostar dates back to the 15th century, before the advent of the Ottoman Empire’s administrative management. The document was the work of Duke Stjepan Radivoj, (a Herzegovian nobleman). Little is known about the building of the bridge. What remained written are only memories and legends, as well as the name of the great architect Hayruddin. Even nowadays, when parts of the bridge have been rescued from the Neretva and examined all the constituent parts of the bridge, there still remains the mystery of how the scaffolding was built, how the stone got transported from one side of the river to the other, how the scaffolding endured the long period of construction, as well as numerous other “minute” constructional problems, those that we encounter nowadays despite the usage of the most modern technologies at our disposal. This speaks for the high quality of the builder’s expertise, his idea, never to be repeated or written down but realized in a work that doubtlessly belongs to the greatest engineering undertakings of its time. There were no archaeological finds to be discovered in the position where the present bridge with its towers fortifying it on both banks stand, which might draw to the conclusion that the bridge with its fortifications and the settlement that belongs to it could be dated to earlier periods than the Late Middle Ages. The fortifications together with the bridge were invaded by the Ottoman Turks round 1470, and there they organized a military outpost for further military attacks in western Herzegovina and Dalmatia. During the time of Ottoman administration, near the fortifications on the bridge, particularly on the left bank of the Neretva, a trading-crafts centre started developing, the origin of today’s Mostar. The suspension bridge built in the Middle Ages continued to connect the two banks of the river Neretva, and the Turks continued using it until the middle of the 16th century. Along the rather ramshackle wooden suspension bridge, in 1557, due to the order of Sultan Suleiman ‘the Magnificent’, the construction of the single span, stone arch bridge was built according to the project of the then supreme Turkish architect Kodja Mimar Sinan, and by the year 1566 it was erected and completed by his pupil and assistant Mimar Hayruddin. The medieval towers on the banks that guarded the approach to the bridge from both sides of the river, were reconstructed and extended many times, at the time of the Ottoman administration and particularly at the time of the Candian war, but basically retained all their essential elements that they had been given, probably in the 15th century, by their medieval builders. Around the Old Bridge a community developed that was to become a trading and crafts centre.

During the period of the last fifty years, this site was subjected to numerous conservation and archaeological research undertakings. The conservation work was supposed to examine and restore damage on the bridge and its accompanying towers, as well as check on the data about their building that were partially preserved in the reports of the later travel writers and some scattered historical sources. In the course of the research and the restoration work, the foundations of the bridge and the river banks have been underpinned and consolidated, and the supportive parts of the bridge, together with the support pillars have been injected. The bridge arch has also been injected, and the damaged stone blocks exchanged. Lesser damage was repaired by mortar mixed from white cement and ground limestone that was used in building the bridge.

The Old Bridge in Mostar was destroyed by shelling in November 1993, in the course of the recent wartime events. Its rebuilding began in the year 2002 under the auspices of the World Bank and the Bank for Development of the Council of Europe, with funds donated by countries like Italy, Turkey, Croatia, The Netherlands and France. After two years since the beginning of its restoration and almost 15 million US dollars spent, the work is approaching its end. The main responsibility lay upon the Turkish company ERBU, specialized for the restoration of Ottoman bridges, working under permanent supervision of specialized Croatian companies and experts. From the oldest times up to the present, the Old Bridge has remained the symbol of Mostar. The bridge also remains a permanent attraction for the population as well as tourists. The tradition of taking jumps from the top of the arch into the river also remains a symbol that will be transferred to future generations.

Stamp Issue: 2004.07.23

Bridges and viaducts

Old Josephine Road was passing along Salopeke Modruške, a fortification of Modruš and next to the St. Nicholas monastery at Kapela. In order to surmount the steep rocks above the Tounjčica canyon, a 45 m long stone bridge with three openings was built. The bridge was erected at the time when the building of the road began, in 1775 and from 1833 to 1835 the road was renovated from Senj through Mala Kapela to Tounj in the length of 76 kilometres. New road was meant to avoid steep terrain, so from Josipdol to Donji Modruš it had a smaller number of rises than the old route. Then the building of the second floor of the bridge at Tounj began. The lower floor of the bridge, built in 1775 was in use as an integral construction for about sixty years. In 1836 the second floor was added to it, what made steep rises and descents of the road toward the bridge as well as sharp curves somewhat more moderate.

According to the preserved original designs and photographs, it is evident that on the first part of the bridge from both sides there were four statues. Above the pillars there were huge statues of Roman soldiers, while smaller statues above base pillars disappeared. Before the Second World War only their pedestals were preserved. On both sides of the bridge, on the parapet, there were slabs with inscriptions. On the first slab of white limestone there was an inscription in Latin: “To the memory of the difficult passage that in May 1775 the Emperor Joseph II, father of homeland, first undertook and ordered that new road be built under the guidance of the enthusiastic constructor, colonel Struppi”. On the other slab made of dark limestone there was Latin inscription: “Ferdinand I, Emperor of Austria, religious, happy and illustrious, added to the bridge of the divine Joseph II, Roman Emperor, erected between steep shores, a new, easier access and renovated the whole road in 1836  entrusting the works to Kajetan Knežić, supreme commander of border guards.”
On the bridge on each floor there are three openings spanned by semicircular vaults. The vaults are 5.6 m large and the pillars are 2.6 m wide, with parapet 9m.  The second floor of the bridge is 12.35 m above water. Between the parapets the bridge is 7.8 m wide and with parapets 9 m. The width of the roadway is 6 m. The height of the parapet is two times multiplied by 0.6 m. Pedestrian pathways are 0.9 m wide and the upper floor is 5.6 m high.

During Second World War a greater part of the upper floor, three vaults and their pillars were destroyed. Later, a provisional wooden crossing was constructed over these remains.  In 1956 at the Institute for Wooden and Massive Bridges of the Technical Faculty in Zagreb a technical elaboration for bridge renewal in its original form was prepared. The statues and commemorative slabs from the bridge are partly preserved. One statue is exposed near the bridge, on an elevation not far from Tounjčica, while another statue with the commemorative slab from the year 1836 is situated in the yard of the Frankopan Castle in Ogulin.

Stamp Issue: 29.04.2013