Mirna Bridge

45.32944444444413.626666666667Koordinaten: 45 ° 19 '46 "N, 13 ° 37' 36" E

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Mirna

The Mirna Bridge is located between junctions Nova Vas and Višnjan Croatian A9 in Istria. It spans the Mirna river valley, with its broad. It is about 1.3 km long and has two lanes. The opening to traffic took place in 2005. The bridge is one of the most striking points of the highway. The bridge was designed by Zlatko Savor.

The A9 Umag- Kanfanara was raised in June 2011 to motorway status. This extension works included no new construction of a second parallel roadway. This extension should be recuperated in the years 2013-2015.

Description

The bridge structure consists of 22 sheets together: 1 × 51.07 m, 15 × 66.5 m, 70.1 m × 1, 2 × 50.01 m, 61.1 m × 1, 1 × 42.6 m and 1 × 30.5 m. The original design of the bridge went from sheets with 66.5 m from. The ultimately implemented design was influenced by the soil condition and the arrangement of the riverbed and canals under the bridge. Since the base has an extremely low base - load capacity, a reduction in weight was very important. For this reason, the design has two weight-reducing elements: longitudinal steel beams and columns with header bar at different heights. The latter reduces the required volume of concrete of the pillar, and thus the weight of the structure, while the bridge gets a curved concave surface.

As the valley holds a worth protecting arable land of high quality, this was taken into account in the design of the pillar base. The height of the reinforced concrete piers varies between 13.45 m and 40.03 m, and each of the pillars crowned by a head beams. The pillars have an I-section, the webs are aligned along the road axis. The outer pillars (P1, P2, P20 and P21 ) are designed as shallow foundations, while the inner pillars have piles. The superstructure consists of two prefabricated longitudinal beams of constant depth with a spacing of 550 cm, in conjunction with deck slab and transverse beams. In terms of structure, the superstructure is a continuous 1354.86 m long carrier over 22 arches, which follows a horizontal and vertical alignments. The cross section of the superstructure consists of two massive steel beams in the I-section of constant depth.

Traffic

There are regular traffic counts conducted by the Bina Istra, which operates the bridge and the entire A9, and published by Hrvatske ceste. Substantial variations between annual and summery traffic volume are due to the fact that the bridge on the route to tourist destinations in Istria and the Adriatic coast lies. The count success on the basis of selling toll ticket.