Fifteen years have passed today since the opening of the Razdrto — Vipava expressway section through Rebernice. We designed the Šumljak and Tabor viaducts on the section that is considered one of the most demanding on the Slovenian motorway network because of the steep and unstable slopes of cliff called Nanos. There are many road structures on this section, the longest of which is the 671-meter-long Šumljak Viaduct. A sloping viaduct consists of two separate structures that bridge a steep slope relatively low to the ground, at a height of up to 20 meters. The construction of the viaduct was extremely demanding, from a technical standpoint, due to the slope of the terrain, the S-shaped axis, and the geological characteristics of the ground. To enable safe traffic in a demanding and variable area (wind, cold, snow, changing profiles), the entire route through Rebernice is boldly designed. The viaduct also crosses a very large and deep slow landslide (moving at a rate of 8mm/year), so to ensure safety, constant monitoring of the landslide and the viaduct structure is carried out.
The Tabor viaduct is designed as two separate structures that are independent of one another due to the distance between the axes and the close proximity of the tunnels. The prestressed slab concrete structure spans over 13 fields on the left and 12 on the right and is 375 meters long on the left and 326 meters on the right. Since there is good load-bearing soil in the valley it spans, its foundations are mostly shallow.
The section of the expressway as it passes through Rebernice is 10,980 meters long and overcomes a height difference of 497 meters on the way from Razdrto to the junction Vipava. The section is part of the H4 expressway through the Vipava Valley from Razdrto to the border crossing with Italy.
Project details:
Šumljak ViaductProject details:
Tabor Viaduct
