Bludov Bypass: A Modern Stream Crossing Solution

By: ViaCon Poland

The Challenge of Span and Soil

The new Bludov bypass, a four-lane highway near Sumperk in the Czech Republic, needed to cross a stream. However, engineers faced a challenge. The crossing required a large span. In addition, the soil conditions in the area were poor. These factors made traditional stream crossing solutions difficult.

ViaCon Multiplate: An Efficient Stream Crossing Solution

To address these challenges, engineers chose a ViaCon Multiplate system. This system uses a closed, corrugated steel plate structure. It offered several advantages over other stream crossing solutions. First, it provided a long service life. Second, it allowed for a short construction time. This made it an ideal solution for the Bludov bypass.

Design and Construction Details

The Bludov stream crossing features a pipe-arch shaped structure made from corrugated steel plates. The crossing spans 32.7 feet (9.96 m) with a rise of 24 feet (7.32 m). Because of this large span and the slightly skewed angle of the crossing, the design used 0.3 inch (8 mm) thick plates and 7.9 x 2.2 inch (200 x 55 mm) corrugations for sections over 16.4 feet (5 m) high. To ensure stability, the ends of the structure were reinforced with cast-in-place concrete collars. Crews installed these collars before backfilling the structure. This approach is a robust stream crossing solution for challenging sites.

Stream Management and Corrosion Protection

The structure also incorporates a channel for the stream. This channel, made of quarry stone, sits in a concrete base at the bottom of the structure. To protect the steel plates from corrosion, all surfaces that would be in contact with backfill received a 11.8 mil (300 µm) thick epoxy coating. All visible plate surfaces and bolt heads were also coated with a 5.5 mil (140 µm) thick epoxy paint and then finished with a 3.1 mil (80 µm) thick layer of polyurethane paint. After assembly, workers coated all accessible bolt threads and nuts on the backfilled side with three layers of epoxy paint, providing the same level of protection as the surrounding plates. This attention to detail is important for long-lasting stream crossing solutions.

Final Steps and Project Success

After the structure was assembled and painted, crews backfilled it with crushed gravel. To further protect the structure and prevent water damage, they installed an HDPE membrane within the fill above the structure. This membrane acts as a waterproofing layer. The construction process was completed efficiently, and the bypass opened to traffic at the end of 2023.

The Bludov bypass project demonstrates the many benefits of the ViaCon Multiplate system as a stream crossing solution. By eliminating the need for concrete pile construction, the project saved both time and money. The use of durable steel ensures a long service life for the crossing. Furthermore, the efficient construction process minimized disruption and allowed the bypass to be put into service quickly. This highlights the advantages of choosing innovative stream crossing solutions.