The Hague tow-bike viaduct | Final phase of construction Jan Linzelviaduct near The Hague started

The final phase of construction of the Jan Linzel Viaduct^*, the bicycle bridge over the A4 near The Hague between the Ypenburg neighborhood and Golf Course Leeuwenburgh, has begun. Before that, the spans over the national highway and the abutments at the golf course were constructed this summer.

The bicycle viaduct is part of the Trekfietstracé, a fast bicycle route between Ypenburg and The Hague city center. "The steel bicycle bridge is approximately 335 meters long, 6.5 meters wide and features a bicycle and footpath," said Johan Peek, project manager at Dura Vermeer Infra Regio Zuid West, which is realizing the construction. "The viaduct over the A4 connects to the already existing coupure in the noise barrier at Ypenburg and continues to Golf Course Leeuwenbergh in the Hague Vlietzoom." 

The bridge sections were partially transported by road with special heavy transport.

Construction

The bridge consists of a steel superstructure resting on six precast concrete piers and two concrete abutments. The superstructure is composed of nine separate bridge sections made at Hillebrand ASK Romein in Zeeland. Four bridge sections will form the two main spans over the A4 motorway as of August 2019; the other five bridge sections will form the approach bridges along the golf course. The largest span over the national highway between the pillar and abutment at Ypenburg is 85 meters. For this purpose, two bridge sections of 54 and 31 meters were placed against each other. The approach bridges on the Vlietzoom side have spans of 35 meters. There, the bridge sections are placed directly on the precast concrete piers. The holding point of the bridge is on the Ypenburg side. The slender steel structure contains transverse bulkheads every 3.8 meters with continuous troughs and a skin of 10-millimeter-thick steel. 

Close cooperation between Dura Vermeer and Hillebrand in realizing tow-bike viaduct.

Seamless

Peek: "All the bridge sections are structurally connected so that there are no expansion joints along the entire length. With the exception of one joint on the Vlietzoom that has to accommodate the compression and expansion due to temperature changes (up to 35 centimeters). The rest are seamlessly joined together, reducing the need for maintenance."

As little disruption as possible

One challenge was that construction should cause as little disruption as possible. Therefore, the decision was made not to make the steel bridge on site, but at Hillebrand. In order to install the four elements over the main and parallel lanes of the A4, they had to be transported from Zeeland to The Hague. First by ship to Schiedam and from there by special road transport to The Hague. Peek: "The A4 had to be closed off for this. At the same time, we could then also place 750-ton cranes to lift the bridge sections into place." 

Two main spans of 85 meters each.

Out of sight

Another challenge is that Golf Course Leeuwenbergh will have the viaduct "in its backyard. "To ensure members' enjoyment of the game, we constructed a temporary tee (teeing area) so we had room to realize the bridge. Installing an earth wall (20,000 m³) keeps the bike bridge out of sight as much as possible. And by providing it with planting, the earth embankment blends in nicely with the surroundings. At the end of September 2019, we will place the approach bridges, which are currently being connected. Soon we will start the reconstruction of the golf course and the ground wall, to be delivered in the spring of 2020."    ν  

^* Jan Linzel was the oldest Dutch Air Force veteran and the last Dutch fighter pilot to fight against the Luftwaffe from Ypenburg airfield in the May days of 1940. He passed away in May 2019.