On the reconstructed bridge over the Gauja near Rāmniekie last Thursday, there was a special bustle.
The last metal structure of the bridge was placed on the supports, and according to the responsible construction manager Sandis Junkers, this is an important moment in the work process. Especially because the metal structure was placed on the supports with the sliding method, which is very rarely used in Latvia. According to the information of VAS “Latvijas Valsts ceļi”, until now it has only been used in the construction works of five bridges in Latvia.
It has already been written that the work on the reconstruction of the bridge began last fall, when the bridge was closed to traffic, and those who used the bridge on a daily basis had to choose a detour.
The reconstruction is designed so that there is no need to rebuild the existing bridge supports, as they are in good technical condition. The new superstructure has been adapted to the bearing capacity of the supports, the most technically and economically advantageous option has been chosen – a steel concrete girder bridge, which is much lighter than a monolithic reinforced concrete bridge, thus there is a much smaller load on the foundations.
The almost 100 m long bridge over the Gauja near Rāmnieki is large by the standards of Latvian roads, so it is impossible to place such long and heavy beams on the bridge supports from the shore with cranes, explains “Latvijas Valsts ceļi”. Building “stays” to support the structure from below, which is the most commonly used method, would be difficult given the large spans and the changing waters of the Gauja. By sliding steel beams onto the supports, the problem is solved, because the beams serve as “holds”, on which the bridge slab and the rest of the superstructure can be molded and concreted.
According to the technology used, spans of steel beams were built on the shore and then pushed onto the piers. Two stages of sliding have already been carried out in the winter, by sliding the support structure from the left bank to the first river support and then the second. As “Latvijas Valsts ceļi” informs, the driving speed is approximately six meters per hour.
The most important thing in this work is accuracy, also that all employees have worked together, everyone knows what they are doing, says construction manager S. Junkers: “Considering that such a process is rarely used for placing a bridge structure, it is a big challenge for the builders, but gives an opportunity to gain new and useful experience.”
It turns out that Latvian specialists were once among the first in the world to use the sliding method, the first such project was implemented during the design and construction of the Lorupe overpass in the 60s of the last century.
It has already been written that the construction works of the Rāmnieku bridge are being carried out by SIA “ACBR” for the contract price of EUR 3,197,536.01, the client of the works is “Latvijas Valsts ceļi”.
The works are proceeding according to schedule, and the bridge will be ready for use in the fall. At the moment, it is planned that in connection with the rise of the water level in Gauja, the bridge construction work will be interrupted from March 18, which will end when the water level has dropped enough.
“When planning the construction works, this aspect was also taken into account, so it will not significantly affect the deadlines,” says S. Junkers. “Construction went on all winter without interruption, despite the weather conditions, everything was done to keep the work going.”
After the reconstruction, the bridge will be safer and, most importantly, wider. If before the reconstruction there was one-way traffic on the bridge, its width was 4.2 meters, the roadway of the new bridge will be seven meters wide, and there will be two-way traffic on the bridge, according to the information of “Latvijas Valsts kētu”. A 1.5 m wide steel sidewalk will be built for pedestrian traffic, but the pedestrian bridge built in 1977 is planned to be demolished after the reconstruction of the road bridge.
It has already been written that it is planned to rebuild the road surface in the approaches to the bridge by laying asphalt in two layers: on the Vaidava side – from the bridge to the exit to the parking lot, including the exit, and on the Cēsi side – in a section about 450 meters long. It is also planned to arrange exits and connections, as well as bus stops.
