At the beginning of this year, the 3.73-km-long forest road called “Sermuliņa loks” was put into operation in Viesīte Forest District, LVM South Latgale region.
The construction of this road took more time than planned, because the initial solution of the construction design was flawed, namely, it could not ensure the stability of the road structure in its peat-covered section. Last May, the builder found that for this reason it was not possible to form structural layers of the road on one of the road sections. At this time, removal of peat was not possible either, as the estimated volume of unusable soil that would have to be removed and the useful mineral soil that would have to be brought in instead was very large and would therefore lead to significant additional costs. In order to look for other solutions, both the author of the construction design and LVM Forest Infrastructure Control specialist Ivars Caune were invited, as a result of which the construction design was redesigned, at the same time looking for the most economically advantageous solution.
“We changed the original solution and included in the design two new types of road construction. The first type of construction provides for the use of geosynthetic materials, where the geotextile would separate the peat soil layer from the base of the pavement, whereas the geocomposite would strengthen the road structure. The geocomposite was inserted between the base of the pavement and the road surface. Its task is to distribute the load evenly over the entire road structure. This type of construction was used at a location where the peat layer was 1.4 to 1.7 metres deep. The second type of construction was the use of geosynthetics together with a log cover. In such case, the log cover served as a natural peat load-bearing enhancer and ensured that the structure would settle evenly. In turn, the task of the geotextile was to separate the base of the pavement from the reinforced ground surface, and the task of the geocomposite was to strengthen the road structure. This second type of construction was used at a site where the peat layer was from 1.7 to 2.10 metres deep,” tells Ivars Caune, LVM Forest Infrastructure Control Specialist.
Thanks to the use of both types of construction, it was possible to ensure that the forest road was built in full and at the planned location.
The author of the construction design is SIA “Polyroad”, the construction works were performed by SIA “Ošukalns”, the construction supervisor was SIA “Būvju profesālā surveyība”, but the responsible forest infrastructure specialist was Raimonds Papsujevičs.