Stabilization through improved drainage using stone mattresses

Efficient and sustainable forest road construction is essential for the forestry industry, ensuring accessibility while minimizing environmental impacts. This study investigates the effectiveness of stone mattresses, also known as French mattresses, as a stabilization and drainage technique for forest roads in Sweden. A field trial was carried out on a forest road in Dalarna County, involving two nearby sections, Section 1 and Section 2, each approximately 200 meters in length. Each section was divided into two parts: one stabilized with stone mattresses and the other without, for comparison purposes. Stone mattresses, composed of coarse rock wrapped in geotextile, facilitate water drainage while enhancing road durability. Various tests, including lightweight deflectometer (LWD) measurements, profile surveys, material analysis, moisture assessments, and visual inspections, were performed before and after exposure to traffic and weather conditions. Results showed that road sections with stone mattresses exhibited improved bearing capacity, the rate of change in dynamic deformation modulus (Evd) was 12–23% higher than on unstable road surfaces. Additionally, these sections exhibited reduced rutting, indicating improved structural integrity and resilience. Further optimization of construction methods, as discussed in this study, could enhance efficiency, making the implementation of stone mattresses even more effective for stabilizing forest roads in challenging conditions.