Innovative approach for surveying slope stability in road infrastructure rehabilitation

Abstract

The objectives of the repair, maintenance and rehabilitation of the road network in mountainous terrains focus on the study of the structural condition of the rock slopes. An innovative approach to structural mapping and analysis was implemented within the framework of a survey project for a road section of road II-35 Troyan-Karnare, known as “BEKLEMETO”. This section begins with a long and steep descent from the Beklemeto saddle (at 1,525.5 m above sea level), passes through numerous bends on the southern rocky slope of the mountain and after 22.7 km descends into the northwestern part of the Karlovska valley, to the village of Karnare (at 562 m above sea level). The study of the structural disturbance provides an opportunity to present the groups of joints that have developed intensively on the rock slopes passing near the Republic Road II-35 in the section between Beklemeto and Karnare. Over the years, these slopes have been subjected to weathering, erosion and collapse processes, which have led to changes in the physical and mechanical properties of the rocks forming the slopes. The technology of mobile ground laser scanning, which is a suitable method for covering the complex characteristics of the terrain, was chosen for the research. The implementation of this technology was carried out through an integrated complex. Using this method, a total of 18 representative sections within the road II-35 “BEKLEMETO” were studied, and the number of measured cracks exceeded 13,000. The total length of the researched sections is over 10,770 m. In processing, short cracks with a length of less than 0.8 m, which do not affect the structural disturbance of the rock formations, are excluded. These data and studies are essential for the planning of effective measures to maintain and rehabilitate road infrastructure in complex mountain conditions.