The northern coast of São Paulo State is a region with many highways that connect the coastal cities to each other and to the State capital or other cities. These highways need to traverse the Serra do Mar mountain range. And because the State capital and other major cities are on the plateau, there is a need to overpass 700-800 meters of vertical distance in just a few kilometers of horizontal distance. Since many of the highways are around 50 years old, their design and construction had a different approach and pattern from current highway standarts. This makes the region's slopes very prone to many types of failures, like rockfalls and landslides. The highway sector studied in this paper was already studied by the some of the authors, for the application of RHRS. Here, we present an application of the Q-Slope method on the same slopes.
This work presents an experimental approach of using the Q-Slope method (Barton & Bar, 2015) in a highway sector already studied (Castilho et al., 2018) with the Rock Fall Hazard Rating System method (RHRS – Pierson et al. 1990, Budetta 2004). We do not intend to exhaust the technical aspects of the methods nor technical aspects of combining both. Rather, we seek for a fast and practical way to evaluate highway slopes that are clearly compromised and need methods to define improvement and correction planning. The authors think that the Q-Slope method fits perfectly the motto of the RHRS analysis, that is, a low cost, fast and pratical method to evaluate slopes' stability, and was a natural addition to the RHRS analysis.
The northern coast of São Paulo State is a region with many highways, that connect the coastal cities to each other and to the State capital or other major cities. These highways need to traverse the Serra do Mar mountain range, one of the most remarkable relief features of Brazil's southeastern coast. And because the coatal cities are close to the sea level, and the State capital and other major cities are beyond the Serra do Mar, there is a need to overpass 700-800 m of vertical distance in just a few kilometers of horizontal distance. Since many of the highways are around 50 years old, their design and construction had a different approach and pattern from current highway standarts: very sinuous alignments, high gradient ramps and vertical rock slopes with little to no stabilisation solution or support. This makes the region's rock slopes very prone to many types of failures and problems, like rockfalls and landslides.
