Shales and Slates of El Sillar (Bolivia). Description of degradation processes

“El Sillar” is a stretch of main Bolivia’s highway, where landslides problems are frequent. Geological factors and environment conditions (with variations in humidity and high rainfall) are the main factors for degradation progressive of rocks. In fact, chemical and physical weathering are also responsible for a time-dependent weakening of the rock, which combined with other phenomena can cause slope failure. At the present time, there is few research on the behavior of these rocks.

Based on laboratory data, tests at microscopic level, and field observations, this paper examines causes and processes of deterioration of El Sillar’s clay shales. Additionally, describes parameters calibration of C-CASM model by triaxial tests.