On the Effect of Thermally Induced Stresses in Failures of Some Rock Slopes in Rio de Janeiro, Brazil.

Previous studies have indicated that many rock slope failures in Rio de Janeiro, Brazil, occur during relatively dry periods when there is little, if any, rainfall. In the present paper, we describe these events and propose possible mechanisms for their occurrence. It is believed that daily fluctuations in temperature may create thermally induced stresses of enough magnitude to propagate fractures already existing in the rock mass. Laboratory experiments were conducted in order to measure temperature variations in a fractured rock system. Using the experimentally obtained data, we carried out numerical analyses in order to verify whether temperature-related stresses were indeed able to propagate fractures existing in the rock mass. The results obtained indicate that cycles of temperature change over time, especially during the colder months of the year can indeed create stress conditions in the rock mass able to propagate existing non-persistent joints, and ultimately lead to failure of the rock slope. [ABSTRACT FROM AUTHOR]