Estudio del deslizamiento del cerro Cruz de Shallapa del distrito de Chavín de Huantar en la Región Ancash y propuestas de medidas de contención

Abstract

The landslide that occurred on June 30, 2022, in Chavín de Huantar had a material and psychological impact on the community, exacerbating conditions of vulnerability and testing the local government's capacity to respond to natural disasters. The landslide took place on the eastern limb of an anticline of the Oyón Formation on a nearly vertical arrangement. The landslide was studied by back analysis of the failure surface and resulted in shear strength parameters of the sandstone rock discontinuities and shale rock, while laboratory results determined the strength of the sandstone rock. The back analysis reveals that the strength properties of the sandstone discontinuities at the time of failure were 300 kPa and 33° for cohesion and friction angle respectively, assuming peak strength of 40 kPa and 20° for the shale. It is concluded that the landslide was primarily caused by a set of discontinuities in the sandstone, dipping between 40° and 46°, as well as by the location of the geological contact between the sandstone and the shale. Based on the properties obtained from the back analysis, it is concluded that the current slope is stable. A scenario is proposed where the slope is unstable and it is estimated that the landslide produced would reach the Jirón Wiracocha, so the construction of an impact berm at the foot of the slope, with a height greater than or equal to 8 m, is recommended as a preventive measure.