The causes and conditions of landslide hazard in a 35 m deep, 240 m long rock excavation located at 46 km of the Izvestkovaya - Chegdomyn line, passing in the eastern marginal part of the Bureyn middle massif, which is central to the Amur geoblock of the Pacific mobile belt, characterized by complex and diverse engineering and geological conditions, were studied in detail. Seven fracture systems have been identified, three of which are major. A general conclusion is valid for the whole caving area: the fracture hollowness of rocks is abnormally high, and the blockiness of rocks is dense. Three zones have been studied in the weathering crust, their total thickness is about 40 m. Stability of excavation slopes is a little more than unity, but during earthquakes of intensity 4.0 points and more, collapses up to several hundred cubic meters are possible.
