The Distribution of Earthquake Damage to Underground Facilities during the 1976 Tang-Shan Earthquake

This paper, through description and analysis of the performance of underground facilities during the magnitude 7.8 Tang-Shan earthquake of 1976, indicates that, in the area of strong surface shaking, damage to underground facilities decreases exponentially with depth to 500 m (1640 ft). Below this depth, damage remains constant. In addition, the rate of reduction of earthquake shaking away from the source fault is greater in the subsurface than on the surface.