Damage to culvert under memorial stadium, University of California, Berkeley, caused by slippage in the Hayward fault zone

Abstract

Slippage on a fault plane or sheared band in the Hayward fault zone has seriously damaged a cast-in-place concrete box culvert which carries the waters of Strawberry Creek under the University of California Memorial Stadium at Berkeley, California. Right-lateral movement of the fault or sheared band has offset the southwest-flowing creek so that the southwest portion has moved northwest with respect to the northeast portion. The two parts are connected by a northwest-trending section about 1,200 feet long, which flows in the culvert under the stadium. The fault crosses the culvert at a low angle, trending about 20° more to the north than the culvert, so that both tension and shear have been exerted on the culvert by right-lateral movement of the fault since the culvert was built in 1923. Two transverse cracks 1 inch wide and about 5 feet apart were noted when the culvert was inspected in 1948. In 1965 the maximum width of the cracks was $312$ inches and the section of the culvert between the cracks appeared to have rotated clockwise. Total average separation of the cracks due to tension is about 4.1 inches; lateral offset of the culvert is 1.25 inches. Movement along the fault is estimated at 0.1 inch per year over the 42 years since the culvert was built.