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oughly 50 centimeters, with numerous areas experiencing settlements greater than 100
centimeters (Hamada et al. 1996; Shibata et al. 1996).
Figure 2.1: Pajaro River Bridge Damage
This subsidence caused severe damage to underground utilities and led to the settlement of
approach fills adjacent to bridge abutments. The most obvious and destructive ground failures
were found in waterfront areas, and were particularly damaging to bridge foundations. They
often exposed pile heads in many of the warehouses, buildings, and bridges with small
penetration depths into the pile caps. Concrete piles that were well embedded into pile caps
exhibited shear failures and/or extensive cracks due to large bending moments near the pile
heads. For steel pipe piles with fixed-head conditions, plastic hinge formation was often
observed near the pile cap. In lightly reinforced pile caps where free-head conditions were
evident, piles either rotated or became detached from the cap. The damage to the piles in turn
caused damage to foundation beams and superstructure, if the foundation beams were not rigid
enough. Otherwise, the building simply settled or tilted with little damage to the superstructure
(Tokimatsu et al. 1996). Other pile and bridge failures that occurred during the Kobe Earthquake
are presented in Section 2.3.5.
The previous observations illustrate the type of damage that may be experienced as a result of
liquefaction-induced ground failures such as lateral spread and ground subsidence. Based on the
case studies, observations and/or impacts from liquefaction include the following.
1. Lateral ground displacements have been extremely damaging to bridge foundations and
abutments.
2. Movement of foundation elements may create large shear forces and bending moments at
connections and compressional forces in the superstructure.
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