H. Bolton Seed

The failure of Teton Dam

Abstract This paper reviews the events leading to the failure of Teton Dam in Idaho on June 5, 1976 and the investigations, conducted over a period of about eight years, to determine the cause of the failure. Conclusions are presented regarding the probable trigger mechanisms which initiated the failure, the mechanics of failure and the significant lessons concerning earth dam design and construction resulting from the investigations.

Soil-structure interaction analyses by finite elements — State of the art

Abstract In this paper the authors have attempted to summarize the current capability for evaluating soil-structure interaction effects during earthquakes using finite element procedures. A concise summary of methods available, together with their capabilities and relative costs is presented. It is suggested that finite element procedures provide a powerful tool for use in the design of nuclear plants, especially for embedded structures, and their applicability in this respect is illustrated by comparing computed results with those recorded in a nuclear plant during a strong motion earthquake. It is concluded that when the methods are used in conjunction with good engineering judgment and with full recognition of their limitations, they provide evaluations of response with a level of accuracy entirely adequate for engineering design.

Earthquake Effects on Soil-Foundation Systems

The damage resulting from earthquakes may be influenced in a number of ways by the characteristics of the soils in the affected area. Where the damage is related to a gross instability of the soil, resulting in large permanent movements of the ground surface, association of the damage with the local soil conditions is readily apparent. Thus, for example, deposits of loose granular soils may be compacted by the ground vibrations induced by the earthquake, resulting in large settlements and differential settlements of the ground surface. Typical examples of damage due to this cause are shown in Figures Figure 16.1 and Figure 16.2 Figure Figure 16.1 shows an island near Valdivia, Chile, which was partially submerged as a result of the combined effects of tectonic land movements and ground settlement due to compaction in the Chilean earthquake of 1960. Figure Figure 16.2 shows differential settlement of the backfill of a bridge in the Niigata earthquake of 1964.

Re‐assessing liquefaction resistance curves: International correlation of the Standard Penetration Test

A major part of the US‐Japan Co‐operation Programme concerns earthquake research; results are presented here of a study of field practices in those countries and elsewhere of the Standard Penetration Test, in which the equipment and procedures used led to anomalies in energy ratios and N‐values. Accordingly a standard energy ratio of 60 percent is recommended, and this has been applied in a re‐evaluation of the accumulated data base relating SPT to liquefaction susceptibility.