Competing against Time: Report of the Governor's Board of Inquiry on the 1989 Loma Prieta Earthquake

Abstract

A Board of Inquiry was appointed by the Governor of California to investigate the 1989 Loma Prieta Earthquake. The formation of the Board was prompted by earthquake damage to bridges and freeway structures and the desire to know not only what happened, but how to prevent such destruction in future earthquakes. The Board made fifty-two specific findings and eight recommendations. They identified three essential challenges that must be addressed by the citizens of California, if they expect a future adequately safe from earthquakes: 1) ensure that earthquake risks posed by new construction are acceptable; 2) identify and correct unacceptable seismic safety conditions in existing structures, and; 3) develop and implement actions that foster the rapid, effective, and economic response to and recovery from damaging earthquakes The Loma Prieta earthquake should be considered a clear and powerful warning to the people of California. Although progress has been made during the past two decades in reducing earthquake risks, much more could have been done, and awaits doing. More aggressive efforts to mitigate the consequences of future, certain earthquakes are needed if their disastrous potential is to be minimized and one of the most fundamental of responsibilities of government is to be fulfilled—to provide for the public safety. The Governor signed an Executive Order implementing the principal recommendations of the Board that may prove to be the most significant step to improve seismic safety within the State taken in the last several decades. It establishes the policy that all state owned and operated structures are to be seismically safe and that important structures are to maintain their function after earthquakes.

Earthquake loss estimation for the Kathmandu Valley

“…The bed rock outcrop motions were amplified about five times. In the 1989 Loma Prieta earthquake, major damage occurred on soft soil sites in the San Francisco -Oakland region where the spectral accelerations were amplified two to four times over adjacent rock sites (Housner 1989), and caused severe damage. It shows that surface-level peak ground acceleration and spectral acceleration values can be different from bedrock values, depending on local soil conditions.…”

Seismicity of the United States, 1568-1989 (revised)

“…(Ref. 74,574,579,594,595,596,606,607 25). The location of this earthquake is very uncertain and has been postulated to have occurred in western Colorado or southern Wyoming.…”

Application of inelastic damage analysis to double-deck highway structures

“…The three-bent test structure mentioned above was tested to failure by loading all three bents laterally with hydraulic jacks [Housner et al, 1990]. A plot of the lateral load per bent vs. the upper level displacement is shown in Fig.…”

“…Deukmejian titled "Competing Against Time" [Housner et al, 1990] which draws on the observations and analyses of many investigators.…”