Prelimary Geotechnical Engineering Observations of the Tecomán, Mexico Earthquake of January 21, 2003

The 21 January 2003 Mw 7.6 Tecomán, Mexico Earthquake caused significant damage to the coastal region of the state of Colima, Mexico. This paper presents an overview of observations made by the United States National Science Foundation (NSF)-sponsored geotechnical engineering reconnaissance team, which visited the affected region one week following the earthquake. The team visited and documented sites including major cities, industrial facilities, and transportation routes. There were a number of important geotechnical engineering features of the earthquake. Liquefaction and consequent strength loss, ground settlement, and lateral spreading, alone or in combination, damaged the Port of Manzanillo, the capital city of Colima and other locations. The earthquake triggered thousands of landslides, the vast majority of which were disrupted landslides, specifically rock falls, rock slides, soil falls, and disrupted soil slides. Damage surveys by the reconnaissance team in the conjoined cities of Colima and Villa de Álvarez clearly indicated localized areas of high structural damage concentrations, suggesting that site effects may have contributed to overall damage