EVALUACIÓN DEL POTENCIAL DE LICUACIÓN DE SUELOS EN TARQUI, ECUADOR

Abstract

The Tarqui zone, located in the city of Manta, in the Ecuadorian province of Manabí, was destroyed due to the earthquake of April 16, 2016 with epicenter near the same province. The earthquake with moment magnitude (𝑀𝑀𝑤𝑤) 7.8 triggered the phenomenon of liquefaction and consequently settlements and displacements in the soils of the zone. Based on the 27 borings performed in-situ by the standard penetration test (𝑆𝑆𝑆𝑆𝑆𝑆) and the 26 soundings performed by the piezocone test (𝐶𝐶𝐶 𝐶𝐶) the liquefaction potential in Tarqui was evaluated quantitatively in terms of the factor of safety against liquefaction (𝐹𝐹𝑆𝑆𝑙𝑙𝑙𝑙𝑙𝑙), liquefaction potential index (𝐿𝐿𝐿 𝐿𝐿) and the liquefaction severity number (𝐿𝐿𝐿 𝐿𝐿), vertical settlements (𝑆𝑆𝑣𝑣−1𝐷𝐷) and lateral displacements (𝐿𝐿𝐿𝐿𝐿𝐿) were estimated based on the simplified semi-empirical procedures of (Boulanger & Idriss, 2014) through the development of an Excel spreadsheet (JLiq SPT). For the 𝑆𝑆𝑆𝑆𝑆𝑆 borings, the liquefaction susceptibility of the fine-grained soils was evaluated; additionally, for the 𝑆𝑆𝑆𝑆𝑆𝑆 and 𝐶𝐶𝐶 𝐶𝐶 tests, the severity of the liquefaction induced ground damage (𝐿𝐿𝐿𝐿𝐿𝐿𝐿𝐿) was evaluated based on the methodologies proposed by (Bray & Sancio, 2006) and (Ishihara, 1985), respectively. 11 comparisons of the results obtained from nearby 𝑆𝑆𝑆𝑆𝑆𝑆 and 𝐶𝐶𝐶 𝐶𝐶 tests were made. Contour maps of the spatial distribution of the 𝐿𝐿𝐿𝐿𝐿𝐿, 𝐿𝐿𝐿 𝐿𝐿 and 𝐿𝐿𝐿 𝐿𝐿 were made. Site vulnerability of liquefaction was shown to be very high in most cases.