Soil liquefaction and ground settlements in 6 February 2018 Hualien, Taiwan, earthquake

Soil liquefaction and ground settlements during an earthquake of M _L 6.2 that took place on 6 February 2018 in Hualien, Taiwan are presented in this article based on the results of a field reconnaissance that focused on geotechnical aspects. Cracks of road pavement with sand eruption were found in a former wetland. Slight settlement of several residential buildings that are located near the Meilun River was observed. In addition, minor sand boils and lateral spreading occurred at the riverbanks of the Meilun and Hualien Rivers. In general, liquefaction and ground settlements in Hualien City were sparse and localized in weak ground, causing no damage to structures and facilities. However, in the Port of Hualien, ground settlements up to 50–60 cm, as well as considerable pavement cracks, were induced in the backland of several gravity-type wharves, especially those in the jetty area. Many of the cracks and settlements were accompanied by eruption of the mixture of sand and gravel with a maximum grain size up to 10 cm. These phenomena were due to the liquefaction of the backfill material. Fortunately, there was only scarcely noticeable tilt and structural damage of the caisson quay walls and scarce settlement of the apron. Thus, the serviceability of these wharves was not greatly influenced.