The Over-Prediction of Seismically Induced Soil Liquefaction during the 2016 Kumamoto, Japan Earthquake Sequence

Abstract

Following the M7.0 strike-slip earthquake near Kumamoto, Japan, in April of 2016, most geotechnical engineering experts believed that there would be significant soil liquefaction and liquefaction-induced infrastructure damage observed in the densely populated city of Kumamoto during the post-event engineering reconnaissance. This belief was driven by several factors including the young geologic environment, alluvially deposited soils, a predominance of loose sandy soils documented in publicly available boring logs throughout the region, and the high intensity ground motions observed from the earthquake. To the surprise of many of the researchers, soil liquefaction occurred both less frequently and less severely than expected. This paper summarizes findings from our field, laboratory, and simplified analytical studies common to engineering practice to assess the lower occurrence of liquefaction. Measured in situ SPT and CPT resistance values were evaluated with current liquefaction triggering procedures. Minimally disturbed samples were subjected to cyclic triaxial testing. Furthermore, an extensive literature review on Kumamoto volcanic soils was performed. Our findings suggest that current liquefaction triggering procedures over-predict liquefaction frequency and effects in alluvially deposited volcanic soils. Volcanic soils were found to possess properties of soil crushability, high fines content, moderate plasticity, and unanticipated organic constituents. Cyclic triaxial tests confirm the high liquefaction resistance of these soils. Moving forward, geotechnical engineers should holistically consider the soil’s mineralogy and geology before relying solely on simplified liquefaction triggering procedures when evaluating volcanic soils for liquefaction.

Satellite Imagery for Rapid Detection of Liquefaction Surface Manifestations: The Case Study of Türkiye–Syria 2023 Earthquakes

“…Identified features were cross-checked using as many pre-event images as possible, aiming to exclude the presence of these features before the earthquake and disqualify possible non-earthquake-related land cover changes. Irrigated crops were especially inspected for the pre-event presence of patterns that can be a source of false positive identifications [72]. These patterns or spots in cropland that could not be validated in the pre-event timeline were excluded from mapping.…”

“…The overall distribution of liquefaction and lateral spreading sites in Amik Plain is strongly correlated to the late Holocene geomorphological conditions as can be seen in Figure 20a. Geomorphological units of Amik Plain [72] that manifested severe liquefaction phenomena were the former Amik Lake and the fluvial valley/levee of Orontes River. Despite modern-era modification of ground surface conditions by large-scale irrigation and drainage works, Holocene and historical geomorphological features can be identified through historical imagery and detailed digital terrain models (Figures 19 and 20b).…”

Liquefaction potential analysis based on standard penetration test in coastal area (Case study: Loh Buaya, Rinca Island, Indonesia)

“…Besides causing deaths, liquefaction in Palu in 2018 caused massive infrastructure damage and huge economic losses [2]. In other places, liquefaction also occurred in Wenchuan China in 2008 [3,4], Kanto Region Japan in 2011 [5], Christchurch New Zealand in 2011 [6], Kumamoto Japan in 2016 [7], Tibetan Plateau China in 2021 [8], and Central Thessaly Greece in 2021 [9].…”

Study on Inhibition Range of Liquefaction of Saturated Sand by Load Using a Shaking Table Test

“…It was found that the sand content has a great impact on the acoustic behavior of the front and back of liquefaction points [16,17,19]. Zeng [20], Heng [21], and Xenaki [22] performed experiments using multifunctional static and dynamic hydraulic shear instruments and developed a linear monotonic correlation between fine contents and pore pressure, and a nonlinear monotonic correlation between clay content and pore pressure [20][21][22][23]. Guo [24], He [25], and Yang [26] investigated the influences of initial consolidation ratio and consolidation stress on the sand strength and liquefaction of sand foundations [24][25][26].…”