Land Damage Mapping and Liquefaction Potential Analysis of Soils from the Epicentral Region of 2017 Pohang Mw 5.4 Earthquake, South Korea

Abstract

Studies on earthquake-induced liquefaction and identification of source unit for causing liquefaction have been a major concern in sustainable land use development especially in low to moderate seismic areas. During the 2017 M w 5.4 Pohang earthquake, widespread liquefaction was reported around the Heunghae basin, which was the first ever reported case of liquefaction in the modern seismic history of Korea. The epicentral area is one of the major industrial hubs along the SE Korean Peninsula with no detailed liquefaction hazard map. The purpose of this study was to determine the land damage classification on the basis of surface manifestation of liquefaction features and carry out detailed liquefaction potential analysis to delineate the depth of liquefiable soil. This will eventually support developing a liquefaction hazard zonation map and sustainable development of infrastructure to minimize earthquake damages. In this present study, the southern part of the Heunghae basin, which has more field evidences of liquefaction than the northern part, was taken for detailed liquefaction analysis. From the detailed analysis, it was observed that the soils from 1.5 to 15 m depth with the probability of liquefaction varying from 2 to 20 are prone to liquefaction. On the basis of land damage pattern, the epicentral area falls in orange to red zone, which means the necessity of further detailed liquefaction analysis. This study urges more detailed liquefaction zonation should be carried out for the epicentral area and liquefaction hazard should be included in the multi-hazard map in the future for the sustainable land use planning.

Site response and liquefaction hazard analysis of Hawassa town, Main Ethiopian Rift

“…Frontiers in Built Environment frontiersin.org the particle size, shape and gradation of soil to evaluate the susceptibility of liquefaction, while some research has reported the age of the deposit and depth of the groundwater level for the evaluation of susceptibility to liquefaction (Youd and Hoose, 1977;Youd and Perkins, 1987;Kavazanjian et al, 1997;Satyam and Towhata, 2016;Naik et al, 2020;Subedi and Acharya, 2022).…”

“…Generally, the liquefaction potential is predicted where there is possibility of increase in pore water pressure and loss of shear strength occurred in a soil. Hence, the liquefaction potential was predictable at site 1 (Figure 10A) due to increase in pore water pressure and loss Frontiers in Built Environment frontiersin.org of shear strength occurred in a soil (Ganapathy and Rajawat, 2012;Setiawan and Jaksa, 2018;Subedi and Acharya, 2022), but the soil at site 2 as shown in Figure 10B and site 3 at Figure 10C, site 4 at Figure 11A and site 5 at Figure 11B was not predictable as they had no chance of pore water pressure and loss of shear strength for the given ground motion (Naik et al, 2020). Thus, the result of this study was supported by the findings of Ji et al (2021).…”

Potential Study of Liquefaction in the Downstream Area of Jono Oge-Paneki River, Central Sulawesi

“…Equation ( 17) used if 2 > 𝐹𝑆 𝑙𝑖𝑞 > 𝐹 𝛼 , due to 𝐹𝑆 𝑙𝑖𝑞 > 2 then 𝛾 𝑚𝑎𝑥 = 0. And for equation (19) 𝛾 𝑚𝑎𝑥 = 𝛾 𝑙𝑖𝑚 if 𝐹𝑆 𝑙𝑖𝑞 ≤ 𝐹 𝛼 , where 𝛾 𝑙𝑖𝑚 is limiting shear strain, 𝐹 𝛼 is an additional parameter factor of safety and 𝐹𝑆 𝑙𝑖𝑞 is the FS against triggering of liquefaction. A large number of lateral spreading occurs is the sum of each layer that occurs spreading in meters.…”

“…Another method used to determine reconsolidation settlement is to consider shear deformation. According to [19], the recommended relationships can be reasonably approximated by using this equation (20) (21)…”

Development of a Probabilistic Seismic Performance Assessment Model of Slope Using Machine Learning Methods

“…However, since the start of monitoring and measuring earthquake motions in 1978, earthquakes in Korea with a moment magnitude of 2.0 or higher have occurred 20 times per year until 1998, but this frequency has increased to an average of 48 times per year during the period between 1998 and 2015 [3]. Furthermore, Korea has experienced two strong earthquakes, one in Gyeongju in 2016 and the other in Pohang in 2017, raising concerns over safety during earthquakes near major facilities [1,[4][5][6].…”