Liquefaction Vulnerability Analysis using N-SPT Value and Grain Size Analysis on Gumbasa Irrigation Canal in the Post-Disaster Petobo Area, Sulawesi

Self Cite

The soil liquefaction disaster in Petobo, Central Sulawesi, caused massive terrain damage. With a total displacement of up to 800 meters and a total sliding area of 1.43 km2, the soil structure was deformed. The 7.5 Mw earthquake with the maximum PGA of 0.45 was causing flow-induced liquefaction with a distance from the crown to the foot of the landslide as far as 2 km. The research aims to find out how well the post-earthquake soil can withstand the potential to liquefaction if it is hit by various earthquake levels. This research will conduct several simulations to determine the soil performance against earthquakes. The empirical calculation method is carried out by referring to Idris-Boulanger to determine the liquefaction safety factor. Based on several scenarios that have been carried out, post-earthquake land can be re-liquefy when shaken by an earthquake with a certain level below the magnitude of the 7.5 Mw 2018’s Palu earthquake. There are a total of six different scenarios of earthquakes with various level of PGA. The soils still have the possibility to liquefy with the PGA of 0.20 and can be considered safe as the PGA value of 0.13. Mitigation efforts, including soil remediation, must be carried out before reconstructing phase of the Petobo irrigation canal starts.

“…If the CSR value of any soil deposit is greater than its CRR value, the soil is vulnerable to liquefaction. To get the value of CRR, the equation ( 10) to (13)…”

Section: Liquefaction Vulnerability Analysismentioning

confidence: 99%

The Effect of Various Peak Ground Acceleration Level in Petobo Irrigation Canal Area Post 2018’s Liquefaction Disaster

Sauri

Rifa’i

Hardiyatmo

2022

Self Cite

“…Previous studies on several segments of irrigation canals affected by liquefaction concluded that factors such as geological site conditions, amplitude, moment magnitude, groundwater table, and soil properties significantly affect liquefaction susceptibility. Petobo and Jono Oge at the downstream of the Sibowi segment irrigation canals tend to have shallow groundwater levels between 1.0 meter to 3.0 meters, with the dominant soil condition being sand from alluvial deposits, and this area has the potential to experience liquefaction at depths between 6-10 m with peak soil acceleration (PGA) occurring at 0.25 g in the Petobo area and 0.4 g in the Jono Oge area [7,8].…”

Section: Introductionmentioning

confidence: 99%

Liquefaction potential analysis based on standard penetration test data at irrigation canals in Sibowi Area-Central Sulawesi Province

Pucangan,

Rifa’i,

Rahardjo

2024

A phenomenon in which non-cohesive soil in saturated conditions loses its carrying capacity owing to the reduced stiffness and strength of the soil during earthquake shaking or rapid loading is called liquefaction. This occurs under the structure and can cause damage during earthquakes. In this study, we estimated the possibility of liquefaction in the main irrigation canals in the Sibowi area of Central Sulawesi Province, considering that the soil type in this area is sandy. Liquefaction analysis uses a simplified procedure using Standard Penetration Test data to obtain the Safety Factor and estimate the potential level of liquefaction using the Liquid Potential Index (LPI) method. According to the analysis, with the 7.5 Mw earthquake and groundwater levels observed, most of the soil layer below the irrigation canals still has liquefaction potential at 15 m to 19.5 m. The LPI result that 5 (five) out of 10 (ten) boreholes have the potential for liquefaction in low to moderate categories, and the boreholes that have liquefaction potential have groundwater depths between 14 and 16 m.

“…Thus, knowledge of the liquefaction potential of alluvial deposits is necessary to reduce the risk associated with earthquake-induced liquefaction phenomena in Palu City. Some previous studies have been conducted to analyze liquefaction phenomena, especially in flow liquefaction areas using SPT [3,4] and Vs methods [5]. This paper presents the results of liquefaction potential analysis based on the CPT method in some locations around the city where sand boiling occurred during the 2018 earthquake.…”

Section: Introductionmentioning

confidence: 99%

Liquefaction potential analysis for Palu City based on CPT method

Tohari¹,

Soebowo²,

Wibawa³

et al. 2023

During the 28 September 2018 Palu-Donggala earthquake, liquefaction was also a prominent hazard causing significant damage to buildings and infrastructures in Palu City. To mitigate such a hazard in Palu City, knowledge of the depth of the liquified soil layer is necessary. This paper presents the results of CPT-based liquefaction potential analysis in some locations around the city where sand boiling and ground settlement occurred. The analysis shows that liquefaction occurs at various depths less than 15 m and may induce ground settlement up a few centimeters. In the Palu-Koro Fault zone, the liquified sand layer is likely thicker than in other locations. Consequently, the total ground settlement is higher than in other locations The results of this study suggest that the liquefaction potential should be accounted for in the development of Palu City to reduce future earthquake risk.