Liquefaction Potential Based on Swedish Weight Sounding Test in Langaleso Village Sigy Regency

The ground movement caused by the
liquefaction phenomenon is one of the disasters that has
claimed many lives and material losses in the devastating
earthquake that occurred in the cities of Palu, Sigi, and
Donggala on September 28, 2018. The village of
Langaleso was certainly also affected, resulting in damage
to existing facilities and infrastructure. This research
investigations the characteristics of the soil and the
potential for liquefaction in the soil that is suspected to
have occurred. This research was conducted by using the
Swedish Weight Sounding test and laboratory testing in
the form of particle size analysis and Atterberg
boundaries. Data analysis was performed by using the
values of Cyclic Stress Ratio (CSR) and Cyclic Resistance
Ratio (CRR), safety factor (FS), Liquefaction Potential
Index (LPI), and Probability of Liquefaction (PL) . The
study was carried out at 10 test points with a
groundwater level of 0.68 meters sourced from JICA in
2020. The results of laboratory testing showed that the
soil types range from loamy sand to silty sand with poor
grades. While the Swedish Weight Sounding test obtained
Nsw values between 0.00 – 454.55 n/m, qa values ranged
from 0.00 – 393.64 kN/m2 and qu values ranged from 2.22
– 385.91 kN/m2 . It can be concluded that all test points
have the potential for liquefaction to occur, where
liquefaction occurs at varying depths at a minimum depth
of less than 10 meters with an earthquake acceleration
limit value (amax ) of 0.15 g and an earthquake magnitude
of 5 Mw.