Reliability Analysis of Earthquake-Induced Liquefaction in Manila using Monte Carlo Simulation

Earthquakes or seismic events cause several disturbances in the ground which can harm or damage the structural stability and could turn fatal. Liquefaction causes a sudden movement shift that is out of sync with the rest of the structure. This might cause several structural damages to the property leading to casualties. In the Philippine geographical context, the West Valley Fault which traverses Metro Manila is a seismic threat capable of producing a maximum magnitude of 7.2. This study aims to assess the probability of liquefaction in Farnecio St., Quaipo, Manila as well as the determination whether the structures present will suffer from critical failure or not. Probabilistic Seismic Hazard Analysis and Monte Carlo Simulation were used to determine the seismic hazard. Recorded earthquake history from the Philippine Institute of Volcanology and Seismology was used as part of the seismic analysis. The seismic hazard analysis shows that a magnitude 5.3 earthquake has a 44.44 % probability of occurrence within the 10-to-20-kilometer distance from the seismic source. A peak ground acceleration of 0.458g and 0.548g was also determined for return periods of 500 and 2500 years for which a Uniform Hazard Response Spectrum was generated. The probability of damage for 2% in 50 years and 10% in 50 years is 39.63% and 30.41%, respectively.