Earthquake

INTRODUCTION

A. Background of the Study

Earthquakes are one of the disastrous events which continue to endanger human life (Li, 2015). Thousands of lives and properties were lost during earthquakes such as: Tohoku Earthquake in 2011, Bohol Earthquake in 2013, and Nepal Earthquake in 2015.

Effects of earthquakes differ depending on the location of the source. In major land masses, they often result to landslides and volcanic eruptions. Earthquakes occurring under water may result to tsunamis. In urban areas, they cause collapse of buildings.

The Philippines is very prone to seismic events because it lies along the Pacific Ring of Fire. This dangerous zone in the Pacificconsists of plates that can be likened to a jigsaw puzzle. And due to the

In 2010, National Statistics Office census states that Muntinlupa comprises of over 450,000 people, 231 schools, and 29 health facilities. Its population contributes 3.88 percent and 0.50 percent of the National Capital Region and the Philippines, respectively(Cardona et al., 2014). But more than the socio-demographic profile, Muntinlupahas been identified by PHIVOLCS to have three public schools directly located above the fault. Namely these are:Alabang Elementary School, Buli Elementary School, and Pedro E. Diaz High School. This fact imposes a danger that could cause loss of lives of students as well as school faculty and

However, the inspection was a mere visual assessment and need a “more intrusive” inspection (Tan, 2011). This lack of computation and certainty is bridged by structural analysis.

Response Spectrum Analysis (RSA) is one type of structural analysis which approximates the movement of a structure subjected to ground motion. According to Torres (2012), this method is “reasonably accurate”. It has been approved and included in the seismic provisions in the United States of America (BSSC, 2012) and in the Philippines (ASEP, 2010).

It only considers the maximum dynamic response of significant modes(NSCP, 2010). It assumes that the dynamic response can be approximated by the combination of these independent responses (Patil et al., 2013). This kind of seismic analysis eliminates the time variable and obtains the maximum structural response given by the design response spectrum of ground motion (Torres, 2012).And once the maximum structural response is obtained, the adequacy may be evaluated according to the provisions of Uniform Building Code (UBC) 1997 and NSCP