Seismic vulnerability assessment of a historical structure: A case study of El Deposito Waterworks System

• Main Authors: Alberto, Bea S., Apacible, Patrick Anthony M., Pacayra, April Oilec Deanielle B., See, April Oilec Deanielle J.
• Format: text
• Language: English
• Published: Animo Repository 2018
• Subjects: Structural engineering; Tunnels > Design and construction; El Deposito Waterworks System; Civil Engineering
• Online Access: https://animorepository.dlsu.edu.ph/etd_bachelors/9085
• Institution: De La Salle University

Due to old age and the materials used during construction, a historical structure is deemed vulnerable to damages brought about by natural hazards. Being located within the Pacific ring of fire, the Philippines experiences numerous earthquakes and may pose as a significant threat to a historical structure. With the plan of the National Historical Commission of the Philippines to convert an underground tunnel into a museum, a seismic vulnerability assessment of the historical structure-- El Deposito Waterworks System in Pinaglabanan, San Juan City, was conducted, considering a possibility of an earthquake generated from the West Valley fault. The peak ground acceleration (PGA) and the response spectrum obtained using probabilistic seismic hazard analysis (PSHA) was used as input to a software to produce the time history for the nonlinear time history analysis, by matching the response spectrum with the 1978 Great Thessaloniki Earthquake. Finite element analysis was conducted for modelling the tunnel, with pinned supports and horizontal soil springs. Shear stresses for every scale of PGA from 0.1g to 0.4g from the analysis were compared with the shear capacity of the material comprising the structure based from Ampad, Castillo, Odiamar, Tingco and Garciano (2017) which is 1.71 MPa and the World of Engineering Organizations (2011) which is 0.1 MPa. Results showed that the shear stresses did not exceed the shear capacity, as the maximum shear stress experienced by an element after subjecting the structure to dead loads and an earthquake load of 0.4g PGA was found to be 0.08341 MPa. SInce failure did not occur upon application of a 0.4g PGA earthquake, the time history was further scaled to 2.0g PGA, resulting to a maximum shear stress of 0.9108 MPa, which did not exceed the shear capacity. The shear maximum stresses are found to have a direct relationship with the peak ground acceleration of the earthquake load, and which occur at the intersection of the arch and the inner wall of the tunnel while maximum displacement