Developing a resilience index for the pile-supported piers of the port of Batangas under tsunami load

• Main Author: Telan, Jon Arnel S.
• Format: text
• Language: English
• Published: Animo Repository 2020
• Subjects: Piers—Philippines—Testing; Piers—Environmental testing—Philippines; Structural analysis (Engineering); Piling (Civil engineering); Strength of materials; Tsunami hazard zones—Philippines; Civil Engineering
• Online Access: https://animorepository.dlsu.edu.ph/etd_masteral/6359; https://animorepository.dlsu.edu.ph/context/etd_masteral/article/13403/viewcontent/Telan_JonArnel_11772530_Developing_a_resilience_index_for_the_pile_supported_piers_of_the_port_of_Batangas_under_tsunami_load_2_Redacted.pdf
• Institution: De La Salle University

Port system has a valuable role in providing services mainly human public transportation and trade of goods which play major economic impact at different levels. One of the most significant port terminals is the ro-ro(roll-on/roll-off) which serves as the receiving/dispensing end for ships or vessels carrying cargoes and vehicles. The roll-on/roll-off transport system has made huge economic impact in the Philippines benefitting not only the direct passengers, businesses, and the port organization but the households living nearby the terminals. It mainly uses piers and wharves as berthing structures. The piers are extensions of the ro-ro terminals against the shoreline to provide smooth berthing of ships without any obstructions and disturbances. However, its configuration in terms of location and structural components has attracted different hazards which may cause massive failures and damages particularly to piles. This may heavily result to discontinuity of the whole port operation as there will be no available berthing structure for ships. The exposure of the piers to environmental hazards, including earthquake and tsunami, has been very critical initiating different disaster-related studies. Tsunami, which is often due to offshore seismic activities, produces devastating wave forces demanding a need to conduct a resilience study in pile-supported piers involving its ability to withstand failure and recover back to full performance. Thus, this paper focused on measuring the structural resilience of the pile-supported piers of port of Batangas under tsunami wave loads at different variations of wave height and water depth. A wave flume experiment was conducted to generate solitary waves where wave heights and velocities at specific points were recorded using wave gauges (WG) and electromagnetic current meter (ECM), respectively. Using these parameters, drag forces were calculated which were applied as load inputs in the structural modeling. ETABS 2016 was the software used to accurately model the pile-supported piers. Other significant data including structural plans, soil report, and bathymetric map were requested from PPA. Pushover analysis was then conducted to the piers using the same software focusing on the non-linear performance of the piles at the longitudinal and transverse directions. The analysis provided the base shear vs displacement curves at different failure modes to compute for the robustness index at different drag force cases. Results showed that robustness index generally ranges from 0.972 to 0 at the longitudinal direction and 0.985 to 0 at the transverse direction as the wave height increases from 2 m to 8 m. The recovery behavior was based on an interview to PPA Port Management Office (PMO) of Batangas resulting to recovery rates of 39 piles in 25 days for demolition works and 39 piles in 103 days for pile replacement. A pre-disaster assessment was also performed to gauge the starting performance of the structure which resulted to an index of 1.0. Combining these indices using the concept of resilience triangle, the resilience index generally ranges from 1.000 to 0.403 at both longitudinal and transverse directions. Values were used to categorize the structural resilience as low, medium, or high.