Progressive collapse analysis of steel transmission towers subjected to earthquakes with pulse effect using applied element method | |
| Author | Jayasinghe, Rajasinghege Mahendra Deshapriya |
| Call Number | AIT Thesis no.ST-24-26 |
| Subject(s) | Electric lines--Poles and towers--Earthquake effects Steel, Structural--Earthquake effects Finite element method--Data processing |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering in Structural Engineering |
| Publisher | Asian Institute of Technology |
| Abstract | Steel electric transmission towers are crucial for supporting overhead powerlines and are classified as lifeline structures. The most commonly used type of steel electric transmission towers are suspension towers. These steel structures are generally considered safe during seismic events. However, collapses have been observed under a specific ground motion effect known as a pulse. Progressive collapse of transmission towers can occur by sudden natural hazards like earthquakes, particularly when influenced by pulse effects. This causes localized damage to structural elements, such as load-bearing members, and leads to the failure of the entire structure or a significant portion of it. Pulse effects are especially critical, being characterized by their short duration, large amplitude, and rapid release of seismic energy. These intense forces can cause transmission towers to fail, impacting the whole lifeline and may lead to a total blackout.This research aims to examine the progressive collapse behavior of steel electric transmission towers under pulse and non-pulse conditions of identical ground motions. The Applied Element Method (ELS software) is used for numerical analysis on both wire-loaded and non-wire-loaded configurations of suspension-type towers subjected to three ground motions.To extract pulse from the three ground motions, continuous wavelet transform analysis is employed. Only the significant pulse was extracted.The results indicate that both wire-loaded and non-wire-loaded towers under pulse conditions collapsed during the pulse duration. However, without pulse conditions both towers only experienced minor damage without collapse. Non-wire-loaded tower required peak ground acceleration (PGA) with pulse to collapse compared to wire loaded tower. Most of the higher displacements and elements failed at tower height between 37.05 m to 42.55 m. It’s also identified as the critical location of both tower configurations under pulse effects, with failure primarily due to the buckling effect. When wire-loaded and non-wire-loaded towers collapse under pulse conditions, the total energy-time graphs observe a significant release of energy (sudden sharp peak during the collapse), while under non-pulse conditions for both towers, the energy curves remain constant towards the end. |
| Year | 2024 |
| Type | Thesis |
| School | School of Engineering and Technology |
| Department | Department of Civil and Infrastucture Engineering (DCIE) |
| Academic Program/FoS | Structural Engineering (STE) /Former Name = Structural Engineering and Construction (ST) |
| Chairperson(s) | Krishna, Chaitanya |
| Examination Committee(s) | Anwar, Naveed;Thanakorn Pheeraphan |
| Scholarship Donor(s) | Computer and Structures Inc.(CSI), USA;AIT Scholarship |
| Degree | Thesis (M. Eng.) - Asian Institute of Technology, 2024 |