Analysis of Hurricane Maria’s Impact on the Arecibo Telescope

Abstract

The Arecibo Telescope in Puerto Rico collapsed on December 1, 2020. After the incident, Thornton Tomasetti Inc. (TT) was engaged by the Florida Space Institute to conduct a forensic investigation of the root cause of the collapse. An essential focus of the investigation was the impact of wind loads and particularly of Hurricane Maria in 2017, the strongest hurricane that the telescope had experienced in its service life. Computational fluid dynamic (CFD) analysis can be used to simulate the response of unusual structures’ to wind loads; however, it can be computationally expensive for complex structures or winds with long durations. Conducting this type of analysis may be feasible by involving high-performance computing systems. However, given the scope of the investigation, as well as the limited time and budget, performing such a sophisticated CFD analysis of the telescope subjected to the full hurricane time history was infeasible. TT adopted a cost-effective method to simulate the wind loads on the telescope during Hurricane Maria and apply those forces to a structural analysis model. The technique uses a combination of CFD analysis, previous wind tunnel test results, and wind speed records. A CFD model of the telescope was used to generate wind forces at a constant wind speed and was validated by previous wind tunnel tests on a physical model of the telescope. The validation shows that the CFD analysis can adequately depict the wind tunnel test results and that the wind forces can be scaled based on wind speeds. The wind forces from CFD analysis were then scaled to time-varying forces based on the on-site measured wind speeds during Hurricane Maria. The time-varying forces were subsequently applied to a finite element (FE) model of the telescope to evaluate its dynamic response during Hurricane Maria. This paper provides an in-depth description of each analysis step, validation of the wind force scaling method, and the telescope’s response to Hurricane Maria. The results show that the forces in the cables supporting the telescope increased 14% during Hurricane Maria.