AbstractsEngineering

Reliability Assessment of Load Testing for Concrete Buildings

by Amer Abu-Khajil




Institution: University of Waterloo
Department:
Year: 2015
Keywords: load testing; cyclic load test; monotonic load test; structural assessment; reinforced concrete; structural reliability; conditional probability; test load magnitude
Record ID: 2060880
Full text PDF: http://hdl.handle.net/10012/9266


Abstract

Structural rehabilitation is regularly undertaken to diagnose and repair a building during its service life; this practice ensures that buildings operate under safe and reliable conditions. Engineers generally rely on existing drawings, site investigation findings, and engineering judgement to assess the serviceability and ultimate capacity of a structure. Another approach to evaluating an existing structure is through the use of a structural load test. Under the authority of the American Concrete Institute (ACI), there are two structural load testing code provisions that exist: ACI 437.2-13 and Chapter 27 of ACI 318-14. Although both provisions provide requirements and guidelines for load testing, there are distinct differences in the test load magnitudes, loading protocols, and acceptance criteria. The primary purpose of this research was to develop an understanding of reliability-based load testing safety concepts in the context of the current provisions of ACI 437.2-13 and ACI 318 Chapter 27. Based on these findings, enhanced, diagnostic insight into the assessment of the outcomes of structural load testing was obtained. By approaching load testing from a reliability-based perspective, this research was able to provide the information necessary for practitioners to make more informed decisions regarding the diagnosis and repair of a structure. An analytical, reliability-based load testing model was developed using MATLAB. The primary objective of this model was to determine the reliability of a structural element following the performance of a successful load test. More importantly, the model was designed to accommodate practical structural assessment and load testing scenarios such as structural deterioration and occupancy change. The viability of an adjustable test load magnitude (TLM) live load factor was investigated. By adjusting the TLM live load factor, a post-load testing reliability that is consistently equal to or greater than the target reliability could be achieved.