-
Reliability Analysis Of A Prestressed Concrete Beam
CHAPTER ONE -- [Total Page(s) 2]
Page 2 of 2
-
-
-
The development of structural
reliability methods during the last three to four decades have provided a
more rational basis for the design of structures in the sense that the
method facilitate a consistent basis of comparison between the
reliability of a well-tested structural design and the reliability of
new types of structures. For this reason the methods of structural
reliability have been applied increasingly in connection with the
development of new design codes (Sorenson et,al., 2002). In recent years
design codes have been continuously revised to include limit states
based on probabilistic methods. In fact the limit state design approach
has been used nearly in all the recent advances in codified design
(Ellingwood, 1996). The use of structural reliability methods for design
can lead to structures that have a more consistent level of risk
(Zimmerman et, al., 1992). Therefore, to account for the system effect
in structural assessment and design, the safety importance of structural
members must be quantified (Gharaibeh, et, al., 2001)
1.2 PROBLEM STATEMENT AND JUSTIFICATION OF STUDY
The
way in which civil engineering systems fail, the occurrence and
frequency of failure, its economics and social consequences, demonstrate
considerable differences between hypothetical and actual systems.
Induced loading, site characterization, material properties, developed
formulations and procedures and adequacy of predicted sizes and shapes
of the system and its elements are far from certain. All these factors
are subject to complex inter relationships, materials defects,
structural deficiencies, human errors and hence to varying degrees of
randomness. Reliability analysis of structures is required
as a
result of these problems. Failure of a system is assessed by its
inability to perform its intended function adequately on demand for a
period of time and under specified condition, while its antithesis, the
measure of success, is called reliability (Milton 1987).
1.3 AIM AND OBJECTIVES
1.3.1 Aim
The
aim of this research is to carry out a reliability analysisof a
prestressed concrete beam using First Order Reliability Method (FORM)
and Eurocode 2 (2004) design procedure.
1.3.2 Objectives
The objectives of this research are to:
identify the various modes of failure due to ultimate limit state of a prestressed concrete beam.
compute the probabilities of failure associated with the various modes of failure of theprestressed concrete beam.
determine the implied safety indices related to the probabilities of failure.
compute the mean safety index for each mode of failure.
establish a target safety indices associated with the modes of failure of the Prestressed concrete beam.
design a typical Prestressed concrete beam to meet a target safety level.
1.4 SCOPE OF RESEARCH
The
scope of this research was limited to the reliability analysis of a
simply supported Prestressed concrete beam in accordance with the
recommendation of Eurocode 2 (2004).
CHAPTER ONE -- [Total Page(s) 2]
Page 2 of 2
-
-
ABSRACT - [ Total Page(s): 1 ]The Reliability Analysis of a Prestressed Concrete Beam (PCB) was presented using First Order Reliability Method and Eurocode 2 procedures to carry out the analysis. The results show that the safety of the PCBin bending decreasedfrom 2.9 to 1.0 and 3.1 to 2.6 as prestress force and the depth from the extreme compressive fiber to the neutral axis of the beam increased from 20kN to 100kN and 150mm to 350mm respectively, therefore the PCB is safer at low prestress force and depth to the bottom laye ... Continue reading---
