scholarly journals Reliability basis of load and resistance factors for reinforced concrete design

1978 ◽  
Author(s):  
Bruce Ellingwood
Keyword(s):  
Reinforced Concrete ◽  
Resistance Factors ◽  
Load And Resistance Factors

Load and Resistance Factors for Progressive Collapse Resistance Design of Reinforced Concrete Building Structures

2011 ◽  
Vol 255-260 ◽  
pp. 338-344 ◽  
Author(s):  
Ying Wang ◽  
Feng Lin ◽  
Xiang Lin Gu
Keyword(s):  
Reinforced Concrete ◽  
Progressive Collapse ◽  
Building Structures ◽  
Safety Factors ◽  
Ultimate State ◽  
Resistance Factors ◽  
Collapse Resistance ◽  
Load And Resistance Factors ◽  
Load Effects ◽  
Partial Safety Factors

Due to the absence of provision for the load and resistance factors in design codes in China, designers often quote the provisions which are given in criterion or guidance of other countries such as USA. However, the partial safety factors of the load are various in different criterions. Based on the reliability theory, the load and resistance factors for progressive collapse resistance design of building structures were determined in this study. Firstly the simplified format of design expression in the ultimate state was obtained according to the expression in routine structural design. Then the failure probability of a structure during design reference period was taken as the sum of the probability of all incompatible failure events in this period, and the objective reliability index of the structure could be obtained. Finally using trial-and-error procedure and JC method, reliability analysis was performed for structural members to obtain the partial safety factors of load effects and resistance and the coefficient for combination value of load effects in design expression in the ultimate state. In this paper the load and resistance factors for progressive collapse resistance design of reinforced concrete structures subjected to blast was calculated as an example, and the recommendation values were given for the application at last.

Calibration of the Ontario Highway Bridge Design Code 1991 edition

1994 ◽  
Vol 21 (1) ◽  
pp. 25-35 ◽  
Author(s):  
Andrzej S. Nowak ◽  
Hid N. Grouni
Keyword(s):  
Reinforced Concrete ◽  
Reliability Analysis ◽  
Prestressed Concrete ◽  
Highway Bridge ◽  
Live Load ◽  
Design Code ◽  
Reliability Indices ◽  
Resistance Factors ◽  
Load And Resistance Factors ◽  
Selection Of

The paper describes the calculation of load and resistance factors for the Ontario Highway Bridge Design Code (OHBDC) 1991 edition. The work involved the development of load and resistance models, the selection of the reliability analysis method, and the calculation of the reliability indices. The statistical models for load and resistance are reviewed. The considered load components include dead load, live load, and dynamic load. Resistance models are developed for girder bridges (steel, reinforced concrete, and prestressed concrete). A reliability analysis is performed for selected representative structures. Reliability indices are calculated using an iterative procedure. The calculations are performed for bridge girders designed using OHBDC 1983 edition. The resulting reliability indices are between 3 and 4 for steel girders and reinforced concrete T-beams, and between 3.5 and 5 for prestressed concrete girders. Lower values are observed for shorter spans (up to 30–40 m). The acceptance criterion in the selection of load and resistance factors is closeness to the target reliability level. The analysis confirmed the need to increase the design live load for shorter spans. Partial resistance factors are considered for steel and concrete. The criteria for the evaluation of existing bridges are based on the reliability analysis and economic considerations. Key words: bridge code, calibration, load factor, resistance factor, reliability index.

Calibration of design code for buried structures

2001 ◽  
Vol 28 (4) ◽  
pp. 574-582 ◽  
Author(s):  
Andrzej S Nowak ◽  
Chan-Hee Park ◽  
Peter Ojala
Keyword(s):  
Reinforced Concrete ◽  
Reliability Index ◽  
Water Pressure ◽  
Earth Pressure ◽  
Highway Bridges ◽  
Design Code ◽  
Buried Structures ◽  
Reliability Indices ◽  
Resistance Factors ◽  
Load And Resistance Factors

The reliability-based calibration procedures were applied to develop load and resistance factors for the Ontario Highway Bridge Design Code (1979, 1983, and 1991) and recently the Canadian Highway Bridges Design Code (2000). However, the load components for buried structures were not considered. The development of a statistical model for earth pressure requires a special approach. Therefore, this paper deals with the reliability-based calibration of the design code for buried (cut-and-cover) structures. A typical running structure consists of reinforced concrete walls forming a rectangular box section, while an underground station may have a one- to six-cell box. The major load components include earth pressure, water pressure and weight of the concrete. Other load components such as live load are relatively small. Statistical parameters are derived for representative structures and structural systems. The correlation between load components is estimated based on the available field data. Structural performance is measured in terms of the reliability index. Reliability indices are calculated for a representative spectrum of running structures and stations. In general, the reliability indices for existing buried structures are higher than those for bridges or buildings. The target reliability index has been selected on the basis of calculated reliability indices, comparison with other structures, and cost analysis (consequences of failure). The optimum load and resistance factors are calculated and recommended for the design code to achieve a uniform safety level.Key words: buried structure, code calibration, load models, reinforced concrete, reliability analysis, resistance models.

scholarly journals RETRACTED: Safety Index Evaluation and Calibration of Load and Resistance Factors for Concrete Beams Under the Simultaneous Effects of Bending, Shear and Torsion

2017 ◽  
Vol 7 (4) ◽  
pp. 1820-1825
Author(s):  
A. Azhari ◽  
M. R. Mesbahi
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beams ◽  
Reinforced Concrete Beams ◽  
Safety Index ◽  
Resistance Factors ◽  
Index Evaluation ◽  
Load And Resistance Factors ◽  
Article 5 ◽  
Published Paper

This article has been retracted at the request of the Editor-in-Chief due to extended similarites with a previously published paper (in Persian).The previously published paper is:F. Jafari, J. Akbari, A. Jahanpur, "Evaluation of Safety Index and Calibration of Load and Resistance Factors for Reinforced Concrete Beams under Bending, Shear and Torsion Demands", Journal of Structural and Contruction Engineering, Article 5, Vol. 3, No. 4, pp. 49-64, 2017 (in Persian)The authors of this paper failed to provide any reasoning regarding the case. 

Comparative Review of the Established UHB Assessment Methods for Offshore Pipelines

2015 ◽  
Author(s):  
Sajith Kumar ◽  
Daniel Smith ◽  
Hooman Jafari
Keyword(s):  
Survey Data ◽  
Structural Reliability ◽  
Load Resistance ◽  
Design Parameters ◽  
Operational Parameters ◽  
Resistance Factors ◽  
Upheaval Buckling ◽  
Variation Of Parameters ◽  
Comparative Review ◽  
Load And Resistance Factors

Out of straightness upheaval buckling (OOS UHB) assessment considers the pipeline design and operational parameters, post-lay survey data and the properties of back-fill and rock in order to determine load and resistance factors that are applied. The factors allow for the natural variation of all parameters and are ultimately used to determine the download requirements along the route of a pipeline that is susceptible to UHB. Two methods are most commonly used in OOS UHB assessments. The structural reliability analysis (SRA) method is the most established and explicitly considers the variation of parameters in a Monte-Carlo simulation, enabling load and resistance factors to be calculated with a defined reliability level. A more recently developed methodology is documented in DNV-RP-F110 and provides a unified approach to the calculation of safety factors. The approach was calibrated using structural reliability based methods, undertaken with target reliability levels that are compliant with DNV-OS-F101. This paper presents a review of two key components of OOS UHB assessments. These components are the accuracy of post-lay survey data and the load resistance factor calculation method. These components are reviewed in the context of SRA and DNV-RP-F110 based assessments for a range of pipeline sizes, and ranges of soil and operational parameters. This enables characterisation of the differences between the two methodologies for ranges of design parameters that represent the majority of in-field flowlines that are installed in the United kingdom Continental Shelf (UKCS). SRA and DNV-RP-F110 derived load and resistance factors are compared and the effect of survey data smoothing upon rock-dump requirements is also discussed.

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