The Ontario bridge code—Development and implementation

1984 ◽  
Vol 11 (4) ◽  
pp. 824-832
Author(s):  
R. A. Dorton
Keyword(s):  
Highway Bridges ◽  
Safety Index ◽  
Design Code ◽  
Limit States ◽  
Safety Level ◽  
New Development ◽  
Live Loads ◽  
Index Value ◽  
Correct Understanding ◽  
Short Time

The Ontario Highway Bridge Design Code was first issued in 1979 and has since been used for the design and evaluation of most bridges in Ontario. The code is in metric SI units, written in a limit states format, and calibrated to a target safety index value of 3.5. It has produced bridges with a more consistent safety level and capable of carrying design live loads twice those previously prescribed. Feedback from users was obtained and their concerns considered in formulating the provisions of the seeond edition in 1983. New bridge codes can be written in a short time and implemented most readily within a relatively small jurisdiction having control of all highways, bridges, and vehicles. Communications between the writers and potential users are important throughout the preparation and implementation phases. It is essential that a commentary volume be issued with a code to ensure correct understanding and interpretation of new provisions. Computer programs should be available, incorporating the code technology before the use of a new code becomes mandatory. Future code needs and likely areas of new development are outlined in the paper. Key words: calibration, codes, computer systems, highway bridges, loadings, safety, structures.

Reliability assessment in highway bridge design

2002 ◽  
Vol 29 (5) ◽  
pp. 799-805 ◽  
Author(s):  
M S Cheung ◽  
W C Li
Keyword(s):  
Reliability Assessment ◽  
Highway Bridges ◽  
Highway Bridge ◽  
Design Code ◽  
Bridge Design ◽  
Limit States ◽  
Safety Level ◽  
Reliability Design ◽  
Finite Strip Method ◽  
Standard Design

The current practice of highway bridge design in Canada is based on limit states design. Ideally, by means of the properly calibrated load and resistance factors specified in the applicable design code, limit states design will yield a consistent and uniform safety level for all designed bridge structures. Some factors neglected in the standard design procedures, however, may have unexpected effects on the reliability of a particular design. In this case, to follow a design code exactly may still lead to a certain degree of underdesign or overdesign. Therefore, the reliability assessment is recommended for each particular design, and a simulation-based approach for this assessment is proposed in this study. Examples are presented to support the afore-mentioned recommendation.Key words: highway bridges, reliability, design code, simulation, finite strip method.

Calibration of the Ontario Bridge Design Code 1983 edition

1984 ◽  
Vol 11 (4) ◽  
pp. 760-770 ◽  
Author(s):  
Hid N. Grouni ◽  
Andrzej S. Nowak
Keyword(s):  
Reliability Index ◽  
Calibration Procedure ◽  
Design Code ◽  
Bridge Design ◽  
Limit States ◽  
Safety Level ◽  
Acceptance Criterion ◽  
Resistance Factors ◽  
Concrete Girders ◽  
Load And Resistance Factors

The paper summarizes the calibration procedure used to calculate load and resistance factors for the Ontario Bridge Design Code 1983 edition. The limit states considered include serviceability and ultimate limit states during service and in construction. The acceptance criterion is closeness to a predetermined target safety level. Safety is measured in terms of a reliability index. The results of calibration are discussed for composite steel–concrete girders, pretensioned concrete girders, post-tensioned concrete decks, and timber decks. The analysis of construction design criteria is demonstrated on segmental bridges. Key words: code calibration, bridges, reliability index, load and resistance factors, limit states.

Cluster analysis as a tool in the classification of structures for safety differentiation

1988 ◽  
Vol 15 (4) ◽  
pp. 601-608
Author(s):  
Carlos Ferregut
Keyword(s):  
Cluster Analysis ◽  
Highway Bridges ◽  
Structural Type ◽  
Limit States ◽  
Safety Level ◽  
Code Calibration ◽  
New Concepts ◽  
Safety Parameters ◽  
The Difference ◽  
Selection Of

Different structures and different structural members should reasonably be assigned different levels of reliability to obtain optimum structural performance. This differential assignment of reliabilities or safety parameters is called "safety level differentiation." Up to the present, no simple practical rationale is available for the selection of safety levels. This paper presents a methodology for the selection of safety levels. Cluster analysis is suggested as a tool in the calibration of limit states design codes. The technique may be used to develop importance factors for the design loadings and resistances, reflecting the difference in consequences of failure. The cluster analysis serves to classify a structure according to various attributes that together reflect its social and economic importance. For code specification purposes, it is fundamental to identify which structures in a set are similar, because it facilitates the specification of a single set of code parameters for each structural type, and permits a more rational selection of importance factors. The acceptable number of structural types and the effect of weighing the attributes are also discussed. Some of the new concepts are illustrated using a sample of highway bridges in southwestern Ontario. Key words: safety differentiation, reliability, cluster analysis, code calibration, bridge classification.

scholarly journals Comparison of reliability evaluation methods between China and Canada standards for wood structures featuring duration of load

2020 ◽  
Vol 66 (1) ◽  
Author(s):  
Qiongyao Wu ◽  
Shuang Niu ◽  
Enchun Zhu
Keyword(s):  
Reliability Analysis ◽  
Analysis Method ◽  
Safety Level ◽  
Wood Structures ◽  
Load Effect ◽  
Key Factor ◽  
Live Loads ◽  
High Level ◽  
Partial Factor ◽  
Duration Of Load

Abstract Duration of load (DOL) is a key factor in design of wood structures, which makes the reliability analysis of wood structures more complicated. The importance of DOL is widely recognized, yet the methods and models through which it is incorporated into design codes vary substantially by country/region. Few investigations of the effect of different model assumptions of DOL and other random variables on the results of reliability analysis of wood structures can be found. In this paper, comparisons are made on the reliability analysis methods that underlie the China and the Canada standards for design of wood structures. Main characteristics of these two methods, especially the way how DOL is treated are investigated. Reliability analysis was carried out with the two methods employing the same set of material properties and load parameters. The resulted relationships between reliability index β and resistance partial factor γR* (the β–γR* curves) for four load combinations are compared to study the safety level indicated by the two methods. The comparison shows that the damage accumulation model (Foschi–Yao model) in the Canada analysis method is highly dependent on the type and duration of load, resulting in more conservative design than the China analysis method in loading cases dominated by dead load, but less conservative design in cases of high level of live loads. The characteristics of the load effect term of the performance function are also found to make considerable difference in reliability levels between the two methods. This study aims to provide references for researchers and standard developers in the field of wood structures.

A Framework to Evaluate the Benefit of Seismic Upgrading

2019 ◽  
Vol 35 (2) ◽  
pp. 1045-1051 ◽  
Author(s):  
Clotaire Michel ◽  
Blaise Duvernay ◽  
Ehrfried Kölz ◽  
Navid Jamali ◽  
Pierino Lestuzzi
Keyword(s):  
Existing Buildings ◽  
Design Code ◽  
Absolute Level ◽  
Safety Level ◽  
Seismic Code ◽  
Practical Applications ◽  
The Absolute ◽  
Cost Efficient ◽  
The One ◽  
Level Of Risk

The framework to evaluate the benefit of seismic upgrading of Galanis et al. (2018) is compared to that present in the Swiss seismic code for existing buildings since 2004, updated in 2017. To illustrate the comparison, the example building of Galanis et al. (2018) in Zurich is analyzed following the Swiss code. It is shown that the concept of Degree of Seismic Upgrade is not relevant for practical applications. More generally, the approach of Galanis et al. (2018) would be more suited to a risk-based framework (like the Swiss code) than to a performance-based framework like the one they followed. For existing buildings, we claim that it is appropriate to define the retrofitting strategy based on the absolute level of risk, whereas targeting the safety level of the design code is rarely cost-efficient.

scholarly journals SMART SECURITY AND SAFETY INDEX MEASUREMENT: A CASE STUDY IN BANDUNG INDONESIA

2019 ◽  
Vol 7 (5) ◽  
pp. 141-149
Author(s):  
Indrawati ◽  
Tania Dayarani ◽  
Husni Amani
Keyword(s):  
Mixed Method ◽  
Smart City ◽  
Safety Index ◽  
Huge Number ◽  
Safety Level ◽  
Index Measurement ◽  
The World ◽  
Index Level ◽  
The City

Purpose: Nowadays, the development of technology is very fast and increasingly sophisticated; no doubt all the problems in a city can be solved quickly and well. Hence, facing a huge number of the urban population, the city must adopt the strategy of smart city so that the standard of life can be improved. Some of the cities in the world have applied the concept of smart city. One of the dimensions in smart city concept is smart security and safety. This study aims to know the indicators and index level of smart security and safety in Bandung city of Indonesia. This research explores the indicators and measures the index level of smart security and safety in Bandung.  Methodology: The research method characteristics applied in this study is the exploratory sequential mixed method. Main Findings: This study finds that there are 20 indicators to measure the index level of smart security and safety. The smart security and safety level of Bandung city is 72% which is considered that on average the measured indicators are already good enough and satisfied, but there are some indicators that should be improved. The variable that should be improved is variable of Awareness and Understanding which has score of 49%. Implications/Applications: It is suggested by this study that the socialization of smart security and safety program such as Panic Button Application, LAPOR! The website should be more effective through making socialization more targeted and real.

scholarly journals Reliability-Based Safety Evaluation of the BISTOON Historic Masonry Arch Bridge

2020 ◽  
Vol 30 (1) ◽  
pp. 87-110 ◽  
Author(s):  
Majid Pouraminian ◽  
Somayyeh Pourbakhshian ◽  
Ehsan Noroozinejad Farsangi ◽  
Sevil Berenji ◽  
Salman Keyani Borujeni ◽  
...  
Keyword(s):  
Probabilistic Analysis ◽  
Safety Evaluation ◽  
Random Variables ◽  
Load Resistance ◽  
Maximum Tensile Stress ◽  
Safety Index ◽  
Limit States ◽  
Masonry Arch ◽  
Arch Bridge ◽  
Historic Masonry

AbstractThis research examines the probabilistic safety assessment of the historic BISTOON arch bridge. Probabilistic analysis based on the Load-Resistance model was performed. The evaluation of implicit functions of load and resistance was performed by the finite element method, and the Monte-Carlo approach was used for experiment simulation. The sampling method used was Latin Hypercube. Four random variables were considered including modulus of elasticity of brick and infilled materials and the specific mass of brick and infilled materials. The normal distribution was used to express the statistical properties of the random variables. The coefficient of variation was defined as 10%. Linear behavior was assumed for the bridge materials. Three output parameters of maximum bridge displacement, maximum tensile stress, and minimum compressive stress were assigned as structural limit states. A sensitivity analysis for probabilistic analysis was performed using the Spearman ranking method. The results showed that the sensitivity of output parameters to infilled density changes is high. The results also indicated that the system probability of failure is equal to p fsystem =1.55 × 10−3. The bridge safety index value obtained is βt = 2.96, which is lower than the recommended target safety index. The required safety parameters for the bridge have not been met and the bridge is at the risk of failure.

scholarly journals Study on Evaluation Models of Highway Safety Based on Catastrophe Theory

2014 ◽  
Vol 2014 ◽  
pp. 1-8
Author(s):  
Hezheng Bi ◽  
Linjun Lu ◽  
Jian Lu ◽  
Chen Wang
Keyword(s):  
Catastrophe Theory ◽  
Evaluation Method ◽  
Safety Evaluation ◽  
Mortality Rates ◽  
Video Data ◽  
Safety Index ◽  
Safety Level ◽  
Relative Safety ◽  
Highly Correlated ◽  
General Safety

Evaluating safety performance of first-class highways in China is important due to their high mortality rates. Traditional models for statistical crash prediction and traffic conflict techniques require long periods of data collection which is time-consuming and labor-intensive. This paper introduces a safety evaluation method based on catastrophe theory for highways in China. The method firstly divides the highway into multiple road sections and uses video-based road detection (VRD) system to collect video data of existing road conditions. Then, experienced drivers and experts are invited to watch the collected videos to establish a multilayer safety index system and assign values to bottom indexes. By applying catastrophe theory, a general safety index is derived, which indicates the relative safety level of a road section. Finally, all road sections can be ranked based on the general safety index. A case study shows encouraging results where (1) the safety index is highly correlated with real mortality rates and (2) the safety index successfully identifies most dangerous road sections. The proposed method can be considered as a promising supplementary safety evaluation method that could help traffic engineers to better understand safety implications of first-class highways in China.

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