Canadian highway bridge evaluation: derivation of Clause 12 of CAN/CSA-S6-88

1992 ◽  
Vol 19 (6) ◽  
pp. 1007-1016 ◽  
Author(s):  
F. Michael Bartlett ◽  
Peter G. Buckland ◽  
D. J. Laurie Kennedy
Keyword(s):  
Key Words ◽  
Highway Bridges ◽  
Highway Bridge ◽  
Dead Load ◽  
Resistance Factors ◽  
Bridge Evaluation ◽  
Load And Resistance Factors ◽  
Practical Guidelines ◽  
New Criteria

Improvements to Clause 12 of CAN/CSA Standard S6-88 "Design of highway bridges" required the transformation of basic findings into a form suitable for use by evaluators. The number of dead load categories was reduced, and the rating equation was simplified. Rating factors calculated using the new criteria were checked against past practice. Practical guidelines for material grade identification and the evaluation of deteriorated components were developed. Three examples of the application of the provisions are included. Key words: calibration, codes (standards), evaluation, highway bridges, load and resistance factors, mean load method, safety.

New Safety-Based Checking Procedure for Overloads on Highway Bridges

1996 ◽  
Vol 1541 (1) ◽  
pp. 22-28 ◽  
Author(s):  
Gongkang Fu ◽  
Osman Hag-Elsafi
Keyword(s):  
Highway Bridges ◽  
Load Rating ◽  
Truck Traffic ◽  
Resistance Factors ◽  
Evaluation Codes ◽  
Bridge Safety ◽  
Bridge Evaluation ◽  
Load And Resistance Factors ◽  
Checking Procedure

Overweight trucks exceeding legal weight limits are seen crossing highway bridges. Many states adopt the AASHTO rating concept with or without an overstress criterion to check overweight permits for bridge evaluation. However, the basis of these overstress criteria has not been well documented, and the AASHTO load-rating concept is not intended to be applicable to overweight truck traffic. The development of a new overload-permit checking procedure for bridge evaluation, in the format of load and resistance factors and based on relatively uniform bridge safety, is presented. Annual and trip overload permits for nondivisible loads are covered. This procedure may be included in bridge evaluation codes for overload checking.

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.

scholarly journals Reliability Estimation for Highway Bridges

2020 ◽  
Author(s):  
Nafiseh Kiani
Keyword(s):  
Reliability Index ◽  
Structural Reliability ◽  
Limit State ◽  
Highway Bridges ◽  
Reliability Estimation ◽  
State Function ◽  
Limit States ◽  
Resistance Factors ◽  
Load And Resistance Factors ◽  
Reliability Methods

Structural reliability analysis is necessary to predict the uncertainties which may endanger the safety of structures during their lifetime. Structural uncertainties are associated with design, construction and operation stages. In design of structures, different limit states or failure functions are suggested to be considered by design specifications. Load and resistance factors are two essential parameters which have significant impact on evaluating the uncertainties. These load and resistance factors are commonly determined using structural reliability methods. The purpose of this study is to determine the reliability index for a typical highway bridge by considering the maximum moment generated by vehicle live loads on the bridge as a random variable. The limit state function was formulated and reliability index was determined using the First Order Reliability Methods (FORM) method.

scholarly journals Analisis Perhitungan Jembatan Gelagar I pada Jembatan Jalan Raya dan Jembatan Kereta Api

2013 ◽  
Vol 4 (1) ◽  
pp. 517
Author(s):  
Irpan Hidayat
Keyword(s):  
Highway Bridges ◽  
Highway Bridge ◽  
Live Load ◽  
Railway Bridge ◽  
Dead Load ◽  
Railway Bridges ◽  
Railroad Bridge ◽  
Limit Stress ◽  
Girder Bridge ◽  
Bridge Spans

The bridge is a means of connecting roads which is disconnected by barriers of the river, valley, sea, road or railway. Classified by functionality, bridges can be divided into highway bridge and railroad bridge. This study discusses whether the use of I-girder with 210 m height can be used on highway bridges and railway bridges. A comparison is done on the analysis of bridge structure calculation of 50 m spans and loads used in both the function of the bridge. For highway bridge, loads are grouped into three, which are self weight girder, additional dead load and live load. The additional dead loads for highway bridge are plate, deck slab, asphalt, and the diaphragm, while for the live load is load D which consists of a Uniform Distributed Load (UDL) and Knife Edge Load (KEL) based on "Pembebanan Untuk Jembatan RSNI T-02-2005". The load grouping for railway bridge equals to highway bridge. The analysis on the railway bridges does not use asphalt, and is replaced with a load of ballast on the track and the additional dead load. Live load on the structure of the railway bridge is the load based on Rencana Muatan 1921 (RM.1921). From the calculation of the I-girder bridge spans 50 m and girder height 210 cm for railway bridge, the stress on the lower beam is over the limit stress allowed. These results identified that the I-girder height 210 cm at the railway bridge has not been able to resist the loads on the railway bridge.

scholarly journals Canadian highway bridge evaluation: load and resistance factors

1992 ◽  
Vol 19 (6) ◽  
pp. 992-1006 ◽  
Author(s):  
D. J. Laurie Kennedy ◽  
Darrel P. Gagnon ◽  
David E. Allen ◽  
James G. MacGregor
Keyword(s):  
Field Measurements ◽  
Highway Bridges ◽  
Live Load ◽  
Safety Criterion ◽  
Transverse Distribution ◽  
Resistance Factors ◽  
Load Factors ◽  
Target Values ◽  
Load And Resistance Factors ◽  
Live Loads

Consistent load and resistance factors are developed for a range of target values of the reliability index, β, following first-order second-moment analysis techniques for use in the evaluation of highway bridges. Dead load factors are established for steel girders, concrete girders, concrete bridge decks, and wearing surfaces, taking into account the statistical variations of weights and the range of load fractions as determined from field measurements. Live load factors are established for four categories of live loads: NP — non-permit traffic that are permitted by legislation; PM — permit, multiple trip, bulk haul, divisible loads; PS — permit, single trip, unsupervised, mixed with non-permit traffic; and PC — permit, controlled, supervised extremely heavy loads with escort. These live load factors are based on field surveys of truck weights, in Alberta and elsewhere. The event curves for NP, PS, and PM traffic have been used to determine the maximum annual truck, as the period of evaluation was chosen as 1 year based on a life-safety criterion-related to the consequences of failure. Because PC traffic is so rare, it was dealt with on an event basis. Impact data of others were analyzed to determine the appropriate bias coefficients and coefficients of variation. Uncertainties in the transverse distribution of both dead and live loads were also considered.Resistance factors are based on statistical data reported in the literature and take into account the variation in material properties, member size, and the resistance formulations. Key words: dead and live load factors, resistance factors, impact, maximum annual, traffic categories, transverse distribution, weight fractions.

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.

Soil–steel structure design by the third edition of OHBDC

1992 ◽  
Vol 19 (4) ◽  
pp. 545-550 ◽  
Author(s):  
George Abdel-Sayed ◽  
Baidar Bakht ◽  
Ernest T. Selig
Keyword(s):  
Key Words ◽  
Steel Structure ◽  
Structure Design ◽  
Buckling Analysis ◽  
New Method ◽  
Highway Bridge ◽  
Dead Load ◽  
Design Code ◽  
The Third ◽  
Conduit Wall

The Ontario Highway Bridge Design Code (OHBDC) introduced in 1979 a new set of provisions for the design of soil–steel bridges. Some of these provisions have been revised in the third edition of OHBDC (1991) to reflect the outcome of research that has been conducted since. This paper presents details of these revisions and provides the reasons for their inclusion. In particular, a new method of calculating dead load thrust and improvement to the buckling analysis of the conduit wall are discussed. Key words: buckling, pipe-arch, soil–steel structure, thrust.

Canadian highway bridge evaluation: a general overview of Clause 12 of CSA Standard CAN/CSA-S6-88

1992 ◽  
Vol 19 (6) ◽  
pp. 981-986 ◽  
Author(s):  
Peter G. Buckland ◽  
F. Michael Bartlett
Keyword(s):  
Key Words ◽  
Design Stage ◽  
Highway Bridge ◽  
General Overview ◽  
Load Factors ◽  
Bridge Evaluation

Because upgrading a bridge is usually far more costly than incorporating extra capacity at the design stage, a different approach is appropriate. Clause 12 of CAN/CSA-S6-88, published in 1990, was developed specifically for evaluation. The development of Clause 12 is reviewed, as is the philosophy of varying the load factors based on how well the loads are known, the consequences of failure, and other variables. An overview of Clause 12 is presented and reference is given to three companion papers describing the derivation of numerical values used in Clause 12 and their adaptation for the Standard. Key words: bridges, evaluation, assessment.

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