Application of a simplified method of calculating longitudinal moments to the Ontario highway bridge design code

1979 ◽  
Vol 6 (1) ◽  
pp. 36-50 ◽  
Author(s):  
Baidar Bakht ◽  
M. S. Cheung ◽  
T. S. Aziz
Keyword(s):  
Orthotropic Plate ◽  
Concrete Beams ◽  
Plate Theory ◽  
Highway Bridge ◽  
Live Load ◽  
Design Code ◽  
Worked Example ◽  
Development Methodology ◽  
Simplified Method ◽  
Torsionally Stiff

A manual method for calculating the design live load longitudinal moments in superstructures of most right bridges is presented. The bridge types that can be analysed by this method are: slab bridges, beam and slab bridges incorporating both steel and concrete beams, bridges incorporating wooden beams, and slabs on hollow trapezoidal or other such torsionally stiff beams.The proposed method was developed by orthotropic plate theory, and was checked by the grillage analogy method. The basis of the method and details of development methodology are presented. The effect of the various parameters on the transverse distribution of longitudinal moments is discussed.The method is useful not only for the ease with which design longitudinal moments can be obtained, but also because it enables the designer to investigate the effects of making changes in the design on distribution characteristics.To demonstrate the simplicity of the solution a worked example is included.

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 Unified approach for bridge deck design

2021 ◽  
Author(s):  
Karim Meleka
Keyword(s):  
Bridge Deck ◽  
Flexural Rigidity ◽  
Single Point ◽  
Point Load ◽  
Live Load ◽  
Design Code ◽  
Design Alternatives ◽  
Wheel Loading ◽  
Torsionally Stiff ◽  
Concrete Deck

Current Canadian Highway Bridge Design Code includes design provisions to establish live load demands in (i) reinforced concrete decks over longitudinal girders, (ii) orthotropic deck over longitudinal girders, and (iii) orthotropic deck over transverse beams. However, it only provides an equation for factored applied moment on concrete deck under single point load. Similar equations for orthotropic decks are as yet unavailable. As such, parametric study was conducted to lead to new empirical expressions for moment in bridge decks subjected to truck wheel loading considering each of the three cases of orthotropy: (i) relatively torsionally stiff, flexurally soft decks; (ii) relatively uniformly thick decks; and (iii) relatively torsionally soft, flexurally stiff decks. Using the proposed formulations, bridge deck design can be treated in a unified way across different deck types, accounting for longitudinal-transverse flexural rigidity of decks. Application of these methods can significantly simplify the analysis of decks and allow bridge engineers to make comparisons across different deck design alternatives.

Some observations on BWIM data collected in Manitoba

2020 ◽  
Vol 47 (1) ◽  
pp. 88-95
Author(s):  
B. Algohi ◽  
B. Bakht ◽  
H. Khalid ◽  
A. Mufti ◽  
J. Regehr
Keyword(s):  
Highway Bridges ◽  
Highway Bridge ◽  
Live Load ◽  
Design Code ◽  
Bridge Design ◽  
Canadian Province ◽  
Load Effects ◽  
Long Term Performance ◽  
Term Performance

Three highway bridges in the Canadian province of Manitoba are being monitored continuously not only for their long-term performance but also for bridge weighing-in-motion (BWIM). Data collected for the BWIM study has led to some observations that have far-reaching consequences about the design and evaluation loads for highway bridges. This paper presents the well-known concept of equivalent base length, Bm, as a useful tool for comparing trucks with different axle weight and spacing configurations as they influence load effects in all bridges. It is discussed that the statistics of gross vehicle weights (GVWs), W, collected over a one-month period is not significantly different from that for the GVW data collected over a longer period. A rational method concludes that the value of W for the CL-W Truck, the design live load specified by the Canadian Highway Bridge Design Code, is 555 kN for Manitoba. The observed truck data in Manitoba presented on the W–Bm space is found to be similar to that collected in the Canadian province of Ontario more than four decades ago. It was also found that the multi-presence factors, accounting for the presence of side-by-side trucks in two-lane bridges, specified in North American bridge design and evaluation codes are somewhat conservative.

scholarly journals Unified approach for bridge deck design

2021 ◽  
Author(s):  
Karim Meleka
Keyword(s):  
Bridge Deck ◽  
Flexural Rigidity ◽  
Single Point ◽  
Point Load ◽  
Live Load ◽  
Design Code ◽  
Design Alternatives ◽  
Wheel Loading ◽  
Torsionally Stiff ◽  
Concrete Deck

Current Canadian Highway Bridge Design Code includes design provisions to establish live load demands in (i) reinforced concrete decks over longitudinal girders, (ii) orthotropic deck over longitudinal girders, and (iii) orthotropic deck over transverse beams. However, it only provides an equation for factored applied moment on concrete deck under single point load. Similar equations for orthotropic decks are as yet unavailable. As such, parametric study was conducted to lead to new empirical expressions for moment in bridge decks subjected to truck wheel loading considering each of the three cases of orthotropy: (i) relatively torsionally stiff, flexurally soft decks; (ii) relatively uniformly thick decks; and (iii) relatively torsionally soft, flexurally stiff decks. Using the proposed formulations, bridge deck design can be treated in a unified way across different deck types, accounting for longitudinal-transverse flexural rigidity of decks. Application of these methods can significantly simplify the analysis of decks and allow bridge engineers to make comparisons across different deck design alternatives.

Bridge evaluation by mean load method per the Canadian Highway Bridge Design Code

2005 ◽  
Vol 32 (4) ◽  
pp. 678-686 ◽  
Author(s):  
Alexander Au ◽  
Clifford Lam ◽  
Akhilesh C Agarwal ◽  
Bala Tharmabala
Keyword(s):  
Traffic Load ◽  
Alternative Methods ◽  
Highway Bridge ◽  
Live Load ◽  
Design Code ◽  
Bridge Design ◽  
Traffic Loads ◽  
Extreme Load ◽  
Bridge Evaluation ◽  
The Mean

The Canadian Highway Bridge Design Code (CHBDC) provides two alternative methods for evaluating the strength of existing bridges. The load and resistance factor method provides a general approach and covers the most extreme load situations that can occur in a general bridge population. The mean load method considers the uncertainties of loads acting on a specific bridge, the method of analysis, and resistance of the structure involved, and thus can provide a more accurate evaluation of individual bridges. Since traffic load represents a major portion of bridge loads, a better evaluation of specific bridges is obtained by using the statistical parameters of traffic loads observed on the structure. However, the overall accuracy depends heavily on capturing the most critical loading conditions during the survey periods. The mean load method is particularly valuable where actual traffic loads are expected to be significantly lower than those used in code calibration and when the potential economic benefits arising from a more realistic evaluation outweigh the extra costs of live load data collection and analysis. This paper demonstrates that the mean load method using site-specific traffic loading information can lead to a significantly higher live load-carrying capacity of a bridge.Key words: highway bridges, bridge evaluation, reliability, mean load method, bridge testing.

Evaluation of the new Canadian highway bridge design code shear provisions for concrete beams with fiber-reinforced polymer reinforcement

2008 ◽  
Vol 35 (6) ◽  
pp. 609-623 ◽  
Author(s):  
Ahmed K. El-Sayed ◽  
Brahim Benmokrane
Keyword(s):  
Concrete Beams ◽  
Reinforced Concrete Beams ◽  
Fiber Reinforced Polymer ◽  
Highway Bridge ◽  
Test Results ◽  
Fiber Reinforced ◽  
Design Code ◽  
Bridge Design ◽  
Shear Design ◽  
Reinforced Polymer

The Canadian highway bridge design code (CHBDC) contains provisions for designing concrete members with fiber-reinforced polymer (FRP) reinforcement. In the second edition of the code, new shear design procedures for FRP-reinforced sections are provided. These procedures are consistent with those for steel-reinforced members in the code, in consideration of some modifications that account for the substantial differences between FRP and steel reinforcement. The shear approach adopted in the CHBDC follows the traditional approach of Vc + Vs for shear design. This paper presents an evaluation of this approach by comparing it with experimental shear strengths of available test data on beams longitudinally reinforced with FRP bars and with or without FRP stirrups. In addition, the CHBDC approach was compared with the FRP shear design provisions currently in effect in North America using the available test results. The comparison shows that the CHBDC method significantly underestimates the shear strength of FRP-reinforced concrete beams. A proposed modification to this method is presented and verified against available test results.

Water Entry of a Wedge by Hydroelastic Orthotropic Plate Theory

1999 ◽  
Vol 43 (03) ◽  
pp. 180-193 ◽  
Author(s):  
Odd M. Faltinsen
Keyword(s):  
Impact Velocity ◽  
Cross Sections ◽  
Orthotropic Plate ◽  
Plate Theory ◽  
Three Dimensional ◽  
Water Entry ◽  
Natural Period ◽  
Cross Sectional ◽  
Flow Effects ◽  
The Impact

Water entry of a hull with wedge-shaped cross sections is analyzed. The stiffened platings between two transverse girders on each side of the keel are separately modeled. Orthotropic plate theory is used. The effect of structural vibrations on the fluid flow is incorporated by solving the two-dimensional Laplace equation in the cross-sectional fluid domain by a generalized Wagner's theory. The coupling with the plate theory provides three-dimensional flow effects. The theory is validated by comparison with full-scale experiments and drop tests. The importance of global ship accelerations is pointed out. Hydrodynamic and structural error sources are discussed. Systematic studies on the importance of hydroelasticity as a function of deadrise angle and impact velocity are presented. This can be related to the ratio between the wetting time of the structure and the greatest wet natural period of the stiffened plating. This ratio is proportional to the deadrise angle and inversely proportional to the impact velocity. A small ratio-means that hydroelasticity is important and a large ratio means that hydroelasticity is not important.

The Experimental Analysis of the Nonlinear Effects of Live Load of E-Dong Yangtze River Highway Bridge

2014 ◽  
Vol 587-589 ◽  
pp. 1672-1679
Author(s):  
Hui Ling Chen
Keyword(s):  
Geometric Nonlinearity ◽  
Yangtze River ◽  
Nonlinear Effects ◽  
Highway Bridge ◽  
Live Load ◽  
Load Effect ◽  
Large Span ◽  
Cable Stayed Bridge ◽  
Long Span ◽  
Actual Response

E-dong Yangtze River Highway Bridge is a compound double Tower Double Suspension Cable stayed bridge with a main-span of 926m. it has very distinctive geometric nonlinearity, which features as a long span, a high Tower, a soft construction, etc. in order to analyze how the geometric nonlinearity will affect the live load effect of large-span cable stayed bridge, we adopted the experimental results of the static experiments of the E-dong bridge to do a comparative analysis, during which all the calculation was based on the limited Factor theory. And the results showed that, the nonlinear results fit much better with the actual response of large-span cable stayed bridge, while the linear results produced a big difference.

Sign in / Sign up

Export Citation Format

Share Document