scholarly journals Curved Concrete Slab-On-Steel I-Girder Bridges

Author(s):  
Joseph Wassef

A parametric study was conducted, using the finite-element method, to study the load distribution characteristics of curved composite I-girder bridges under truck loading. The influence of several geometric parameters on the moment, and deflection distribution factors, as well as warping stresses in straight and curved composite I-girder bridges was examined. For straight bridges, the moment distribution factors were correlated with those specified in the Canadian Highway Bridge Design Code of 2000, CHBDC. Also the magnitudes of warping stresses in the steel bottom flanges were correlated with the specified limits in bridge codes. The results showed that the CHBDC moment distribution factors significantly overestimate the structural response of straight bridges considered in this study. It was also observed that the curvature limitation specified in the CHBDC to treat a curved bridge of low curvature as a straight one underestimate the structural response.

2021 ◽  
Author(s):  
Joseph Wassef

A parametric study was conducted, using the finite-element method, to study the load distribution characteristics of curved composite I-girder bridges under truck loading. The influence of several geometric parameters on the moment, and deflection distribution factors, as well as warping stresses in straight and curved composite I-girder bridges was examined. For straight bridges, the moment distribution factors were correlated with those specified in the Canadian Highway Bridge Design Code of 2000, CHBDC. Also the magnitudes of warping stresses in the steel bottom flanges were correlated with the specified limits in bridge codes. The results showed that the CHBDC moment distribution factors significantly overestimate the structural response of straight bridges considered in this study. It was also observed that the curvature limitation specified in the CHBDC to treat a curved bridge of low curvature as a straight one underestimate the structural response.


2021 ◽  
Author(s):  
Ahmed Diab ◽  
Khaled Sennah

In bridge analysis, designers calculate maximum bending moment, MT, and shear force, VT, of a bridge girder under truck loading, then use available truck fraction, FT to generate the longitudinal live load effects. This Thesis presents structural analysis of different girder configurations subjected to CL-W truck loading. Girder geometries include single-, two-, three- and four-span girders. The maximum shear, deflection and moments were plotted and then used to develop equations to represent their values. Furthermore, a software was developed to perform composite steel I-girder design. The software optimizes the I-girder size based on CHBDC design procedure. Using the developed software, a parametric study was conducted to determine the required composite moment of inertia, moment of inertia of the bare steel section and steel web area to satisfy all design requirements. Empirical equations for these three properties were developed to assist bridge designers in estimating steel I-section sizes for contract bidding.


1988 ◽  
Vol 15 (2) ◽  
pp. 232-239 ◽  
Author(s):  
Baidar Bakht ◽  
Leslie G. Jaeger

In many slab-on-girder bridges, especially those that are continuous over two or more spans, the moment of inertia of a girder varies significantly along the length of the bridge. This paper critically examines the practice of analyzing such bridges for load distribution by methods that make the assumption of constant longitudinal torsional and flexural rigidities. It is found that this practice may not be valid for those slab-on-girder bridges in which variations of the girder moments of inertia are very large.A recommended procedure is given for cases in which the variation in moment of inertia is not too severe. The procedure involves (a) the determination of total bending moments, treating the bridge as a beam of variable moment of inertia, and (b) the determination of an equivalent constant moment of inertia for beams of varying moment of inertia. Using this procedure the load distribution properties of the bridge can be realistically analyzed by those computer-based methods (e.g., orthotropic plate, finite strip, and semicontinuum methods) or manual methods (e.g., AASHTO and Ontario methods) that cannot directly take account of the variation of longitudinal flexural rigidity.The validity of the recommended procedure is established by comparing its results with those of the grillage analysis method that does take account of the variation of the girder moment of inertia. Key words: bridge analysis, girders, load distribution, slab-on-girder bridges.


2021 ◽  
Author(s):  
Mohammed A. Al-Hashimy

The use of complex interchanges in modern highway urban systems have increased recently in addition to the desire to conform to existing terrain; both have led to increase the demand for horizontally curved bridges. One type of curved bridges consists of composite concrete deck over steel I-girders which has been the preferred choice due to its simplicity in fabrication, transportation and erection. Although horizontally curved steel bridges constitute roughly one-third of all steel bridges being erected today, their structural behavior still not well understood. Due to its geometry, simple presence of curvature in curved bridges produces non uniform torsion and consequently, lateral bending moment (warping or bi-moment) in the girder flanges. The presence of the lateral bending moments would significantly complicate the analysis and the design of the structure. Hence, a parametric study is required to scrutinize a simplified method in designing horizontally curved steel I-girder bridges. A parametric study is conducted, using the finite-element analysis software "SAP2000", to examine the key parameters that may influence the load distribution on the curved composite steel girders. Based on the data generated from the parametric study, sets of empirical equations are developed for the moment and shear distribution factors for straight and curved steel I-girder bridges when subjected to the Canadian Highway Bridge Design Code (HCHBDC) truck loading.


2021 ◽  
Author(s):  
Ahmed Diab ◽  
Khaled Sennah

In bridge analysis, designers calculate maximum bending moment, MT, and shear force, VT, of a bridge girder under truck loading, then use available truck fraction, FT to generate the longitudinal live load effects. This Thesis presents structural analysis of different girder configurations subjected to CL-W truck loading. Girder geometries include single-, two-, three- and four-span girders. The maximum shear, deflection and moments were plotted and then used to develop equations to represent their values. Furthermore, a software was developed to perform composite steel I-girder design. The software optimizes the I-girder size based on CHBDC design procedure. Using the developed software, a parametric study was conducted to determine the required composite moment of inertia, moment of inertia of the bare steel section and steel web area to satisfy all design requirements. Empirical equations for these three properties were developed to assist bridge designers in estimating steel I-section sizes for contract bidding.


2002 ◽  
Vol 29 (1) ◽  
pp. 119-124
Author(s):  
Patrick Paultre ◽  
Caroline Moisan

Slabs with continuous drop panels between column lines facilitate formwork, make long spans possible in addition to increase punching shear resistance around supports and provide unobstructed spans with minimum structural floor depth resulting in lower floor-to-floor heights. The moment distribution in such slabs is different from that in conventional flat plates or slabs with drop panels systems. Dimensioning according to the current provisions in CSA A23.3-94 is problematic because the continuous drop panels are subject to moments exceeding the minimum values allowed by the Code for conventional slab systems. This analytical study presents the moment distribution in slabs with continuous drop panels in an attempt to provide more realistic transverse moment distribution factors.Key words: reinforced concrete, slab systems, slab design, drop panel, moment distribution.


2021 ◽  
Author(s):  
Mohammed A. Al-Hashimy

The use of complex interchanges in modern highway urban systems have increased recently in addition to the desire to conform to existing terrain; both have led to increase the demand for horizontally curved bridges. One type of curved bridges consists of composite concrete deck over steel I-girders which has been the preferred choice due to its simplicity in fabrication, transportation and erection. Although horizontally curved steel bridges constitute roughly one-third of all steel bridges being erected today, their structural behavior still not well understood. Due to its geometry, simple presence of curvature in curved bridges produces non uniform torsion and consequently, lateral bending moment (warping or bi-moment) in the girder flanges. The presence of the lateral bending moments would significantly complicate the analysis and the design of the structure. Hence, a parametric study is required to scrutinize a simplified method in designing horizontally curved steel I-girder bridges. A parametric study is conducted, using the finite-element analysis software "SAP2000", to examine the key parameters that may influence the load distribution on the curved composite steel girders. Based on the data generated from the parametric study, sets of empirical equations are developed for the moment and shear distribution factors for straight and curved steel I-girder bridges when subjected to the Canadian Highway Bridge Design Code (HCHBDC) truck loading.


2021 ◽  
Author(s):  
Magued W. Ibrahim

As Ontario bridge infrastructure enters the era of maintenance, rehabilitation and replacement, prefabricated bridge systems will certainly have many advantages as compared to the conventional systems. Prefabricated systems can be quickly assembled and the traffic can be opened in a very short period of time, minimizing the lane closure time, reducing the cost and design time, and minimizing forming and labour work. The Canadian Highway Bridge Design Code specifies simplified design method for slab-on-girder bridges in the form of moment and shear distribution factors. This thesis presents a parametric study, using the finite-element method, on a series of precast Wide-Flange CPCI girder bridges to examine the applicability of the CHBDC load distribution factors to this prefabricated bridge system. The parameters considered in this study include span length, number of lanes, number of girders, live load conditions, presence of intermediate diaphragms, and type of connections between individual girders. This study revealed that CHBDC load distribution factors generally overestimate the structural response of such bridges. As a result, a refined set of load distribution factor equations were developed.


2021 ◽  
Author(s):  
Manal Ibrahim

Bridges formed of concrete deck slab over built-up steel-box girders are frequently used in bridge construction for their economic and structural advantages. Box girder bridges impose structural challenges to get the straining actions for the design of girders. The objective of this study is to determine the load distribution characteristics for continuous composite multiple–box girder bridges under CHBDC truck loading. An extensive parametric study was conducted using the three-dimensional finite element to evaluate the moment and shear distribution factors when bridges subjected to CHBDC truck loading. The parameters considered in this study are the span length, number of lanes and number of boxes. Then, simple empirical formula for the bending moment and shear force were developed for the structural design. Correlation of the developed expressions based on FEA results with available CHBDC and AASHTO-LRFD formula showed that the former allow engineers to design such bridges more economically and reliably.


2021 ◽  
Author(s):  
Magued W. Ibrahim

As Ontario bridge infrastructure enters the era of maintenance, rehabilitation and replacement, prefabricated bridge systems will certainly have many advantages as compared to the conventional systems. Prefabricated systems can be quickly assembled and the traffic can be opened in a very short period of time, minimizing the lane closure time, reducing the cost and design time, and minimizing forming and labour work. The Canadian Highway Bridge Design Code specifies simplified design method for slab-on-girder bridges in the form of moment and shear distribution factors. This thesis presents a parametric study, using the finite-element method, on a series of precast Wide-Flange CPCI girder bridges to examine the applicability of the CHBDC load distribution factors to this prefabricated bridge system. The parameters considered in this study include span length, number of lanes, number of girders, live load conditions, presence of intermediate diaphragms, and type of connections between individual girders. This study revealed that CHBDC load distribution factors generally overestimate the structural response of such bridges. As a result, a refined set of load distribution factor equations were developed.


Sign in / Sign up

Export Citation Format

Share Document