COMPARATIVE ANALYSIS OF HORIZONTALLY SKEWED COMPOSITE I-GIRDER BRIDGES (original) (raw)
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IJERT-Stress Assessment of Skew Composite Steel I-Girder Bridge
International Journal of Engineering Research and Technology (IJERT), 2021
https://www.ijert.org/stress-assessment-of-skew-composite-steel-i-girder-bridge https://www.ijert.org/research/stress-assessment-of-skew-composite-steel-i-girder-bridge-IJERTV10IS050288.pdf Due to the lack of space required for more traditional right bridges, skewed geometries in urban areas are more efficient to design bridges. Shifting of load from concrete slab to steel girder in a skew steel concrete composite bridge is a multifaceted three dimensional phenomenon. Grillage analysis, finite element analysis method & load distribution method are the popular method of analysis for this type of bridge. Still Finite element analysis is considered to be a precise method, it takes high effort in data preparation, modeling and analysis of structure, and interpretation of results. For skew bridges, AASHTO given a method which too traditional, as it does not consider the fall in girder moments due to skew bridge. On the contrary, AASHTO LRFD equation gives precise results, but it is considered to be bulky in practice. Using different method of analysis, several researchers have investigated the load distribution in skew bridges and presented empirical formulae for moment distribution factors for bridges subjected to AASHTO truck loading. But only a small number of studies have been done on skew composite bridges subjected to IRC load and dead load. Several points in the girder are checked to assure the girder is not over-stressed at any point. The main aim of this work is to conduct a parametric study to study the key parameters that may control the load stress characteristics of a skew steel-concrete composite bridge. Grillage Analogy based on stiffness matrix approach using "STAAD Pro" has been used for these stress analysis. A wide parametric study is done, in which various skew steel-concrete composite bridge models are analyzed to evaluate their load stress for Bending moment and shear under dead load and IRC live load conditions. The key parameters considered in the study are the span length (20m, 25m, 30m and 35m), skew angle (0-50 deg) taken at the interval of 10degree and number of main girders (4 and 5). Bridges with skew angle greater than 450 are rare. Based on the parametric study, bending stresses & shear stresses are determined for skew composite bridges subjected to IRC loading as well as dead load.
Modelling and Analysis of I-Girder Bridge Deck Using Grillage Analogy
International Journal for Research in Applied Science and Engineering Technology IJRASET, 2020
The majority of highway bridges are girder type structures, either single spans or continuous spans. Determining the principal effects of the various loading combinations can often be achieved with a 2-dimensional analytical model but for overall absolute analysis which is actually more complicated a 3-dimensional model is needed. This paper elaborates the correct analysis and modelling techniques for typical prestressed concrete bridge deck girder by using grillage analysis. The structural model is developed as per FE discretization in Staad Pro software. For the purpose of analysis, dead load (self-weight, wearing coat, super imposed dead load, footpath live load) and vehicular live loads are considered as per IRC: 6-2016. A series of applications are executed in order to verify the efficiency and the accuracy. Linear static analysis is carried and the design values of bending moment and shear force for the class A 70 R tracked vehicle are computed.
IJERT-A Comparative Study on T Girder Bridge Deck using Grillage Analogy and Finite Element Method
International Journal of Engineering Research and Technology (IJERT), 2021
https://www.ijert.org/a-comparative-study-on-t-girder-bridge-deck-using-grillage-analogy-and-finite-element-method https://www.ijert.org/research/a-comparative-study-on-t-girder-bridge-deck-using-grillage-analogy-and-finite-element-method-IJERTV10IS060034.pdf Concrete slabs and t-girder bridges have been the dominant bridges in India. Especially in recent years, many road constructions are underway, some are under construction, and some road projects are planned to be carried out in the future. As the project becomes larger, it is necessary to improve the design method and make it more effective every day. It summarizes the requirements of the new bridge and the important features of the planned site and makes it the basis for each design. Initially, the dimensions of the structural members were chosen according to the designer's experience, and at a later stage, the engineering software was used to compare the alternative software and optimize the part size. Finally, a complete analysis and analysis of all important construction phases and detailed shop drawings will be carried out.
PARAMETRIC STUDY OF SKEW ANGLE ON BOX GIRDER BRIDGE DECK
Box girder bridge deck, is the most common type of bridges in world and India, it consists of several Slab or girders. The span in the direction of the roadway and connected across their tops and bottoms by a thin continuous structural stab, the longitudinal box girders can be made of steel or concrete. The Simple supported single span concrete bridge deck is presented in present study. Skewed bridges are suitable in highway design when the geometry of straight bridges is not possible. The skew angle can be defined as the angle between the normal to the centerline of the bridge and the centerline of the abutment or pier cap. Due to high traffic road can hardly modified in order to eliminate the skew. Therefore, considerable numbers of skew bridge decks are constructed. The skew angle effects on the behaviour of the bridge. Therefore, there is need for more research to study the effect of skew angle on performance of bridges. In the present study, the effect of change in skew angles with normal bridge is studied. Longitudinal moment, shear force, deflection and transverse moment are computed by modeling using STAAD-PRO with IRC loadings and results are compared.
Grillage Modeling Approach Applied to Simple-span Slab-girder Skewed Bridges for Dynamic Analysis
U.Porto Journal of Engineering
This study involves the applicability of a simplified modeling technique to simple-span slab-girder skewed bridges for dynamic analysis, based on grillage modeling strategies. To evaluate the applicability of this technique, skew angles ranging from 0° to 60° are studied. The ability to capture vibration modes of grillage models is compared with three-dimensional (3-D) finite element (FE) models, using shell and frame elements. The effect of the skew angle in the grillage modeling technique of the bridge's deck and the grillage model accuracy associated with the orientation of the transverse grillage members (TGMs) are studied. The grillage modeling technique eliminates shell elements to model the slab, reducing the number of degrees of freedom and the computational time in the bridge model, but, although its simplicity, demonstrates good ability to capture the vibration modes.
IJRASET, 2021
The present paper shows the effects of varying skew angles on pre-stressed concrete (PSC) bridges using finite elemental method. Studies are carried out on PSC bridge decks to understand the influence of skew angle and loading on behaviour of bridges. The results of skewed bridges are compared with straight bridges for IRC Class AA Tracked loading. Also, a comparative analysis of the response of skewed PSC Slab Bridge decks with that of equivalent straight bridge decks is made. The variation of maximum longitudinal bending moment (BM), maximum transverse moment, maximum torsional moment, and maximum longitudinal stresses deflection at obtuse corner, acute corner with skew angles are studied for bridge deck. It is found that Live load longitudinal bending moments decreases with an increase in skew angle, whereas a maximum transverse moment and maximum torsional moment increases with an increase in skew angle. The benefit of pre-stressing is reflected in considerable decrease in the longitudinal bending moment, transverse moment and longitudinal stresses. The models are analysed with the help of software CSI-Bridge V 20 Version.
IJERT-Performance Based Analysis of Bridge Deck For Distinctive Girder Types
International Journal of Engineering Research and Technology (IJERT), 2014
https://www.ijert.org/performance-based-analysis-of-bridge-deck-for-distinctive-girder-types https://www.ijert.org/research/performance-based-analysis-of-bridge-deck-for-distinctive-girder-types-IJERTV3IS080712.pdf Bridge decks must withstand one of the most damaging types of live load forces i.e. vehicle loads. In this research work, the bridge deck is modeled as a simply supported beam with the bridge deck slab spanning in one direction. Analysis for discrete model is done using the finite element method. This Thesis presents the results related to finite element analysis (FEA) of simply supported reinforced concrete bridge deck of different deck thicknesses (375mm to 825mm) and constant width of 12 m, without footpath under Indian Road Congress (IRC) vehicle load classes. Hence, a total of 128 numbers of cases were analyzed. The Dimension of deck slabs are taken from standard drawings of the Ministry of Road Transport & Highways-1991. And the deck was supported by four distinct types of girders for IRC Class 70R and IRC Class AA loading. The study indicates that the thickness of deck slab contributes a major role in carrying the vehicle loads. The increase in thickness reduces the loss in ultimate Moment carrying capacity; decrease the maximum deck stress and live load deflection; helps distribute deck live loads more evenly to the girders and increases the deck service life.
Analysis and Behaviour of Skewed Box Girder Bridge
2021
Box girder bridge is different from bridges which differ in reliability, economy and aesthetic appearance. Box Girder Bridge has excellent strength and torsional rigidity. Box girders are used for most long spans. This study shows the forces and moments of other results from 0 to 60-degree skew angles. The effect of the same span with a skew angle of 0 to 60 degrees is different. In this study the span is 31 m long and the effective span 30 m. A 2-cell box girder with a width of 9.5 m and a depth of 2.5 m. In this study, different IRC codes are used for the load. The STAAD PRO V8i software are used for the analysis of grillage models. Models are simply supported. Interestingly, the torsion was more exaggerated than the bending moment and deflection. The effects of reaction and torsion angle are mainly observed at obtuse corner rather than acute corner. The shear forces for the permanent load of each support are different and gradually increase and decrease from the LHS side to the R...