scholarly journals Effect of Skew Angles on Longitudinal Girder and Deck Slab of Prestressed Concrete T Beam Girder Bridges

2021 ◽  
Vol 9 (10) ◽  
pp. 414-420
Author(s):  
Ms. Ashwini Hanchate
Keyword(s):  
Prestressed Concrete ◽  
Bridge Decks ◽  
Bending Moment ◽  
Torsional Moment ◽  
Skew Angle ◽  
Skewed Bridges ◽  
Girder Bridges ◽  
Longitudinal Bending ◽  
Skew Angles ◽  
Deck Slab

Abstract: 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. Keywords: Skew angle effect, Longitudinal moment, Transverse moment, CSI- Bridge software, Deck slab, Finite element method.

scholarly journals Effect of Skew Angle on Bridge Superstructures

2021 ◽  
Vol 9 (1) ◽  
pp. 43-48
Author(s):  
Abdelhameed H. M. Ali ◽  
Anwar Adam Ahmed
Keyword(s):  
Bridge Deck ◽  
Bending Moment ◽  
Skew Angle ◽  
Shear Forces ◽  
Bridge Superstructures ◽  
Skew Bridge ◽  
The One ◽  
The Right ◽  
Skew Angles ◽  
Zero Skew

In this paper, the effect of skew angle on reinforced concrete skew bridge decks is presented by using the grillage analogy. The actual deck system of the bridge is represented by an equivalent grillage of longitudinal and transverse beams. A span 26m of simply supported bridge deck is taken as the case study to obtain the values of the bending moment' s distribution versus span length for the one type of skewness and the results are compared against the moments of the right deck span of the bridge. The analysis results were based (BS5400) dead and live loads using Structural Analysis program (SAP2000). The analysis provided useful information about the variation of moments and shear forces with respect to change in skewness. It is concluded that in skew bridge deck, the bending moment is decreased, but torsional moments and shear forces are increased by increasing the skew angle. It is noticed that the maximum bending moment at skew angle 55o, by 76% in comparison with zero skew angle. On the other hand the maximum torsional moment increases for the same skew angle (55o) more than five times than with zero skew angles.  

Influence of Transient and Partial Footing Separation on the Seismic Response of Skewed Bridges with Soil Support

2021 ◽  
pp. 2150132
Author(s):  
Ziqi Yang ◽  
Chern Kun ◽  
Dongliang Meng ◽  
Nawawi Chouw
Keyword(s):  
Seismic Response ◽  
Large Scale ◽  
Bending Moment ◽  
Bridge Piers ◽  
Seismic Load ◽  
Skew Angle ◽  
Skewed Bridges ◽  
Design Spectrum ◽  
Bridge Structures ◽  
The Impact

Previous research has shown that the transient and partial footing separation is one of the effective methods to reduce the impact of earthquakes on bridge structures. The separation will not only temporarily stop the transfer of seismic load to structures, but also activate rigid-like body motions of the bridge piers. Most of current investigations involving footing uplift only focused on straight bridges. The influence of skew angle is rarely considered. Even though skewed bridges are common and more vulnerable to seismic load. This work reveals the simultaneous influence of skew angle and footing uplift on soil on seismic response of bridges. A bridge with a 30∘ or 45∘ skew angle, in addition to a straight bridge, was excited using a large-scale shake table. The ground excitations were stochastically simulated based on design spectrum of New Zealand standard. The result revealed that with increasing skew angle bridges will have frequent footing uplifts. In the case of a straight bridge, although allowing footing uplift is beneficial in reducing the bending moment at the pier support, it increases the longitudinal girder displacement. In contrast, in the case of 30∘ and 45∘ skewed bridges, uplifts increase the bending moments of piers and the displacements of the girder, especially in the transverse direction.

scholarly journals Experimental Evaluation of the Seismic Response of Skewed Bridges with Emphasis on Poundings between Girder and Abutments

2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Ziqi Yang ◽  
Chern Kun ◽  
Nawawi Chouw
Keyword(s):  
Seismic Response ◽  
Experimental Research ◽  
Experimental Evaluation ◽  
Shake Table ◽  
Skew Angle ◽  
Shake Table Tests ◽  
Skewed Bridges ◽  
Single Frame ◽  
Bridge Model ◽  
Skew Angles

Observations from past earthquake events indicate that skewed bridges are seismically vulnerable due to induced horizontal in-plane rotations of the girder. To date, however, very limited experimental research has been done on the pounding behaviour of skewed bridges. In this study, shake table tests were performed on a single-frame bridge model with adjacent abutments subjected to uniform ground excitations. Bridges with different skew angles, i.e., 0°, 30°, and 45°, were considered. The pounding behaviour was observed using a pair of pounding and measuring heads. The results reveal that poundings could indeed influence the responses of skewed bridges in the longitudinal and transverse directions differently and thus affect the development of the girder rotations. Ignoring pounding effects, the 30° skewed bridges could experience more girder rotations than the 45° skewed bridges. With pounding, the bridges with a large skew angle could suffer more opening girder displacements than straight bridges.

EFFECT OF SKEW ANGLE ON SEISMIC VULNERABILITY OF RC BOX-GIRDER HIGHWAY BRIDGES

2013 ◽  
Vol 13 (06) ◽  
pp. 1350013 ◽  
Author(s):  
AHMED ABDEL-MOHTI ◽  
GOKHAN PEKCAN
Keyword(s):  
Ground Motion ◽  
Seismic Vulnerability ◽  
Fragility Curves ◽  
Nonlinear Dynamic Analysis ◽  
Highway Bridges ◽  
Skew Angle ◽  
Box Girder ◽  
Skewed Bridges ◽  
Damage States ◽  
Skew Angles

In this study, the seismic vulnerability of post-tensioned reinforced concrete box-girder highway bridges with moderate-to-large skew angles to various levels of ground motion intensity is investigated. The fragility curves are generated by performing incremental nonlinear dynamic analysis (IDA) on the bridges of skew angles of 0, 30, and 60°s. A total of 45 ground motion pairs are considered to develop the fragility curves. The damage states are presented and quantified based on the column rotational ductility and superstructure displacements at the abutments. Furthermore, the fragility curves constructed are compared against those recommended by HAZUS. It is demonstrated that as the skew angle increases, skew bridges become more vulnerable to seismically induced damages. It is also shown that the HAZUS fragility curves may not lead to a consistent prediction of the vulnerability of skewed bridges.

scholarly journals Analysis of Deck Slab of Reinforced Concrete Gerber-Girder Bridge Widened by Addition of Continuous Steel-Concrete Composite Girders

2019 ◽  
Vol 14 (2) ◽  
pp. 271-284
Author(s):  
Wojciech Siekierski
Keyword(s):  
Finite Element ◽  
Reinforced Concrete ◽  
Bending Moment ◽  
Continuous Steel ◽  
Bending Moments ◽  
Girder Bridges ◽  
Concrete Girders ◽  
Moment Distribution ◽  
Girder Bridge ◽  
Deck Slab

Many Gerber-girder bridges have become obsolete in terms of deck width and load carrying capacity. If bridge replacement is not necessary, additional girders are installed. Sometimes, due to erection convenience, the added girders do not replicate the static scheme of the refurbished structure. Such an arrangement requires special attention to preserve structural durability. An example of the inappropriate arrangement of the widening of a Reinforced Concrete Gerber-girder road bridge is presented together with an alternative concept of refurbishment based on the addition of the continuous steel-concrete girders as the outermost ones. The added deck slab connects the added and the existing parts of the structure. Attention is drawn the static analysis of the added deck slab and the influence of the added outermost girders that do not replicate the static scheme of the existing ones. Due to different static schemes of the existing and the added girders, the traditional method of the deck slab analysis is inappropriate. The Finite Element 3D model is to be applied to access bending moments in the deck slab spans correctly. It is shown that: a) the analysis of the distribution of the bending moments in the existing and the added slab spans, especially near Gerber-hinges, should be based on the Finite Element 3D modelling; b) the analysis should consider live loads acting on the whole width of the Gerber-hinge span; c) the bending moment distribution in the widened deck slab is sensitive to the distance to the Gerber hinge.

FINITE ELEMENT ANALYSIS OF PRESTRESSED CONCRETE VOIDED BRIDGE DECKS

PCI Journal ◽  
1973 ◽  
Vol 18 (3) ◽  
pp. 51-66 ◽  
Author(s):  
J. C. Jofriet ◽  
G. M. McNeice ◽  
P. Csagoly
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Prestressed Concrete ◽  
Bridge Decks ◽  
Element Analysis
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