scholarly journals Curved bridges live load bending moment distribution using straight and curved girders

2022 ◽  
Vol 15 (2) ◽  
Author(s):  
Arthur da Silva Rebouças ◽  
José Neres da Silva Filho ◽  
Rodrigo Barros ◽  
Yngrid Rayane Freitas Nascimento ◽  
Pedro Mitzcun Coutinho
Keyword(s):  
Parametric Analysis ◽  
Precast Concrete ◽  
Bending Moment ◽  
3D Models ◽  
Concrete Bridges ◽  
Live Load ◽  
Distribution Factor ◽  
Moment Distribution ◽  
Curved Girders ◽  
Bridge Models

abstract: The present study focuses on comparative parametric analysis of curved precast concrete bridges using straight and curved I-girders. The live load bending moment distribution for girders was studied using the bridge curvature and its relationship with the results obtained for a straight bridge. FEM 3D models were developed with restrictions on the transverse live load positions and with two different load models types: HL-93 (AASHTO) and TB-450 (NBR 7188, 2013). The parametric analysis results were calculated using the Modification Factor (MF) and the Bending Moment Distribution Factor (BMDF), calculated from the structural analysis of each model at the midspan. Globally, an increase was found in the total bending moment for the curved bridge models in relation to the straight bridge. In the examples herein studied, the larger the bending radius, the larger the maximal bending moment in the bridge center. For the external girders, the MF increases with the increase of the L/R. For the internal ones, the MF decreases with the increase of the L/R. In addition, the occurrence of “Load Shift” was different from the rigid body behavior, for there was demonstrated a different bending moment variation between external girder (G1) in relation to its adjacent (G2). Therefore, the structural behavior of straight (SG) and curved girders (CG) was analyzed, revealing that, in the SG, a significant gap occurred in the BMDF between G1 and G2 girders for all curvatures. For L/R = 0.6, it caused a difference of 17.8% in the BMDF between the G1 and G2 girders, while on the curved girders, a difference of only 6.6% was found.

Load Distribution for Moment and Shear on Skewed Bridge Structures

2011 ◽  
Vol 255-260 ◽  
pp. 1244-1247
Author(s):  
Yi Zhou Zhuang ◽  
Tao Ji ◽  
Bao Chun Chen
Keyword(s):  
Load Distribution ◽  
Distribution Factor ◽  
Skew Angle ◽  
Shear Distribution ◽  
Moment Distribution ◽  
Bridge Structures ◽  
Skewed Bridge ◽  
Aashto Lrfd ◽  
Skew Angles ◽  
Bridge Models

Based on FEA for three bridge models with varying skew angles, the effect of skew angle on the design moment and shear of skewed bridge structures was studied and also compared to AASHTO specifications. The results show that, generally, ASSHTO-LFD covers FEM in moment distribution factor, but a little less in shear distribution factor, and that, however, AASHTO-LRFD reduces moment distribution factor below AASHTO-LFD and near to FEM, but increases shear distribution factor a lot beyond AASHTO-LFD and FEM.

Shear live load analysis of NEXT beam bridges for accelerated bridge construction

2021 ◽  
Vol 17 (3-4) ◽  
pp. 111-119
Author(s):  
Jianwei Huang
Keyword(s):  
Prestressed Concrete ◽  
Precast Concrete ◽  
Structural Safety ◽  
Accelerated Bridge Construction ◽  
Live Load ◽  
Distribution Factor ◽  
Bridge Construction ◽  
Shear Design ◽  
Bridge Structures ◽  
Live Load Distribution

Using precast concrete elements in bridge structures has emerged as an economic and durable solution to enhance the sustainability of bridges. The northeast extreme tee (NEXT) beams were recently developed for accelerated bridge construction by the Precast/Prestressed Concrete Institute (PCI). To date, several studies on the live load distribution factor (LLDF) for moment in NEXT F beam bridges have been reported. However, the LLDFs for shear in NEXT F beam bridges are still unclear. In this paper, the lateral distributions of live load shear in NEXT F beam bridges were examined through a comprehensive parametric study. The parameters covered in this study included bridge section, span length, beam section, number of beams, and number of lanes loaded. A validated finite element (FE) modeling technique was employed to analyze the shear behavior of NEXT F beam bridges under the AASHTO HL-93 loading and to determine the LLDFs for shear in NEXT beam bridges. A method for computing the FE-LLDF for shear was proposed for NEXT beam bridges. Results from this study showed that the FE-LLDFs have a similar trend as the AASHTO LFRD-LLDFs. However, it was observed that some LRFD-LLDFs are lower than the FE-LLDFs by up to 14.1%, which implied using the LRFD-LLDFs for shear could result in an unsafe shear design for NEXT beam bridges. It is recommended that a factor of 1.2 be applied to the LRFD-LLDF for shear in NEXT F beam bridges for structural safety and design simplicity.

Longitudinal Load Distribution Factor of Helical Gears

1985 ◽  
Vol 107 (1) ◽  
pp. 17-22 ◽  
Author(s):  
T. Tobe ◽  
K. Inoue
Keyword(s):  
Load Distribution ◽  
Plate Theory ◽  
Bending Moment ◽  
Transverse Load ◽  
Alignment Error ◽  
Distribution Factor ◽  
Helical Gears ◽  
Longitudinal Load ◽  
Moment Distribution ◽  
Load Distribution Factor

This paper deals with the longitudinal load distribution and the bending moment distribution of a pair of helical gears with a known total alignment error. The load distribution along the contact lines is calculated by the finite element method based on the plate theory including transverse shear deformation. Empirical formulas for both longitudinal load distribution factor and bending moment distribution factor are proposed for practical use. The load distribution factor in AGMA 218.01 is examined, and it is concluded that the load distribution factor is close to the calculated results if the value of unity is taken as the transverse load distribution factor.

Self-launching erection machines for precast concrete bridges

PCI Journal ◽  
2010 ◽  
Vol 55 (1) ◽  
pp. 36-57 ◽  
Author(s):  
Marco Rosignoli
Keyword(s):  
Precast Concrete ◽  
Concrete Bridges

Reliability Analysis of Prestressed Concrete Bridges in Mexico: Assessment and Live Load Factors Proposal

2021 ◽  
Author(s):  
Rolando Salgado-Estrada ◽  
Sergio A. Zamora-Castro ◽  
Agustín L. Herrera-May ◽  
Yessica A. Sánchez-Moreno ◽  
Yair S. Sánchez-Moreno
Keyword(s):  
Reliability Analysis ◽  
Prestressed Concrete ◽  
Concrete Bridges ◽  
Live Load ◽  
Prestressed Concrete Bridges ◽  
Load Factors

ON THE EFFECT OF EFFORT REGULATION BY MEANS OF TEMPORARY CONTINUITYIN SPLIT SPAN STRUCTURES OF STEELREINFORCED CONCRETE BRIDGES

2021 ◽  
pp. 58-61
Author(s):  
I.Yu. Belutsky ◽  
◽  
I.V. Lazarev ◽  
Keyword(s):  
Reinforced Concrete ◽  
Bending Moment ◽  
Concrete Bridges ◽  
Stress Rate ◽  
Steel Reinforced Concrete ◽  
Reinforced Concrete Bridges ◽  
Effort Regulation

Abstract. The publication shows the effectiveness of applying the principle of temporary continuity by combining split span structures into acontinuous couplingusing a temporary joint. The method can be viewed as an option for effort regulation, creating abearing capacity reserveinload-bearing constructions within the span structures of bridges. The calculations provided show the effect on stress rate and bending moment in split span structurescombined into a double-spancontinuous coupling by a temporary joint.

scholarly journals Comparison of Induced Deflection and Forces in Piles Adjacent to Tunnelling and Deep Excavation in 2D and 3D Problems

2018 ◽  
Vol 203 ◽  
pp. 04011
Author(s):  
Ong Yin Hoe ◽  
Hisham Mohamad
Keyword(s):  
Bending Moment ◽  
Pile Group ◽  
3D Models ◽  
Deep Excavation ◽  
Pile Groups ◽  
Out Of Plane ◽  
National University ◽  
Plane Direction ◽  
2D And 3D ◽  
2D Model

There is a trend in Malaysia and Singapore, engineers tend to model the effect of TBM tunneling or deep excavation to the adjacent piles in 2D model. In the 2D model, the pile is modelled using embedded row pile element which is a 1-D element. The user is allowed to input the pile spacing in out-of-plane direction. This gives an impression to engineers the embedded pile row element is able to model the pile which virtually is a 3D problem. It is reported by Sluis (2014) that the application of embedded pile row element is limited to 8D of pile length. It is also reported that the 2D model overestimates the axial load in pile and the shear force and bending moment at pile top and it is not realistic in comparison to 3D model. In this paper, the centrifuge results of single pile and 6-pile group - tunneling problem carried out in NUS (National University of Singapore) are back-analysed with Midas GTS 3D and a 2D program. In a separate case study, pile groups adjacent to a deep excavation is modelled by 3D and 2D program. This paper compares the deflection and forces in piles in 2D and 3D models.

scholarly journals Study on Elastic Global Shear Buckling of Curved Girders with Corrugated Steel Webs: Theoretical Analysis and FE Modelling

2018 ◽  
Vol 8 (12) ◽  
pp. 2457 ◽  
Author(s):  
Kangjian Wang ◽  
Man Zhou ◽  
Mostafa Hassanein ◽  
Jitao Zhong ◽  
Hanshan Ding ◽  
...  
Keyword(s):  
Parametric Analysis ◽  
Trigonometric Function ◽  
Theoretical Formula ◽  
Radius Of Curvature ◽  
Buckling Strength ◽  
Shear Buckling ◽  
Curved Girders ◽  
Corrugated Steel Web ◽  
Orthotropic Shells ◽  
Elastic Shear

Despite the construction of several curved prestressed concrete girder bridges with corrugated steel webs (CSWs) around the world; their shear behavior has seldom been investigated. Accordingly, this paper substitutes the lack of available information on the global elastic shear buckling of a plane curved corrugated steel web (PCCSW) in a curved girder. This is based on the equilibrium equations and geometric equations in the elastic theory of classical shells, combined with the constitutive relation of orthotropic shells. Currently, the global elastic shear buckling process of the PCCSW in a curved girder is studied, for the first time in literature, with an equivalent orthotropic open circular cylindrical shell (OOCCS) model. The governing differential equation of global elastic shear buckling of the PCCSW, as well as its buckling strength, is derived by considering the orthotropic characteristics of a corrugated steel web, the rational trigonometric displacement modes, Galerkin’s method and variational principles. Additionally, the accuracy of the proposed theoretical formula is verified by comparison with finite element (FE) results. Moreover, the expressions of the inner or outer folded angle and radius of curvature are given by the cosine theorem of the trigonometric function and inverse trigonometric function. Subsequently, parametric analysis of the shear buckling behavior of the PCCSW is carried out by considering the cases where the radius of curvature is constant or variable. This parametric analysis highlights the effects of web dimensions, height-to-thickness ratio, aspect ratios of longitudinal and inclined panels, corrugation height, curvature radius and folded angles on the elastic shear buckling strength. As a result, this study provides a theoretical reference for the design and application of composite curved girders with CSWs.

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