scholarly journals Investigation of Traffic Loading Effects for Different Codes on Medium- and Small-Span Girder Bridges in China

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Qingfei Gao ◽  
Biao Wu ◽  
Jun Li ◽  
Kemeng Cui ◽  
Chuang Xu
Keyword(s):  
Bridge Engineering ◽  
Traffic Load ◽  
Bending Moments ◽  
Original Design ◽  
Traffic Loading ◽  
Simply Supported ◽  
Girder Bridges ◽  
Loading Effects ◽  
Existing Bridges ◽  
Structure Evaluation

With increasing traffic volume, the traffic load grade given by design codes has gradually increased. For new bridges, there is no problem, and the traffic load can be met through the requirements of the new code. However, for existing bridges, there is a lack of uniform standards on whether they can continue to be used. It is not clear whether these bridges will be judged according to the new code or the original design code. The traffic loading effects of different codes on medium- and small-span girder bridges in China are investigated in this study. Three codes are introduced: JTJ 021-89, JTG D60-2004, and JTG D60-2015. Simply supported girder bridges and continuous girder bridges are discussed. The traffic loading effects calculated based on JTG D60-2015 are significantly larger than those calculated based on JTJ 021-89. For simply supported girder bridges, most of the differences range from 20% to 40%, and the maximum value is almost larger than 60%. For continuous girder bridges, most of the differences in the positive bending moments are concentrated in the 20%∼40% range, while the differences in the negative bending moments range from 10% to 20%. Therefore, the differences in traffic loading effects calculated based on various codes cannot be ignored in actual bridge engineering. The conclusion in this study can provide a basis for bridge structure evaluation and life prediction.

Traffic loads for the assessment of existing bridges

2021 ◽  
Author(s):  
Vazul Boros ◽  
Roman Lenner ◽  
Alan O'Connor ◽  
Andre Orcesi ◽  
Franziska Schmidt ◽  
...  
Keyword(s):  
Road Traffic ◽  
Traffic Load ◽  
Traffic Loading ◽  
Traffic Loads ◽  
Universal Solution ◽  
Load Effects ◽  
Characteristic Values ◽  
Existing Bridges ◽  
Partial Factor

<p>IABSE TG 1.3 aims to identify appropriate approaches for applications of the partial factor format in assessment of existing bridges. A sub-group was formed to investigate and provide recommendations on updating road traffic loads. Commonly, these are assessed by complex numerical simulations. While this study does not provide a universal solution, it demonstrates by a case study a simple and reasonably conservative way of using simulations to update traffic load effects, meanwhile continuously highlighting the objectives, potential alternatives or pitfalls of simulations. The results indicate that, for the short, single span bridge under consideration, the characteristic values given in Eurocodes provide conservative estimates. The probabilistic model for traffic loading obtained by bridge- and route-specific simulations will yield substantially more favourable reliability levels in comparison to the general model in fib Bulletin 80.</p>

Steel Bridge Load Rating Impacts Owing to Autonomous Truck Platoons

2020 ◽  
Vol 2674 (2) ◽  
pp. 57-67
Author(s):  
Rita Tohme ◽  
Matthew Yarnold
Keyword(s):  
The United States ◽  
Steel Bridge ◽  
Original Design ◽  
Screening Process ◽  
Vehicle Communication ◽  
Girder Bridges ◽  
State Highway ◽  
Steel Girder Bridges ◽  
Load Ratings ◽  
Existing Bridges

Autonomous truck platoons are two or more trucks driving together as a single unit through the use of vehicle-to-vehicle communication technology. These platoons can automatically accelerate or brake together, allowing them to travel at closer distances. With the world moving towards a more environment-friendly approach to everyday decisions, it is not a surprise that the concept of truck platooning is gaining momentum, as it reduces CO2 emissions by lowering fuel consumption. However, studies need to be performed to confirm that existing bridges will be able to adequately support truck platoons. The scope of this research is to study the effects of truck platooning on steel girder bridges in the United States (US). A multi-dimensional parametric study was conducted, which evaluated a variety of bridge span configurations and span lengths. Load ratings (using three different methodologies) were calculated for each of these structures for a range of truck platoons (both the number of trucks within a platoon and spacing between trucks). For comparison, the American Association of State Highway Transportation Officials (AASHTO) design and legal load ratings were also calculated for each bridge and were used to quantify the adequacy of current bridges to carry truck platoons. The study was able to identify the potentially inadequate existing bridges based on the original design methodology, configuration, and span length. This information is intended to be valuable to bridge owners as an initial screening process along corridors that will be subjected to regular truck platoon traffic.

Prestressing force increment of two-span steel girder

1991 ◽  
Vol 18 (2) ◽  
pp. 163-170 ◽  
Author(s):  
M. S. Troitsky ◽  
Z. A. Zielinski ◽  
N. F. Rabbani
Keyword(s):  
Virtual Work ◽  
Bending Moment ◽  
High Strength ◽  
Bridge Engineering ◽  
Advanced Technology ◽  
Steel Girder ◽  
Girder Bridges ◽  
Prestressing Force ◽  
Negative Bending ◽  
Existing Bridges

The economic advantages and the advanced technology of prestressed steel bridges has opened new opportunities in bridge engineering. The girder bridges prestressed by cables have been recognized as a technique for the design of new bridges as well as the rehabilitation and increasing the load-bearing capacity of the existing bridges. However, the prestressing of steel girders introduces new problems which require special attention and studies. The objective of this paper is to analyze the influence of the prestressing force increment and the induced negative bending moment in two-span steel girder bridges prestressed by external tendons (cables of high strength steel). The proposed analysis is based on the flexibility method. The deformations are calculated by the virtual work method. The analysis is limited to elastic stage only. The equations for calculating the prestressing force increment and the bending moment at the middle support are derived. Numerical examples are solved and the results are compared with those of similar non-prestressed girders. The influence lines are prepared and evaluated for a continuous girder of two equal spans of 60 m in length each. Key words: bridges, post-tensioned steel, force increment, analysis, influence line.

Large Deflection of a Rectangular Plate Resting on a Pasternak-Type Elastic Foundation

1977 ◽  
Vol 44 (3) ◽  
pp. 509-511 ◽  
Author(s):  
P. K. Ghosh
Keyword(s):  
Rectangular Plate ◽  
Elastic Foundation ◽  
Large Deflection ◽  
Lateral Load ◽  
Bending Moments ◽  
Shear Forces ◽  
Simply Supported ◽  
Base Parameters ◽  
Square Plate

The problem of large deflection of a rectangular plate resting on a Pasternak-type foundation and subjected to a uniform lateral load has been investigated by utilizing the linearized equation of plates due to H. M. Berger. The solutions derived and based on the effect of the two base parameters have been carried to practical conclusions by presenting graphs for bending moments and shear forces for a square plate with all edges simply supported.

Standardization of Three Efficient Footbridges: Von Mises, Monocontentio and Bicontentio Prototypes.

2021 ◽  
Author(s):  
Mario Guisasola
Keyword(s):  
Boundary Conditions ◽  
Structural Characteristics ◽  
Structural Behavior ◽  
Bending Moments ◽  
Variable Depth ◽  
Constant Depth ◽  
Simply Supported ◽  
Vertical Walls ◽  
Basic Concepts ◽  
Von Mises

<p>The Von Mises, Monocontentio and Bicontentio footbridges are three parameterized metal bridge whose main structural characteristics are their variable depth depending on the applied stress and the embedding of abutments. Its use is considered suitable for symmetrical or asymmetrical topographies with slopes or vertical walls on one or both edges. The footbridges include spans spaced apart by 20 to 66 meters, and are between 2 to 4.5 meters wide.</p><p>Its design is based on five basic concepts: integration in the geometry of the environment; continuous search for simplicity; design based on a geometry that emanates from structural behavior; unitary and round forms; and long- lasting details.</p><p>The structural behavior of these prototypes has been compared with three types of constant-depth metal beams: the bridge simply supported, and the bridge embedded on one or both sides.</p><p>The embedding of abutments, and the adoption of a variation of depth adapted to the bending moments diagrams, allow for more efficient and elegant forms which are well-adapted to the boundary conditions.</p>

scholarly journals Effect of Web Inclination on Box Girder Bridges

2020 ◽  
Vol 9 (12) ◽  
pp. 232-236
Keyword(s):  
Finite Element ◽  
Bridge Engineering ◽  
Easy Access ◽  
Finite Element Models ◽  
Box Girder Bridges ◽  
Box Girder ◽  
Class A ◽  
Girder Bridges ◽  
Live Loads ◽  
Support Reactions

Bridge is a key element in any transportation system which provides easy access over physical obstacles like road, valley, water bodies etc. without closing the way underneath. Among various types, use of box girder type bridges are gaining popularity in bridge engineering because of its better stability, serviceability, economy, aesthetics, structural efficiency and rigidity in torsion. In this study, a box girder is analyzed by changing its web inclination angle to the horizontal (90°, 83°, 76°, 69°, 62°) using finite element based software CSi Bridge. Finite element models are developed keeping material properties, span length, boundary conditions as constant parameters. All these models are analyzed for self-weight, including load of wearing coat and crash barrier, and live loads specified by Indian Road Congress (IRC) namely IRC Class 70R and IRC Class-A loading. Responses in terms of torsional moment, longitudinal moment, support reactions, displacement and stresses are determined.

scholarly journals Vehicle-Assisted Techniques for Health Monitoring of Bridges

Sensors ◽  
2020 ◽  
Vol 20 (12) ◽  
pp. 3460 ◽  
Author(s):  
Hoofar Shokravi ◽  
Hooman Shokravi ◽  
Norhisham Bakhary ◽  
Mahshid Heidarrezaei ◽  
Seyed Saeid Rahimian Koloor ◽  
...  
Keyword(s):  
Health Monitoring ◽  
Autonomous Vehicle ◽  
Highway Bridges ◽  
Traffic Load ◽  
Monitoring Methods ◽  
Conventional Vehicle ◽  
Weigh In Motion ◽  
Moving Vehicles ◽  
Existing Bridges ◽  
Future Work

Bridges are designed to withstand different types of loads, including dead, live, environmental, and occasional loads during their service period. Moving vehicles are the main source of the applied live load on bridges. The applied load to highway bridges depends on several traffic parameters such as weight of vehicles, axle load, configuration of axles, position of vehicles on the bridge, number of vehicles, direction, and vehicle’s speed. The estimation of traffic loadings on bridges are generally notional and, consequently, can be excessively conservative. Hence, accurate prediction of the in-service performance of a bridge structure is very desirable and great savings can be achieved through the accurate assessment of the applied traffic load in existing bridges. In this paper, a review is conducted on conventional vehicle-based health monitoring methods used for bridges. Vision-based, weigh in motion (WIM), bridge weigh in motion (BWIM), drive-by and vehicle bridge interaction (VBI)-based models are the methods that are generally used in the structural health monitoring (SHM) of bridges. The performance of vehicle-assisted methods is studied and suggestions for future work in this area are addressed, including alleviating the downsides of each approach to disentangle the complexities, and adopting intelligent and autonomous vehicle-assisted methods for health monitoring of bridges.

Dynamic Response of Simply-Supported Curved Girder Bridges due to Vehicles

2011 ◽  
Vol 255-260 ◽  
pp. 1825-1829
Author(s):  
Jian Qing Bu ◽  
Gen Wang Li
Keyword(s):  
Dynamic Response ◽  
Impact Factor ◽  
Torsion Angle ◽  
Radius Of Curvature ◽  
Vertical Deflection ◽  
Simply Supported ◽  
Girder Bridges ◽  
Bridge Model ◽  
Curved Girder Bridges ◽  
The Impact

The purpose of this paper, for which a finite element bridge model with 7 degrees of freedom per node and the 1/4 vehicle model with six parameters were established, is to analyze the dynamic response of curved girder bridges under vehicular loads. In the numerical simulation, the vibration characteristics of simply-supported curved girder bridge are analyzed, and the effect to the impact factors were also studied for different radiuses of curvature, eccentricities, ratios between bending and torsion stiffness, and vehicle speeds. The simulated results show that not all the first 5 natural frequencies increase with the variation of radius of curvature. The impact factor variations of vertical deflection and torsion angle are not uniform when parameters changed, and the impact factor of torsion angle would be much larger than that of vertical deflection under the same conditions.

End moments in open web steel joists

1980 ◽  
Vol 7 (1) ◽  
pp. 114-124
Author(s):  
S. C. Shrivastava ◽  
R. G. Redwood ◽  
P. J. Harris ◽  
A. A. Ettehadieh
Keyword(s):  
Significant Influence ◽  
The Other ◽  
Bending Moments ◽  
Axial Loads ◽  
Simply Supported ◽  
Gravity Load ◽  
Negative Bending

A study is made of the behaviour of open web steel joists having both top and bottom chords connected to a column when the end is subjected to negative bending moments. Six tests are described, three of which examine the behaviour with typical standard connections as detailed and supplied by manufacturers; the other three involve modifications to these connections in an attempt to minimize connection eccentricity. It is shown that the eccentricities inherent in the standard connections examined can have a significant influence on the behaviour and strength of a joist, whereas if the eccentricities are eliminated, reasonably predictable behaviour, based upon the member resistances under axial loads, can be achieved. These results are examined in relation to tie joists, which are designed to be simply supported under gravity load but have the bottom chord extended and attached to a column, and also in relation to joists designed as framing members.

Sign in / Sign up

Export Citation Format

Share Document