scholarly journals Impact of Traffic Load Randomness on Fatigue of Steel Bridges

2020 ◽  
Vol 15 (5) ◽  
pp. 21-44
Author(s):  
Adam Wysokowski
Keyword(s):  
Road Traffic ◽  
Steel Bridges ◽  
Traffic Load ◽  
Steel Bridge ◽  
Traffic Loads ◽  
Fatigue Durability ◽  
Vehicle Velocity ◽  
Bridge Structures ◽  
Heavy Goods Vehicles

The article considers the influence of the randomness of traffic load on the fatigue of elements of steel bridge structures. The phenomenon occurs specifically in the case of bridges characterized by significant width, with many traffic lanes and a high vehicle velocity, especially in the case of heavy goods vehicles. It has been shown that underestimation of operational durability, including fatigue durability, can be up to 23%. Operational loads increase due to the overlapping of traffic loads, which leads to the increased fatigue of elements of steel bridge structures. In an effort to assess this influence and its value, elements of the problem of the randomness of road traffic loads were compiled and described, and a simulative analysis of the operational strength of various lengths (spans) of the main girders of bridges was carried out. The analyses showed that for the structures with spans length of up to 10.0 m, the influence of passing vehicles could be skipped in calculations, especially in the case of weak traffic.

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>

Failure of Steel Bridges due to Constraint Induced Fracture

2016 ◽  
Vol 250 ◽  
pp. 61-68
Author(s):  
Paweł Grzegorz Kossakowski
Keyword(s):  
Steel Bridges ◽  
Steel Bridge ◽  
Factors Associated ◽  
The Us ◽  
Bridge Structures ◽  
Type Of Fracture

This paper discusses issues related to the failure of steel bridge structures attributable to a certain type of fracture called Constraint Induced Fracture (CIF). It focuses on the causes of and factors associated with this phenomenon as it has been responsible for the failure of several bridges in the last dozen years. The strength aspects of the CIF phenomenon are analyzed using the example of the failure of the Hoan Bridge over the Milwaukee River in the US.

Problems Connected with the Application of Lamella Flanges in Steel Bridge Construction

2015 ◽  
Vol 769 ◽  
pp. 13-18
Author(s):  
Vladimir Kristek ◽  
Jaromir Kunrt ◽  
Miroslav Skaloud ◽  
Shota Urushadze
Keyword(s):  
Steel Bridges ◽  
Cumulative Damage ◽  
The Other ◽  
Steel Bridge ◽  
Bridge Construction ◽  
Simple Assumption ◽  
Bridge Structures ◽  
Damage Process ◽  
Perfect Contact ◽  
Pure Compression

Lamella flanges (Fig. 1) have lately grown popular with the designers of steel bridges –in their belief that these flanges provide us with the possibility of avoiding very thick flange plates in steel bridge structures. This belief is based on the assumption that the lamellas are perfectly plane and, therefore, in perfect contact everywhere, so that the loading from one lamella is transmitted into the other via pure compression, and that the perfect interaction of both lamellas is materialized by means of boundary fillet welds connecting both of the two lamellas. This simple assumption is, however, far from reality: it is not in the means of steel fabricators, not even in the means of those which are very progressively equipped, to produce perfectly plane flange lamellas. Then both lamellas exhibit unavoidable initial curvatures, which in combination form a gap between the lamellas, and consequently the directly loaded lamella is pressed into this gap. As the loading acting on every bridge is many times repeated, the aforesaid phenomenon is also many times repeated, (we can say that the lamellas „breathe“), and then an unavoidable cumulative damage process in the lamellas comes to being.

scholarly journals Quality Control of the Anchoring of Steel Bridge Barriers by Non-Destructive Testing

Safety ◽  
2020 ◽  
Vol 6 (1) ◽  
pp. 2
Author(s):  
Tereza Komárková ◽  
Jaromír Láník ◽  
Anton Ondřej
Keyword(s):  
Road Safety ◽  
Traffic Accidents ◽  
Road Traffic ◽  
Pulse Method ◽  
Ultrasonic Pulse ◽  
Steel Bridge ◽  
Destructive Testing ◽  
Bridge Structures ◽  
Safety Features ◽  
Non Destructive

Traffic barriers represent one of the basic road safety features. There are several types of traffic barriers based on the material from which they are made of and their location. Bridge structures are usually fitted with steel barriers. A steel barrier is, in fact, a relatively complex system linking individual steel elements, which, as a whole, has to meet the requirements given by normative regulations. In order for the steel barriers to fulfill their function and prevent the catastrophic consequences of traffic accidents, it is absolutely necessary to ensure their correct installation on the bridge structure. It seemed until recently that carrying out quality inspections of steel barriers installation, i.e., their anchoring into the concrete ledges, was a relatively complicated time- and money-consuming process, and that is why inspections of the correct anchoring installation in new or existing barriers were not carried out as standard. This paper thoroughly describes in detail the non-destructive ultrasonic pulse method, with which the anchoring of steel barriers on selected bridge structures is being checked. From the measurements and statistical evaluation of the results, it is apparent that carrying out inspections of the anchoring of these road safety features should be considered routine, and at the same time, the inspection of anchoring quality should be required by law in order to ensure the safety of road traffic.

scholarly journals Review of annual progress of bridge engineering in 2019

2020 ◽  
Vol 1 (1) ◽  
Author(s):  
Renda Zhao ◽  
Yuan Yuan ◽  
Xing Wei ◽  
Ruili Shen ◽  
Kaifeng Zheng ◽  
...  
Keyword(s):  
High Performance ◽  
Concrete Bridges ◽  
Bridge Engineering ◽  
Research Progress ◽  
Steel Bridge ◽  
Wind Resistance ◽  
Main Research ◽  
Bridge Model ◽  
Bridge Evaluation ◽  
Bridge Structures

AbstractBridge construction is one of the cores of traffic infrastructure construction. To better develop relevant bridge science, this paper introduces the main research progress in China and abroad in 2019 from 13 aspects, including concrete bridges and the high-performance materials, the latest research on steel-concrete composite girders, advances in box girder and cable-supported bridge analysis theories, advance in steel bridges, the theory of bridge evaluation and reinforcement, bridge model tests and new testing techniques, steel bridge fatigue, wind resistance of bridges, vehicle-bridge interactions, progress in seismic design of bridges, bridge hydrodynamics, bridge informatization and intelligent bridge and prefabricated concrete bridge structures.

Analysis of Vehicle–Pedestrian Interactive Behaviors near Unsignalized Crosswalk

2021 ◽  
pp. 036119812199906
Author(s):  
Byeongjoon Noh ◽  
Dongho Ka ◽  
David Lee ◽  
Hwasoo Yeo
Keyword(s):  
South Korea ◽  
Traffic Accidents ◽  
Road Traffic ◽  
The Road ◽  
Video Footage ◽  
Premature Deaths ◽  
Vehicle Velocity ◽  
Behavioral Features ◽  
Velocity Changes ◽  
On The Road

Road traffic accidents are a leading cause of premature deaths and globally pose a severe threat to human lives. In particular, pedestrians crossing the road present a major cause of vehicle–pedestrian accidents in South Korea, but we lack dense behavioral data to understand the risk they face. This paper proposes a new analytical system for potential pedestrian risk scenes based on video footage obtained by road security cameras already deployed at unsignalized crosswalks. The system can automatically extract the behavioral features of vehicles and pedestrians, affecting the likelihood of potentially dangerous situations after detecting them in individual objects. With these features, we can analyze the movement patterns of vehicles and pedestrians at individual sites, and understand where potential traffic risk scenes occur frequently. Experiments were conducted on four selected behavioral features: vehicle velocity, pedestrian position, vehicle–pedestrian distance, and vehicle–crosswalk distance. Then, to show how they can be useful for monitoring the traffic behaviors on the road, the features are visualized and interpreted to show how they may or may not contribute to potential pedestrian risks at these crosswalks: (i) by analyzing vehicle velocity changes near the crosswalk when there are no pedestrians present; and (ii) analyzing vehicle velocities by vehicle–pedestrian distances when pedestrians are on the crosswalk. The feasibility of the proposed system is validated by applying the system to multiple unsignalized crosswalks in Osan city, South Korea.

Study on Influences of Thickness of Flange of U Rib on Mechanical Behaviors of Orthotropic Monolithic Steel Bridge Deck System

2010 ◽  
Vol 163-167 ◽  
pp. 122-126 ◽  
Author(s):  
Ru Deng Luo ◽  
Mei Xin Ye ◽  
Ye Zhi Zhang
Keyword(s):  
Finite Element Analysis ◽  
Yangtze River ◽  
High Speed ◽  
Bridge Deck ◽  
Steel Bridges ◽  
Engineering Practice ◽  
Steel Bridge ◽  
Mechanical Behaviors ◽  
Element Analysis ◽  
High Speed Railway

Orthotropic monolithic steel bridge deck system stiffened by U rib is very fit for high-speed railway steel bridges because of its excellent mechanical behaviors. Thickness of flange is a very important parameter of U rib and has influence on mechanical behaviors of orthotropic monolithic steel bridge deck system. Based on the engineering practice of Anqing Yangtze River Railway Grand Bridge, the kind and the extents of influences of thickness of flange of U rib on mechanical behaviors of orthotropic monolithic steel bridge deck system are studied with finite element analysis. The results show that thickness of flange of U rib has relative large positive influences on rigidity, strength and stability of orthotropic monolithic steel bridge deck system. 14~18mm is the appropriate range of thickness of flange of U rib for high-speed railway steel bridges.

Lastannahmen im Brückenbau – Vergleich von Verkehrslasten für Eisenbahnbrücken aus Lastmodellen und Messdaten/Actions on bridges – A comparison of traffic loads for railway bridges from traffic load models and measured data

Bauingenieur ◽  
2016 ◽  
Vol 91 (10) ◽  
pp. 410-416
Author(s):  
Gerhard Lener ◽  
Johannes Schmid
Keyword(s):  
Measured Data ◽  
Traffic Load ◽  
Railway Bridges ◽  
Load Models ◽  
Traffic Loads

Sowohl bei der ursprünglichen Dimensionierung als auch bei allfälligen Sanierungsvorhaben bedingen die Einwirkungen aus Verkehrslasten die Bauteilabmessungen maßgeblich. In vielen Fällen sind ältere Tragwerke nach heutigen Bemessungsrichtlinien deutlich unterdimensioniert, wodurch im Falle von Erweiterungsmaßnahmen zusätzliche Verstärkungsmaßnahmen im Bestand anfallen. Des Weiteren ist die Beurteilung der Restlebensdauer solcher Tragwerke in der Praxis schwierig, da in der Regel keine Informationen hinsichtlich der realen Einwirkungen aus Verkehrslasten vorhanden sind. Durch diesen unbefriedigenden Zustand motiviert, erfolgt in diesem Beitrag eine nähere Untersuchung realer, messtechnisch erfasster Einwirkungen auf Eisenbahnbrücken. Diese bilden die Basis für Vergleiche der Auswirkungen realer Messdaten und normativen Lastmodellen, die rechnerisch an unterschiedlichen Tragsystemen gezeigt werden. Dabei sind die im Vergleich zu den genormten Belastungen doch maßgeblich geringeren Einwirkungen deutlich erkennbar und liefern damit möglicherweise die Antwort auf die Frage, warum einzelne Eisenbahnbrücken nach wie vor funktionieren, obwohl deren rechnerische Lebensdauer bereits erreicht ist. Des Weiteren zeigt sich das daraus resultierende Optimierungspotenzial bei der Aktivierung von Realtragreserven beziehungsweise der deutlich höherer anzusetzender Lebenserwartung bestehender Tragwerke.

scholarly journals A New Approach of Smart Mobility for Heavy Goods Vehicles in Casablanca

2021 ◽  
Author(s):  
Mohammed Mouhcine Maaroufi ◽  
Laila Stour ◽  
Ali Agoumi
Keyword(s):  
Environmental Sustainability ◽  
Traffic Congestion ◽  
Traffic Management ◽  
Road Traffic ◽  
Smart Cities ◽  
Research Work ◽  
Transport Infrastructure ◽  
Transport Systems ◽  
Smart Mobility ◽  
Heavy Goods Vehicles

Managing mobility, both of people and goods, in cities is a thorny issue. The travel needs of urban populations are increasing and put pressure on transport infrastructure. The Moroccan cities are no exception and will struggle, in the short term, to respond to the challenges of the acceleration of the phenomenon of urbanization and the increase in demand for mobility. This will inevitably prevent them from turning into smart cities. The term smart certainly alludes to better use of technologies, but smart mobility is also defined as “a set of coordinated actions intended to improve the efficiency, effectiveness and environmental sustainability of cities” [1]. The term mobility highlights the preponderance of humans over infrastructure and vehicles. Faced with traffic congestion, the solutions currently adopted which consist of fitting out and widening the infrastructures, only encourage more trips and report the problem with more critical consequences. It is true that beyond a certain density of traffic, even Intelligent Transport Systems (ITS) are not useful. The concept of dynamic lane management or Advanced Traffic Management (ATM) opens up new perspectives. Its objective is to manage and optimize road traffic in a variable manner, in space and in time. This article is a summary of the development of a road infrastructure dedicated to Heavy Goods Vehicles (HGV), the first of its kind in Morocco. It aims to avoid the discomfort caused by trucks in the urban road network of the city of Casablanca. This research work is an opportunity to reflect on the introduction of ITS and ATM to ensure optimal use of existing infrastructure before embarking on heavy and irreversible infrastructure projects.

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