21 research outputs found
The Effect of Lane Changing on Long-Span Highway Bridge Traffic Loading
No full textBridge Maintenance, Safety, Management, Resilience & Sustainability, Sixth International IABMAS Conference, Stresa, Lake Maggiore, Italy, 8-12 July 2012Maximum loading on long-span bridges typically occurs in congested traffic conditions. As
traffic becomes congested car drivers may change lane, increasing the tendency for trucks to travel in platoons.
For long-span bridges this phenomenon may increase the regularity and severity of bridge repair programs,
with potential significant associated costs. This research investigates the effect of lane changing by car
drivers on bridge loading. A Monte Carlo simulation model in which individual car drivers probabilistically
decide, based on a lane-changing bias probability, whether or not to change lane has been developed. The
sensitivity of bridge loading to this factor is investigated for different bridge lengths and traffic compositions.
This research concludes that the lane-changing behavior of car drivers has an effect on bridge loading for
long-span bridges, and the magnitude of this effect is quite sensitive to the percentage of trucks in the traffic.Deposited by bulk impor
The structural reliability of bridges subject to time-dependent deterioration
No full textPaper presented at the 11th International Conference on Civil, Structural and Environmental Engineering Computing, Malta, 18-21 September 2007The reliability of the structural performance of any given structure is affected by both in-service loading and material deterioration due to environmental attack. They must be evaluated at any given time in order to compute lifetime probability of failure. This paper presents an innovative methodology to derive the structure lifetime load effect due to existing traffic using a statistical tool known as Predictive Likelihood. Loss of resistance due to corrosion originated by chloride ingression is also taken into account. Finally the lifetime probability of failure is evaluated via the application of a time-discretization strategyNot applicableConference detailshttp://www.civil-comp.com/conf/cc07.htmConference website at http://www.civil-comp.com/conf/cc07.htm. Record must include a full reference to the published paper and a DOI weblink to the final published version - http://dx.doi.org/10.4203/ccp.86.189. DG
06/07/10
au,ti, ke - AL 23/07/201
Using Instrumented Vehicles to Detect Damage in Bridges
No full textThis paper describes a ‘drive-by’ method of bridge inspection using an instrumented vehicle. Accelerometers on the vehicle are proposed as a means of detecting damage on the bridge in the time it takes for the vehicle to cross the bridge at full highway speed. For a perfectly smooth road profile, the method is shown to be feasible. Changes in bridge damping, which is an indicator of damage, are clearly visible in the acceleration signal of a quarter-car vehicle on a smooth road surface modelled using MatLab. When road profile is considered, the influence of changes in bridge damping on the vehicle acceleration signal is much less clear. However, when a half-car model is used on a road with a rough profile, it is again possible to detect changes in bridge damping, provided the vehicle has two identical axles
Using instrumented vehicles to detect damage in bridges
No full text15th International Conference on Experimental Mechanics, Porto, Portugal, 22-27 July 2012, Paper No. 2934Bridge structures are subject to continuous degradation due to the environment, ageing and excess loading. Monitoring of bridges is a key part of any maintenance strategy as it can give early warning if a bridge is becoming unsafe. This paper will theoretically assess the ability of a vehicle fitted with accelerometers on its axles to detect changes in damping of bridges, which may be the result of damage. Two vehicle models are used in this investigation. The first is a two degree-of-freedom quarter-car and the second is a four degree-of-freedom halfcar. The bridge is modelled as a simply supported beam and the interaction between the vehicle and the bridge is a coupled dynamic interaction algorithm. Both smooth and rough road profiles are used in the simulation and results indicate that changes in bridge damping can be detected by the vehicle models for a range of vehicle velocities and bridge spans.Deposited by bulk importkpw12/2/1
Statistical computation for extreme bridge traffic load effects
No full textEighth International Conference on Computational Structures Technology, Las Palmas de Gran Canaria, Spain, from 12 to 15 September 2006The maintenance of highway infrastructure constitutes a major expenditure in many
countries. This cost can be reduced significantly by minimizing the repair or
replacement of highway bridges. In the assessment of existing bridges, the strength
estimate tends to be more accurate than that of traffic loading, due to the more
variable nature of loading. Recent advances in the statistical analysis of highway
bridge traffic loading have resulted in more accurate forecasts of the actual loading
to which a bridge is subject. While these advances require extensive numerical
computation, they can significantly improve the accuracy of the calculation. This
paper outlines the recent advances and describes the associated computational
aspects in detailDeposited by bulk importkpw26/2/1
Effect of operating temperature on the dynamic properties of a pultruded GFRP footbridge
No full textLe quartier transitoire ou la manière de nommer une confoncture socio-spatiale dans le cadre d'un quartier ethnique de centre-ville
No full textwww.geographicahelvetica.unibas.chInternational audienceThe way of naming a district with ethnic connotation is often linked to the residential and economic statute of the immigrant populations. Moreover the various terminology, which refers to it, differs according to the author but also according to the geographical situation of urban spaces. This article proposes a different manner to approach the districts located in downtown area, combining at the same time a geographical and sociological approach phenomenon. It seems necessary to take into account the way of establishment of these populations as well as the frequentation of the district in the development of its definition.La manière de nommer un quartier à connotation ethnique est souvent tributaire du statut résidentiel et économique qu'occupent les populations immigrées et issues de l'immigration. La terminologie variée, qui s'y réfère, diffère par ailleurs selon l'auteur, mais également selon la situation géographique de l'espace urbain. Cet article propose une manière différente d'aborder les quartiers situés en centre-ville, alliant à la fois une approche géographique et sociologique du phénomène. Il apparaît ainsi indéniable de prendre en considération le mode d'installation de ces populations ainsi que la fréquentation du quartier dans l'élaboration de sa définition
