Pont à haubans

Résumé

Les ponts à haubans sont un type de pont dont le tablier est suspendu par des câbles, eux-mêmes étant soutenus par des pylônes. thumb|Le pont de l'Iroise à Brest. Technique générale Contrairement aux ponts suspendus, qui tiennent grâce à deux câbles principaux ancrés sur les rives, les ponts à haubans tiennent grâce à de nombreux câbles obliques partant d'un pylône supportant le tablier qui supportera en fin de compte tout le poids du pont. Il constitue une avancée par rapport au pont suspendu sur les sols meubles, mais cependant limitée par la portée moindre du pont à haubans. Les ponts à haubans ont effectivement de moins grandes portées que les ponts suspendus car les piliers où sont rattachés les haubans doivent être élevés, et par conséquent, plus fragiles et plus vulnérables au vent et aux vibrations engendrées par la circulation. Les très grandes portées ne vont actuellement pas au-delà de , bien que les experts considèrent qu’il serait possible de construire des

Source officielle

À propos de ce résultat

Cette page est générée automatiquement et peut contenir des informations qui ne sont pas correctes, complètes, à jour ou pertinentes par rapport à votre recherche. Il en va de même pour toutes les autres pages de ce site. Veillez à vérifier les informations auprès des sources officielles de l'EPFL.

Publications associées

Chargement

Personnes associées

Chargement

Unités associées

Chargement

Concepts associés

Chargement

Cours associés

Chargement

Séances de cours associées

Chargement

Excessive self-weight and difficulty in construction are the main issues confronted by super-long-span arch bridges. To address these issues, a conceptual design of steel-ultra-high performance fibre-reinforced concrete (UHPFRC) composite truss arch bridge with a main span of 1000 m was proposed, and the corresponding structural responses were numerically investigated based on finite element analysis (FEA) in this study. In this proposal, the UHPFRC was applied to box arch ribs for bearing the large axial forces, and the steel was used for web members and transversal connectors to avoid the risk of cracking. Such composite arch bridge has a much lower self-weight than traditional concrete arch bridges and avoids the need for welding on thick steel plates since only thin steel elements (thickness not exceeding 40 mm) are used compared to steel arch bridges. The cantilever erection with cables support was adopted during the main arch erection. In this scope, the temporary erection cables merely need to bear the self-weight of two truss arches and the transversal connectors during each closure and the process is repeated four times, which thus reduces largely the cost of temporary supports for construction and increases the feasibility of the construction. Based on the FEA results, the UHPFRC arch ribs are always in compression at a maximum compressive stress of 63.8 MPa. Furthermore, the stability, stress, and stiffness of each component during each construction stage meet the requirements of the code. By the comparative studies of the steel arch bridges, UHPFRC arch bridges, and the proposed one, the steel-UHPFRC composite truss arch bridge has significant technical and economical advantages and is suitable for a bridge with a main span in the range of 500 similar to 1000 m.

ELSEVIER SCI LTD2021

Chargement

Fatigue Damage Factor Calibration for Long-Span Cable-Stayed Bridge Decks

José Joaquim Costa Branco de Oliveira Pedro, Alain Nussbaumer, Cláudio Alexandre Pereira Baptista

Part 2 of the Eurocode 3 (EN 1993-2) proposes a straight forward fatigue verification method using a single heavy vehicle model (FLM3) and a damage equivalent factor, lambda, to represent the fatigue damaging effects of the real traffic on road bridges. The method is very appealing for bridge design. However, the lambda-factor has limitations and is not defined in the EN1993-2 for some load cases or "span lengths" above 80 m, renamed here as "critical lengths". This is the case of cable-stayed bridge decks, where a combination of two internal forces-bending and compression (induced by the stays)-is a characteristic of this bridge system, and stay-cables, with specific shapes of influence lines. To address the above issues a variant solution of the Vasco da Gama Bridge is taken as the case study. In this paper, the results of the lambda-factor computed for different critical lengths are compared with previous studies and the original work that led to the current EN formulas for lambda. Based on these results, a constant lambda value for critical lengths above 80 m is proposed to update the EN for the "mid-span case". For the fatigue design of stays and steel girders, recommendations are given for determining the critical length based on the influence line of the bending moments.

SPRINGER NATURE SWITZERLAND AG2019

Chargement

Experimental investigation on the load-carrying capacity of thin webs including post-tensioning tendons

Miguel Fernández Ruiz, Eckart Hars, Aurelio Muttoni

The presence of post-tensioning tendons in webs decreases the load-carrying capacity of the compression struts that are necessary to transfer shear forces. This effect has been known for a long time, but was initially not included in design codes. In particular, older bridge designs often included fairly large ducts in rather thin webs. This paper presents the results of an extensive experimental investigation on the effect of the presence of post-tensioning ducts on the shear capacity of thin-webbed post-tensioned girders. The study included a series of large-scale tests performed in the laboratory on post-tensioned girders extracted from an existing bridge.

fib Symposium, Dubrovnik 20072007

Chargement