Slide 1: STEEL ARCHES AND
VAULTS Slide 2: STEEL ARCHES
Subject: Arches are structures curved in elevation, which carry vertical loads to the supports by compressive action in the arch-rib. Their main application is in bridges and large span roofs of buildings. Bridges and buildings may be built with single freestanding arch-ribs for which out-of-plane stability is the dominant design criterion. For these structures, the behavior is not fully understood and design rules are not available in the literature to determine the out-of-plane stability. Slide 3: ADVANTAGES OF STEEL ARCHES
Clear Span Space - No poles, no beams and no trusses! Easy "do-it-yourself" construction, usually erected in 2-5 days with no special equipment!
Maintenance Free! No termite worries, fire-resistant - steel doesn't burn! Painting? Why? Our buildings are Galvalume Steel which has a light dove gray sheen and carries a 25-year warranty.
Expandable! You won't have to rip out walls and put on costly additions. Just bolt on more 2' arches to add to the length of your building. Yes, it's that easy!
Affordable! There's not a building on the market that can compare to the quality of a US Building at a comparable price! Period!
Double overlap panel construction connected by two rows of bolts. It's the equivalent of a header beam every two feet! Unbeatable strength at a fraction of the cost of traditional buildings! Slide 7: EXAMPLES…… Slide 12: Prestressed Steel Arch Bridge Slide 13: INTRODUCTION
Arch bridges are amongst the oldest man made bridges. It is a most efficient structural form that is both striking in appearance and aesthetic in character. In a bid to further optimize the use of the arch profile, so as to arrive at a more economical arch bridge design, a new type of bridge called the .prestressed steel arch bridge. has been proposed. This paper discusses its salient
features in respect of design and construction.
Developing a bridge of a new type is a creative challenge as well as a technological one. Lin1 has stated that .such creativity generally comes about when the planned and synthesized applications of the available materials,
equipment, experience and theories of structural behaviour meet the environmental and construction requirements of the particular crossing.. Slide 14: STRUCTURAL ADVANTAGES
The new design offers comprehensive advantages which may be summarized as:
(1) Prestressing of structural steel increases the strength of the structure leading to a more economical design.
(2) Slender arch rib elements lead to significant advantages in handling and transportation.
(3) Reduced depth of structure for comparable spans, thereby reducing approach . roadway costs for the large number of overpasses.
(4) Lighter structure reducing the inertia effects induced by seismic events.
(5) Greater economies can be achieved when design is used with high strength and weather resistant steels.
(6) The bridge has exceptional grace and beauty and neatly expresses its Slide 16: EXAMPLES…… Slide 17: MIAMI INTERNATIONAL AIRPORT Slide 18: INTRODUCTION:
MIAMI INTERNATIONAL AIRPORT’S NEWEST CONCOURSE
FEATURES A VAULTED STEEL STRUCTURE—PROVIDING BOTH THE ROOF AND WALLSTRUCTURES—THAT POSED SIGNIFICANT DESIGN CHALLENGES.
Construction of “Concourse J,” which began September 2002 at the southeastern tip of the airport’s main terminal, is expected to be completed by the end of summer 2006.
The $100 million project is part of $4.5 billion airport expansion and renovation. Concourse J, which will complete the main terminal’s southern expansion, features 15 gates and a 340,000 sq. ft facility that measures approximately 840’ by 120’ on seven levels. Slide 19: MODEL VIEW OF THE AIRPORT VAULT DETAILS : VAULT DETAILS The use of steel construction was necessary to support the concourse’s complex architectural design.
The roof starts from the third floor, on the west side, and ends at the second floor, on the east side, of the building.
Curved steel rib members are used to form the steel roof shell, which functions as both the roof and walls of the building.
The roof is supported by primary curved rib members and curved roof trusses which are spaced 30’ on center.
These wide-flange, built up steel rib members vary in flange depth, tapering from 33” at
the top of the vault to 12” at the second floor.
The steel roof shell was connected to 1½” steel deck at the top of the filler beams and to the steel angle bracing at the bottom of the filler beams.
The structure was designed to transfer wind uplift to the primary members, which are spaced 30’ on center.
On its south end, the shell structure cantilevers 36’—another challenging aspect of the design. Slide 21: On its south end, the shell structure cantilevers 36’. Vertical bow truss supports composed of 6” round sections extend from the second floor to the bottom of the vaulted roof.