April 2011 – Civil Engineering Projects

Alamillo Bridge by Calatrava | Suspended Structures

April 11, 2011 by Designer

Alamillo Bridge, Seville, Spain | Suspended Structures

In my previous article, we discussed the development of Suspended Structures and the technical aspects involved in the construction of Suspended Structures.

Alamillo Bridge, Seville, Spain, 1987-1992, designed by Calatrava Santiago, total span of the bridge is 250m and height of the tower is 142m. Materials used are steel for tower with concrete infill where needed, steel bridge deck structure and concrete abutments. The extraordinary weight of the concrete filled steel mast, which angles away from the roadbed at 58 degrees is enough to support the deck without the need for counter-stay cables or support piers.

Alamillo Bridge, Seville, Spain | Suspended Structures

The mass and the bed of the tower exerts a backwards downward force while the cable stays and roadbed mass exert a forward downward force. The mass of the tower was so calculated so that its backward and downward force wouldn’t lift the bridge off the ground.

For this reason, an additional mass was needed to counter the reaction of vertical forces. In order to increase the mass, the steel box girder of the tower and the steel deck structure were filled with concrete. This added to the stability of the structure.

Development of Suspended Structures | Structural Systems

April 10, 2011 by Designer

Suspended Structures | Structural Systems

Suspended Structures are those with horizontal planes i.e. floors are supported by cables (hangers) hung from the parabolic sag of large, high-strength steel cables. The strength of a suspended structure is derived from the parabolic form of the sagging high strength cable.

To make this structure more efficient, the parabolic form is so designed that its shape closely follows the exact form of the moment diagrams.

The sagging cable is more stable under symmetrical loading conditions as the cable may deform as it attempts to adjust to an eccentric loading. As the cable adjusts to this load its shifts the rest of the structure.

This adjustment causes secondary stresses in the horizontal surface and additional deformation. The parabolic curve of the cable is also designed for various eccentric or lateral loads such as wind, seismic etc.

The large curving cable may consist of many smaller cables which are tightly spun together. As the cables are being spun together, they are also stretched over the span and attached to the supports.

Prefabricated Construction and Lightweight building systems

April 4, 2011 by Designer

Prefabricated Construction and Lightweight building systems

What is Prefabrication?

Prefabrication is the practice of assembling components of a structure in a factory or other manufacturing site, and transporting complete assemblies or sub-assemblies to the construction site where the structure is to be located. The term is used to distinguish this process from the more conventional construction practice of transporting the basic materials to the construction site where all assembly is carried out.

During the development in the industrial revolution, the people have full awareness regarding the behaviour of the structure.

It was fully analyzed and understood that for the existence of an object and its form, it is necessary that the object can bear all forces which act on it.

The structure thus, functions in three subsequent operations:

Load reception
Load transfer
Load discharge

The flow of forces does not pose problem as long as the object form follows the direction of acting forces. With these analytical theories of structure and at the same time new technological developments like prefabricated construction influence the designer.

In the works of Buckminster Fuller and Moshe Safdie, there is extensive use of fabricated components.

Deconstructivism | Walt Disney Concert Hall

April 3, 2011 by Designer

Deconstruction in Architecture

Deconstructivism in architecture is a development of postmodern architecture that began in the late 1980s.

Characteristics of Deconstructivism:

Fragmentation
Non linear processes of design
Apparent non-Euclidean geometry

The building designing is dependent upon the construction technology, majority of functions are streamlined and computers are playing the major role in it. It mainly covers the designing of multidirectional ambiguous spaces and forms creating optical illusion.

The basic concept project is to give the look of a ship with its sail at full mast and the designer wanted to create the feeling of square-foot Concert Hall having 2,265-seat auditorium with natural lighting in which the audience surrounds the orchestra.

The auditorium has a curved wooden ceiling which fulfils the acoustical requirements. The dramatically curved exterior of Walt Disney Concert Hall is clad in 22 million pounds of primary steel joined out of 12,500 individual pieces that range from 13 inches to 110 feet long.