Engineering Structures 101

Structural Engineering: From the Beginning

Professor Martin FaheyHead, School of Civil & Resource Engineering

Room A1.10(e-mail: fahey@civil.uwa.edu.au)

Cathedral of Notre Dame de Paris. 1150 -1220. Example of Gothic Architecture

Notre Dame de Paris. 1150 -1220.

Notre Dame de Paris

Notre Dame de Paris: North Rose Window.

Suspended in perfect equilibrium on a web of stone, the immense north rose window remains intact after 700 years, its intricately interlocking blocks so exact they ring when struck. Though individual blocks may be removed for repairs without collapsing the whole, only minor buckling has occurred

13 m

17 m

Notre Dame de Paris. Schematic sections showing the “flying butresses”

Decorative features on tops of columns (statues, pinnacles, as in

Notre Dame, below) have stabilising function

Construction of a Gothic cathedral

Bourges Cathedral, France, 1214. Most

efficient flying buttress system ever

constructed.

Sections through various French Gothic Cathedrals, showing progressive development

Amiens Cathedral, France, 1220.

Thrusts in flying buttresses (left) and structure of a groin

vault (above)

Dome: 3-dimensional equivalent of an arch.Pantheon, Rome, 118-128 AD. Temple to “all the gods”

Pantheon, Rome, 118-128 AD. Construction of the dome (concrete).

Interior of dome of Pantheon is semi- circular (hemispherical)

Outward thrust of the dome taken by 8 m thick composite heavy wall

Pantheon: Interior.Biggest clear span until 19th

century

Pantheon: Interior.Light provided by circular hole (“occulus”) in the top

Hagia, Sophia, Istanbul, 537 AD. Largest church for 9 centuries.

Hagia, Sophia, Istanbul, 537 AD. Interior, showing support

system for central dome

Hagia, Sophia, Istanbul, 537 AD. Schematic showing support system for central dome

Hagia, Sophia, Istanbul, 537 AD.

Comparison of sizes of various domes

Santa Maria del Fiore, Florence, Italy.

Begun in 1296. “Segmented dome”

added by Brunelleschi in 1436.

42 m span, 91 m high.

Built without “centering”

Santa Maria del Fiore, Florence, Italy.

Begun in 1296. Dome added by Brunelleschi

in 1436.

42 m span, 91 m high.

Built without “centering”

Shape is arch “a quinto acuto”

Dome of Santa Maria del Fiore, Florence, is not hemispherical, but is made up of 8 segments.

St Peter’s Basilica, Rome, Michaelangelo, 1546

Dome of St Peter’s Basilica, Rome, Michaelangelo, 1546

Interior of St Peter’s Basilica, Rome, showing

dome resting on four arches supported by four great

pillars

“Hanging chain” analysis of Dome of St Peter’s, by Giovani Poleni, 1742

Gateway Arch, St Louis, USA.

This free-standing arch is 630 ft. high and the world's tallest. Built of triangular section of double-walled stainless steel, the space between the skins being filled with concrete after each section was placed.

Looks like perfect “inverted catenary” shape.

Interior of Carmel Mission. Built in 1793 it is an interesting design in that the walls curve inward towards the top, and the roof consists of a series of inverted catenary arches built of native sandstone quarried from the nearby SantaLucia Mountains. (Carmel, California)

St Paul’s Cathedral, London (1675-1708). Christopher Wren

St Paul’s Cathedral Dome

St Paul’s Cathedral Dome

(3 domes inside each other)

Hooke’s “hanging chain” concept applied to the dome of Christopher Wren’s St Paul’s Cathedral. The “lantern” on top of

the dome distorts the “chain”

Sources

The pictures contained in this presentation were either downloaded from the Internet, or scanned in from books. The

sources are too numerous to list.