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BRIDGE AESTHETICS

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 BRIDGE AESTHETICS
(CASE OF SCIENCE TAKEN TO THE LEVEL OF ART)

V.N. Heggade presently is Sr Vice President & Member, Board of

Management of Gammon India Limited. He has more than 31 years of
experience of Designing and Constructing Bridges, Energy structures like
Chimneys & Cooling towers, Marine structures and Hydraulic structures

Association Of Bridge & Structural Engineers, Switzerland) from

developing countries in addition to National awards like Pt Jawaharlal
Nehru Centenary award from IRC; Pre stressed concrete design award
from Institution of Engineers, and ICI awards for best publications.
V.N. HEGGADE He has more than 90 papers to his credit and is a member of various
Sr. Vice President & Member IRC (Indian Roads Congress) and BIS (Bureau of Indian Standards)
Board of Management committees. He is also a member of Indian Member Committee of
Gammon India Limited, Mumbai
venkat.heggade@gammonindia.com a keynote speaker in National and International Seminars, Symposiums
and Congresses. He has a passion for tall and long structures and he is an
ardent advocate of sustainability and aesthetics in construction.

Summary 1. Introduction
Bridges being subjected aesthetic treatment is a
recent phenomenon of perhaps since a century. There claddings and other ornamentations not exposing the
has been a fascinating debate across as to whether structural design while the bridges being devoid of
bridge aesthetics is an art or a science. There has such embellishments expose the structural design
been evidence of aesthetics of artifacts and art being nakedly to beholders. It is obvious to the observers
subjected to mathematicisation in the form of Golden
section rules in which the art and art forms are related

Indian context before Christ era (BC), the structures approach is often to integrate the buildings into the
especially temples were built on the principles of ambience, local culture, etc. despite the demerits of
Vastupurushamandala (Divine Square) and the art the building’s structural form whereas the engineering
particularly music short and long syllable conformed approach to bridge design is quite often to consider a
to Fibonacci series whose limiting ratio is 1.618. bridge as an abstract structural form independent of
Apart from this, there also have been views that in its ambience.
case of bridges, the mere principle of ‘Form Follows
Forces’ is adequate for aesthetic elegance.
The paper discusses, the various issues including
controversial ones as above relating to bridge

ethical obligation to our posterity to leave behind

the memorable bridges as our predecessors left us
with memorable mandirs, mahals, masjids, churches,
cathedrals and castles.
Key Words: Aesthetics, Creativity, Idiosyncrasy,
Form Following Forces. Mathematicisation, Golden
section rules. Fig. 1: Root bridges of India

42 Volume 45 Number 3 September 2015 The Bridge and Structural Engineer

The Architecture is arrangement of abstract and our past by beautiful mandirs, (Temples) masjids
visual forms while constructing artifacts for practical, (Mosques) and mahals (Palaces), our posterity should
aesthetic and symbolic purposes that exist in space remember us by the bridges, we create.
and which are experienced by walking through it.
It is unthinkable to propose an argument that any
Architects address Functions, Forms and Structures,
engineer wants his bridge to be unpleasant and
without necessarily giving meaningful expressions
ugly. But still aesthetics that is invariably a result of
to loads, equilibrium and forces. The Aesthetics is a
creativity remains mysterious as most of the times
perception and the experience of human sensibilities
engineers’ creativity is channelised only to achieve
as a response to overall culmination of visual form.
In the literature, there is no evidence to the fact that codal stipulations. There is an urgent need for the
bridges being considered for the aesthetic treatment rulers to create an environment to nurture and nourish
till the middle of 18th century. Till the time of the the aesthetic idiosyncrasies apart from economy and
inception of engineering establishments including mediocrity by removing impediments in contractual
military engineering establishment in Paris around and codal stipulations
1750, bridges were considered to be structures
spanning and providing passage over road, waterway 2. Mathematicisation Of Aesthetics
or gorges and they were synonymous with either The theory of Building Architecture and the Aesthetics
associated with has been evolving since ancient
Even now such bridges provide passages in India, times, has been subject of discussions and numerous
popularly known as Root bridges (Fig. 1). In a sense principles and guidelines are available in manuscripts
the concept of bridge being functional and yet to be for connoisseurs. These include well known rules of
beautiful is a recent recognition of last one and half ‘Golden Section’ of Greece and various subsequent
centuries. Since then the story of bridge building attempts to produce geometric formulations in Greek
has become the yard stick for the progression in for living forms and shapes.
civilization of Nations.

Fig. 3: Golden rectangle, triangle, pentagon, spiral, etc.

Fig. 2: Represent mind of rulers at that time. The Golden ratio is a special number found by
The structures of a particular era reveal the dividing a line into two parts so that the longer part
idiosyncrasies1 (Fig. 2) of the rulers and technologists, divided by the smaller part is also equal to the whole
the degree of sophistication in technology and length divided by the longer part.” What this is saying
material sciences i.e. state of the art research and in an equation is a/b= (a+b)/a= 1.61803398874989…
(Etc.). This is also referred to be as phi, and it is an
bridge building being such a serious business, which irrational number. The ratio is represented as shown
stands as a testimony of the mental state of engineers in the Fig 3. They are also known as Golden mean,
of a particular time, to the future generation, it is Golden number, divine proportion, divine section and
imperative for us to make our posterity believe that we Golden proportion. This irrational ratio ‘ ’ (Fig 3) is
engineering fraternity possessed healthy, aesthetically a part in some or the other way in rectangle, triangle,
pleasant, creative minds. In India, as we reminisce pentagram, spiral. etc, to make them ‘divine’ section.

The Bridge and Structural Engineer Volume 45 Number 3 September 2015 43

An important sequence is introduced when we are
talking about the golden ratio. This sequence is called 2
= + 1 = 2.618, 3 = 2 + = 4.236 and so on.
the Fibonacci sequence: 0,1,1,2,3,5,8,13… Each term Thus it has a mathematical threshold of equipartition,
is the sum in the two previous terms. The more you succession and continuous proportion which can give
go to the right of the sequence the ratio of two terms rhythm to any art and physical form.
right next to each other it will get closer to the Golden
Golden ratio seem to be everywhere in the nature (Fig
Ratio.
4). This cannot only be seen in nature but it can be
seen in everything around us. The petals, leaves, pine
cones, shells and even space seem to be mysteriously
conforming to Golden section rule as such our ancient
European aestheticians tried to attribute even aesthetic
features of human being as those features conforming
to Golden section rule. These are quite obvious in
some of the classical art works (Fig 5) like An Old
man, The Vitruvian Man (The Man in Action), Mona-
Risa by Leonardo Da Vinci and Sacrament of the Last
Supper, by Salvador Dali.
Fig. 4 : Golden section seem to be all around in nature When there is a mathematical elegance in the nature
This ratio is incredible as it has certain algebraic and all around and the human psyche is used to this rhythm
geometric properties and is a transcendent number of this mathematical ratio, it is quite natural for
similar to ‘ ’ (ratio of perimeter to diameter of a humans to imbibe this very ratio in arts and artefacts
(Fig 6) for aesthetic appeal. If the manmade artefacts
each subdivision retains its original proportion and are made to follow golden section rule in some or the
is harmonically related not only to whole but to all other form, they can be incorporated in to nature with
subdivisions. For example, when a series of golden harmony.
rectangles are assembled on each other and their
outside corners are connected by a smooth curve as
depicted in Fig 3, the culmination is a golden spiral.
Luca Pacoli friend of Leonardo da Vinci called this as
‘divine proportion’ and Kepler called the ratio 1.618
as ‘one of the two jewels of geometry’ and expressed
it as a positive root of x2 = x+1.

Fig. 6: Golden section in pyramids, temple & churches

The Ahmes Papyrus of Egypt gives an account of the
building of the Great Pyramid of Giaz in 4700 B.C.
with proportions according to a “sacred ratio”. The
Greek sculptor Phidias sculpted many things including
the bands of sculpture that run above the columns of
the Parthenon. Even from the time of the Greeks, a
rectangle whose sides are in the “golden proportion”
has been known since it occurs naturally in some of
Fig. 5: Golden section in paintings of Da Vinci and Salvador the proportions of the Five Platonic. This rectangle
Dali is supposed to appear in many of the proportions of

44 Volume 45 Number 3 September 2015 The Bridge and Structural Engineer

that famous ancient Greek temple in the Acropolis in houses. The testimony of the same is found in sixty
Athens, Greece. chapters of Sanskrit manuscript Kamikagaria. This
explains the types of architecture including Testing
The Medieval builders of churches and cathedrals
and Preparation of soil and Site Selection etc.
approached the design of their buildings in much
the same way as the Greeks. They tried to connect In fact Manasara written in barbarous Sanskrit
geometry and art. Inside as well as outside, their between 5th and 7th century AD is fairly comparable to
buildings were intricate construction based on the Vitruvius of Roman architecture. The Salva Tantra and
golden section. Kama Sutra of Vatsayana enumerate 64 arts including
Taksanam (Carpentry), Vastuvidya (Architecture),
There is no evidence in the literature that golden
Dhantuvidya (Metal making), Adarajnanam (Mining)
section rules were consciously applied to the design
and Chalitaka yogah (Illusionary art).
of bridges. However, some of the elegant arch bridges
seem to be satisfying the divine proportions. It is interesting to note that the Greek and Gothic
principles considered sculpture and painting
as independent part of aesthetics while Indian
aestheticians considered the same as a part of science

music etc. 20th century Chambers Dictionary explains

the word ‘aesthetics’ as principles of taste and art: the
Fig. 7: Left : Salginatobel Bridge 4 = 6.85,
Right: Coronation bridge 2 = 2.618 word aisthetikas meaning perceptive.
It is interesting to note that the span to rise ratio
of Maillart’s famous arch bridges varied from 4.9
to 10.7 and were very close to golden section, like which was years later demonstrated by Leonardo
Stauffacher Bridge with span/rise ratio 10.7 ( 5 = da Vinci and by Le Corbusier in Modular system of
11.09), Bridge at Zuoz with span/rise ratio 10.6 ( 5 = measurement. In Hindu philosophy the form of the
11.09) Schrahbach Bridge with span/rise ratio 7.2 ( 4 purasha (human) body was made to suit the abstract
= 6.85), Hombach Bridge with span by rise ratio 7.0 idea of the square, as the supreme geometric form.
( 4 = 6.85) Salginatobel Bridge (Fig 7) with span by
rise ratio 6.92 ( 4 = 6.85), Schwamback Bridge with
span by rise ratio 6.23 ( 4 = 6.85) and Luterstalden
Bridge span/rise ratio of 4.9 ( 3 = 4.236). The
coronation bridge (Fig 7) at west Bengal over river
Teesta despite having span to rise ratio of 2.06 which
is very low for an arch bridge seem to be deriving its
aesthetic appeal by golden section rule 2 = 2.618.

Fig. 9 : Vastupurashamandala transformed into architectural

plans, superstructure depicted emotions

The basic form of the Vastupurashamandala (Fig

8) is the square and square is the important and
ideal geometric form in Hindu philosophy, which
Fig. 8 : Left : Modulur man, Right : Vastupurashamandala
represents the earth. All the necessary forms like
In India during Rig Vedic age, the architectural the triangle, hexagon, octagon and circle, etc. can be
concepts were highly developed pertaining to derived from the square. The four sides of the square
Mandirs (Temples), Mahals (Palaces & Forts) and represent the four cardinal directions. The square also

The Bridge and Structural Engineer Volume 45 Number 3 September 2015 45

symbolizes the order, the completeness of endless 3. Art Versus Science of Bridge Asthetics
life and the perfectness of life and death. Similarly,
There has been a fascinating debate for some time now
the circle represents the universe and is considered
as to whether bridge aesthetics is an art or science. It
as the perfect shape, without any beginning and end,
has been argued that Roebling’s Brooklyn, Maillart’s
Salginatobel and Christian Menn’s Sunniberg bridges
heavenly feature.
(Fig. 11) are classical art and that too ‘structural art’as
The Vastupurashamandala, having all the geometrical, coined by David Billington in bridge engineering.
astronomical and human properties was the basis of
plan for Hindu temples. The basic shape acquired These bridges when conceived and built were
by the temple plan is the outer most ring of square “revolutionary”, “ground-breaking”, and “visionary”
of the mandala forms the thickness of walls of main and indeed challenged commonly held views at that
shrine. The central 4 squares acquire the place of the point of time. The inherent characteristic of art is to
main deity and the inner ring of 12 squares form the challenge the existing ideas in meaningful ways. When
walls of the garbhagriha (shrine) and the next 16 to 28 the time tested ways are challenged in a meaning full
forms the pradkshina patha (holy circling path). These ways, the human sensibilities are emoted and lingers
simple divisions of square with many permutations much beyond wearing off instant ‘awe’ value for the
and combinations became the base for the complex experience to be termed as artistic.
structures of the temple; in the form of orthogonal and

Fig. 10 : Fibonacci Series from Pingala’s Mount Meru

stellate plans of the temple. Therefore the large squares

of mandala were divided into thousand squares thus Fig. 11 : Roebling’s Brooklyn, Maillart’s Salginotobel &
virtually forming a graph paper (Fig. 9) for the architect Menn’s Sunniberg
to facilitate him to add a unit at one side and setting
back on the other. The superstructure consisting of The aesthetic appeal of these bridges are also attributed
plinths, columns, walls, ceilings and crowns depicted to the principle called ‘Form Follows Forces’ which
emotional poses and events. is a variation of ‘Form Follows Functions’ of famous
architect Louis Henry Sullivan who was an architect
It is quite obvious that ancient aestheticians considered of skyscrapers. Sullivan’s idea of ‘Form Follows
Functions’ was from architectural point of view
of aesthetics but not necessarily the structures like
where the utilities having identical functions should
temples. As a historical background, if one goes to
be consistent in tall multistory buildings. In case of
bridges ‘Form Follows Forces’ means the structural
poetic meters of long and short syllables, Pingala ( BC
dimensioning of members just to cater for internal
200) presents the Mount Meru which is also known as
the Pascal’s triangle (Fig. 10, left side). The shallow
or the form itself. Here we are dealing with statics,
diagonals of the Mount Meru sum to the Fibonacci
series, whose limiting ratio is the golden mean (Fig
10, right side). Thus there is historical evidence that
golden section rules were in built in music and other Science is a method of doing things. It “is the organized,
art of India, much before the Fibonacci series were systematic enterprise that gathers knowledge about
recognised. the world and condenses the knowledge into testable

46 Volume 45 Number 3 September 2015 The Bridge and Structural Engineer

laws and principles”
considering and representing facts. It is very objective
results, preferably by independent investigators. being completely detached and impartial.
The second is a reporting of research as simply and
Gold’s representation of the ‘four hats of creation’
(redrawn in Fig 12) is very useful in understanding
subject to universally accepted and unambiguous
the bridge aesthetics vis-à-vis science and art. The
upper half represents the ‘search for truth’ whereas
stimulates new learning and new knowledge. And
lower half represents ‘problem solving’. Left half
represents the strength of drawing skills, sketching
connected and proved consilient with one another.
and imagining visual world on the basis of strong
Thus, there seem to be merit in both the arguments that observation of nature. The right half represents the
bridge aesthetics is an art as well as science. While strength in mathematical ability. As we can see in the
Fig12, Salginatobel Bridge follows the principle of
seem to be some commonalities in both the activities
such as: economy of the bridge. The design and construction of
Both are creative process and have the element of
synthetic thinking and generation of ideas in the process whether bad or good which is a truth (Reality).
process. But the other truth is that the design and engineering,

‘Visual thinking’ & ‘visualizing imagined worlds’ alone can’t render the artistic elegance to the bridge.
are the essential part of art as well as science. There has to some qualitative and subjective attributes
Both share sensitivity to aesthetics, although their to ‘take the science to the level art’.
criteria for ‘beauty’ may be quite different.
Artists as well as scientists are generally averse
to social interactions; they prefer to toil in their
laboratories or studios.
The labour and inspiration of science as well as
art depends largely on nature and natural world.

Leonardo da Vinci, Galileo, and Michelangelo who

contributed during Renaissance period were artists
as well as scientists. Throughout the Renaissance,
Fig. 12 : ‘Four hats of creation’ by r Gold (redrawn)
art and science continued to develop and interact.
In particular, the seventeenth century represented a 4. Bridge Aesthetics In India
pervasive that science and art were inseparable. Though there are enough examples of monumental
structures like Tajmahal, Temples, Palaces, Forts,
Art as well as science is a creative process culminating
Churches and Mosques in India, there is no evidence
in truth (Reality) and the process involves idea
of subjecting bridges to aesthetic treatments
generation and idea validation. In artistic settings, the
consciously in India. Prior to independence in1947,
may be hundreds of bridges were built in timber and
essential. In contrast to Science, Art (like Beauty) is
stone with a very small spans merely for the purpose
in the eye of the beholder and it is accepted that works
of crossing the rivers. Bridge building activities
of art will receive subjective interpretation.
increased seriously only after the independence,
though sporadically British built some long span
consisting of rules and procedures like mathematics, railway bridges in structural steel here and there.
theorems, and laws (For example Hooke’s law) etc. Even after the independence, if at all some long span

The Bridge and Structural Engineer Volume 45 Number 3 September 2015 47

bridges are looking elegant and aesthetically pleasing, 45.12 m span each. The bowstrings are realized
it is only because they are designed to structural by vertical mild steel hangers. The visual impact
is achieved by continuous slender tie-chord from
conforming to the principle of ‘Form Follows Forces’. abutment to abutment and also a smooth integration
of side spans with the abutments. The key to good
Few of the aesthetically appealing bridges are analysed
appearance in the bowstring girder bridge is the
below for their qualitative aesthetic attributes.
graceful overall shape, the minimum variety of
4.1 Arch bridges members, simple and attractive connection details,
judicious choice of materials such as concrete for arch
Most of the long span bridges constructed in India
to take compression, mild steel for hangers to take
up to 1950’s was of arch types, either of spandrel
tensions and masonry pier which is predominantly
type arch, semi-through arch or tied arch (bow-string
subjected to vertical force. Sometimes, it is not
girders). This is author’s strong intuition that the arch
possible to support the deck by spandrel, as in the
bridges are most sustainable bridges as majority of
case of Mand bridge constructed in 1946, which has a
the structural components in arch are axial members
main span of 50.0 m supporting the deck at around mid

Among them the Coronation Bridge, an open as ‘semi through’ or ‘half through’ arch bridge.
spandrel arch, which is constructed in 1941 across
The latest in the family is the true arch bridge in
Teesta River, Northern Bengal, deserves the special
India on NH-21 across river Beas at Ramshilla. The
recognition. The arch span of 81.71 m with the
national highway leading to the most popular hill
unusual central rise of 39.63 m was constructed by
station Manali in Himachal Pradesh passes through
suspended shuttering staying from temporary tower
congested Kullu town. The Ramshilla Bridge has a
at the location adjacent to springing point. This
span to rise ratio of 5.7 for the arch span of 100 m.
durable, elegant structure has visual appeal because
Perhaps, the aesthetic appeal of the bridge could have
of its shape and also containment in the river valley
been accentuated by avoiding the arch being skewed
with high bluff. The visual impact is accentuated by
rise to span ratio conforming to golden section rule,
bringing the span to rise ratio closer to golden section
apart from blending with the environment. The visual
rule 4 = 6.85.
success can also be attributed to the fact that the
arch element, spandrel columns and deck beams are 4.2 Integral & submersible bridges
dimensioned to the principle of Form Follow Forces.
During 1930’s to 50’s, multi framed submersible
The main columns at the springing location enhance
bridges were constructed in India and functionally
the containment effect. The entire structure has an
warranted very slender aerodynamically shaped deck
artistic elegance.
as well as pier sections. These days the similar portal

is now called integral bridges.

Fig. 13 : Coronation, Ramshilla, Mand & Alwaye

The Alwaye Bridge of 1941, which is constructed
across Periyar in kerala, has three tied arches with Fig. 14 : Top : Indrani bridge, Bottom : Krishna bridge

48 Volume 45 Number 3 September 2015 The Bridge and Structural Engineer

 and the construction type of the above superstructure
offers an overriding simplicity.
1942 is idealized with piers and deck rigidly connected
on continuous frames. Though the idealization requires
shorter spans, the horizontal clearance is larger than the
vertical clearance from aesthetic consideration.
The span-by-span construction was introduced in
India in 1970 for Krishna Bridge (Fig14) in Karnataka.
The 540 m long submersible bridge having 18 spans
of 30 m each with six spans continuity for live and
superimposed loading actions was called semi-
continuous bridge at that time. The superstructure

bearing over solid elliptical piers. The pre cast box

segments were match cast in casting yard (vertically), The height of the piers is judiciously proportioned and,
transported to the location and laid in position, glued
by epoxy mortar. The entire span being supported are accommodated within the same family of shapes.
by staging and temporary bearing was pre stressed
the bearings. There is a continuity of the outer lines
The continuity pier unit over the permanent bearing
was cast-in-situ and the pre stressing was carried out
progressively from the front end of construction. The pier cap neither belongs to super structure nor
to substructure and harmonizing of the same with the
The aerodynamic shape of the deck, continuity in the
both is a Herculean task as such avoided. Especially,
lines of deck slab, the matching of thickness of pier
where the height of the piers varies from obligatory
elements
spans to abutment, it is a challenge to choose a pier
of pier at the junction of pier top and deck slab to
shape to accommodate them into same family.
visual appeal of these submersible integral bridges.
enhanced by texturing (Fig15, right top) of piers
and superstructure. Texture is found on the surface
Since the experiment of span by span construction of all objects and is closely related to form. Texture
using precast segmental technology for Krishna Bridge
and shadings. It can be used to soften or reduce
been constructed across the country. Among them imposing scale, add visual interest, and to introduce
human scale to large objects such as piers, abutments,
and retaining walls. Distance and motion alters the
perception of texture. When viewed from a distance
aesthetic appeal.

aesthetic rendering by its geometry, superstructure 4.4 Girder slab bridges

shape including parapet & railing, pier shape, etc.
Pre cast girder slab construction in urban environment

most conducive. To make this kind of economical

construction aesthetically acceptable is a challenge in
itself.

of the roadway being serpentine in plan, the selection obligatory spans compared to adjacent approach spans

The Bridge and Structural Engineer Volume 45 Number 3 September 2015 49

and in the river bridges the navigational spans decide integrated with the longitudinal girders thereby
the span lengths for slab girder system construction. establishing continuity on top of pier being supported
by bearings. As can be seen from Fig. 17 (Top left),
the continuity established by girder integrated by
cross diaphragms renders an appearance of longer
superstructure, taller pier and lighter deck.

selection of pier shapes plays a vital role in the visual

impression. It is always a challenge to accommodate
same family of piers for varying height giving slender
appearance. The common attributes of good-looking
piers are:

Fig. 16 : Aesthetics of slab superstructure (a) The pier caps are as small as functionally
possible or otherwise eliminated.
In the design of the slab girder system, the aesthetic
goals are achieved by slenderness, continuity in (b) Shape is in harmony with girders and parapet.
lines and apparent lightness by shaping the various (c) The bearings are not hidden but made conspicuous
and deeper not wider, to distinguish between
substructure and superstructure rendering the
Mumbai is achieved by judicious proportioning of appearance of lightness and slenderness to
various structural elements. It is a myth that by hiding superstructure.
the bearings either at the location of abutments or at (d) Multiple columns piers are avoided and the
the location of piers, the visual appeal is augmented. patterns are simple and large.
As can be seen from the photograph, if the ears
were avoided on the pier cap (with an intention of look thinner.
hiding the bearings), the exposure of the bearings on (f) For the haunched/curved belly superstructure,
the slightly elevated pedestals would have made the
superstructure look lighter, thinner and continuous strength.
thereby further enhancing the aesthetics. What people
The abutment joins the bridge to the roadway in
perceive is not always what is there. Our vision is
bridges and brings the bridge from higher elevation to
susceptible to manipulation and illusion (Fig. 16,
bottom left). Designers can use illusion to improve
the height of the abutment in relation to the pier heights
the appearance of an element. For example, placing
(Fig. 16 bottom right) decides the visual impact of the
a series of vertical grooves on a column will make
overall bridge. Aesthetic appearance is enhanced by
it appear thinner. By not providing the ears to hide
provision of shorter abutments compared to the pier
the bearings, the continuous line would not have
been broken and rendered the illusion of deck being
slimmer and longer. However, the parapet and the
end girder with the overhang larger than the depth of
the end girder, causing the shadow on the girder are

Though the length of the obligatory span is more than

the approach spans, it is imperative to keep the depth
of superstructure same throughout or continue the
lines by gradually varying depth to make the structure

be eliminated by provision of the cross diaphragm Fig. 17 : Continuity of ‘Line’ & Balance

50 Volume 45 Number 3 September 2015 The Bridge and Structural Engineer

fact, though people insist for hiding the bearings
supported on abutment shaft, it doesn’t help in making
the superstructure look longer. When the abutment
shaft is distinct from return walls, by reducing the
thickness of the shaft to half of the girder depth, the
bridge looks slimmer.
Choosing a color scheme and landscaping for bridges

The judicious choice of color scheme to merge with

the surroundings can be seen in recently constructed Fig. 18 : Cast in situ balanced cantilever construction
New Mattancherry Bridge (Fig 16, top right) at Barak Bridge at Silchar (Fig: 18, top left), built in 1961
Cochin. It can be observed that the colors are used
to distinguish the structural elements and the variety in-situ segmental construction method in India. The
in colors is minimal. Normally the brighter colors foundation meant for originally envisaged suspension
like red, blue, green and orange are preferred to bridge was utilized. The bridge has a clear span of
lighter colors. Sometimes the colors can be picked 122.0 m with a mid-span pendulum hinge. The twin
to create contrast against background to make the piers, monolithic with the spans are slender. The
structure very conspicuous. The colors are never slenderness of the main piers and the high stiffness
of the approach piers accentuate the functionality
used to obscure the functionality of an element but
can be used to emphasize the shape. Colours are
caps for the main spans brings harmony between
perceived differently at different times of the day and superstructure and substructure while the provision
at different times of the year because of the changes of crest vertical curve renders slightly an appearance
in light conditions created by changes in sun position of arch. There after many bridges like Zuari at Goa,
and atmospheric conditions Bassien Creek Bridge, Gourang Setu, Balason Bridge
at Darjeeling and so many others were constructed
Another important feature of the Mattancherry Bridge
with this principle. The 290 m long Balson Bridge
is the landscaping of the approach protection. The
at Darjeeling (Fig. 18, bottom left) is one such
elegance of the bridge can be further enhanced by bridge with the continuous system having central
plantation of greeneries on the bank protection. span of 130 m and two shore spans. Situated among
Visual balance (Fig. 17 top right & bottom) which is the scenic surrounding, Balason is one of the most
aesthetically beautiful bridges. The elegance of the
the perceived equilibrium of design elements around
bridge is enhanced by the piers, which are unusually
an axis or focal point is very important for aesthetic
slender, perfectly blends with the ambience.
rendering. Rather than a physical balance, it may refer
to equilibrium of abstract elements of design, such as
masses, visual weights or texture.

4.5 Cantilever construction

For rivers and strait crossings, also to bridge the
gaps of the ravines and gorges and creeks, long span
bridges are called for to overcome the foundation
problems and to provide navigational clearance,
etc. The picturesque surrounding of these locations
naturally provides an excellent back ground for long Fig. 19: Top : Free cantilever cast in situ,
span bridges. Bottom : Precast segmental

The Bridge and Structural Engineer Volume 45 Number 3 September 2015 51

 mid span is long enough with the parabolic curve
constructed by cantilever Construction method, akin to the moment diagram.
Reduction in depth from root towards midspan is
21.0 m anchor spans progressed into rock mass and
not formed with straight line as the sharp break
counterweighted by roller bearing at the top against
makes the haunch look short. Also when the
the rock mass. The Jadukata Bridge (Fig. 19, top left)
bearings are provided on top of the pier cap, the
with the central span of 140.0 m, the longest span in
same is placed on pedestals and higher, making
the country when conceived and constructed, was
the deck look lighter.
Near the abutments, the ground merges with the
the conception of arch to take the thrust nor the roadway and the height of the abutment is much
provision of piers in between. The central span being lesser than that of piers.
constructed by cantilever in-situ segmental method
At the mid length of the bridge crest vertical
has adjoining spans of 36.5 m progressed into the
curve is provided to give an appearance of arch.
inside the adjoining spans. 4.6 Cable supported bridges
After having gained experience in cast-in-situ Whenever the signature bridges are envisaged, it is
segmental cantilever construction for long span quite common to think of suspension or cable stay
bridges, the next evolutionary step was to introduce bridges. The Akkar Bridge (Fig: 20, top left) over
pre cast segmental cantilever construction for the
bridges with many spans. The Buxar Bridge (Fig. stayed bridge constructed in India. The continuous
deck of 158.0 m on either side of 57.5 m tall pylon
bridge in India to adopt this technology. This bridge is suspended freely from the pylon which has two
had 10 spans of 101 m and was followed by Narmada concrete box legs on either side of 7.5 m wide
Bridge at Zadeshwar with 13 spans of 96.0 m. 5575 carriageway being connected at top by cross tie
m long Ganga Bridge at Patna (Fig. 19, bottom left) between cable anchor heads.
with 45 numbers of 121.05 m span made up of 3.0 m
segments match cast by short line method at casting
yard is the longest river bridge constructed in the
country using pre cast segmental construction method.
Some aspects of transparency of these cantilever
bridges reveal some common aesthetic attributes.
The span length to vertical clearance from low

yielding the maximum frame area under the span

to view the scenic landscape or view through the
bridge.
Fig. 20 : Cable stay bridges of India
The shape of the structural elements perfectly
Each and every structural element of the cable stayed
functionality, perhaps following the principle of bridges such as cables, deck system, pylon and
‘Form Follows Forces’. merging of the deck with abutment is lighter, slender,
and simple and expresses the functionality and force
The lines are continuous without break and level in a pronounced manner, which are obviously
either the pier caps are eliminated or just enough the reasons of aesthetic appeal epitomized for this
to accommodate bearings, harmonizing the family of bridges. Therefore it is averred that ‘there
superstructure with substructure. must be an inherent beauty in cable stayed bridges
The depth of the girder at the root is generally
larger and the gradual reduction in depth towards cable stay bridges ugly’.

52 Volume 45 Number 3 September 2015 The Bridge and Structural Engineer

 to ship or a plane and once again testimony of
aestheticians’ quest for incorporating the structures in
to nature.
The cable stay bridges by its inherent nature follows
the principles of ‘Form Follows Forces’ but also
provides opportunity to apply the principles of golden
section rules involving golden rectangle, triangle,
spiral and phi.
The inventor of extradosed bridge, a variation of cable
supported bridge, Christian Menn has demonstrated
that the bridge design could be a structural art through
his breath taking Sunniberg Bridge. Even in India
many extradosed bridges are constructed in the recent
Fig. 21 : Bridges in motion
852.96 m long Second Hoogly Bridge or Vidyasagar
Setu (Fig: 20, top right) at Kolkata with cable stay
spans of 457.20 m, supported on two identical pylons
with adjacent stayed spans of 183.0 m provides a clear
navigational height of 34.0 m under HFL conditions.
In fact, when it was conceived it was the longest span
cable Stay Bridge in the world. Analogous to any cable
Fig. 23 : Extradosed principle opened up numerous aesthetic
supported bridges, the identical pylons, minimum
options
variety in shape and size of structural elements etc
are the hallmarks of its aesthetic appeal. Logically it past like, Indraprastha, Moolchand and Siddapura
is inconceivable to imagine a cable-supported bridge bridges to name a few. In Indian extradosed bridges
not to be elegant. a special attention to aesthetics are found to be
wanting (Fig. 22). This variation of cable supported
The recent Bandra Worli cable stay bridge in Mumbai bridges provides numerous opportunities (Fig. 23)
designed by S Srinivasan (Fig. 20, bottom left) is a gift to the designer to enhance the aesthetics of bridges
to the city where the main pylons symbolically greet where designer can adjust the height of pylons to suit
the guests in a traditional Indian pose “Namaste”. golden section rules, can shape & incline the pylons
Srinivasan has not only enhanced the aesthetic appeal to express the local symbolisms, can sway outwards
of this bridge with his trademark texturing but also to give an impression of welcoming arms, etc.
harmonised approach span deck with cable stay
span decks by adopting the same cross section. The 5. Conclusions
Signature Bridge at Delhi (Fig. 20, bottom right)
which is under construction created by Schlaich (Jorg The above illustrations explain numerous common
& Mike) is one of its kind in the world and a bridge in characteristics for bridges to be good looking, such
motion. Santiago Calatrava, an architect cum sculptor as:
cum engineer is a master of structures in motion (Fig.
hence bold expressions in concrete.
2. Invariably, the aesthetics are complimented by
creative and innovative process.
3. The structural elements are simpler and less in
variety, viz for the same function, elements has
same size and shape.
4. The elements are made to look slender, longer,
Fig. 22 : Extradosed bridges of India

The Bridge and Structural Engineer Volume 45 Number 3 September 2015 53

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5. The lines are continuous without any abrupt & forts) and Masjids (Mosques) in India, Churches,
jumps. Cathedrals and Castles elsewhere not only give
insights to the mental makeup of the rulers but also
6. The structural elements performing different
help us in understanding the degree of religiosity and
functions are emphasized in its functionality
civilization of the century.
without hiding, for example, hiding bearings
make the superstructure look thicker. Inarguably no engineer predilects his creation to be
ugly. Still, in the recent past we witness accelerated
growth of fast conceived, hastily churned out in
masses, so called fast tracked eyesores particularly in
‘Form Follows Forces’ .
Indian context all around. Do we need our posterity to
8. There is a certain pattern or a relationship remember us by these artifacts?
between the following elements or as a whole
which may be accidentally following golden References
section rules incorporating the bridge in to 1. Fritz Leonhardt, Bridges-Aesthetics and Design,
nature and surroundings : Publication DVA, 1982.
a. Height of the pier to span length. 2. Golden Section in Art and Architecture, (http://
www.camosun.bc.ca/~jbritton/goldslide/).
b. Width of the pier to span length.
3. J.H. Cartwright, D.L. Gonzales, O. Pero, and
c. Overhang of the slab to girder depth D. Stanzial, “Aesthetics, dynamics, and musical
scales: a golden connection.” J. New Music
d. Height of the abutments to pier height
Research 31, 51-68, 2002.
e. Depth of the girder to span length 4. Kak, S. “Space and Cosmology in Hindu
f. Height of the pylon above formation level Temple.” Vaastu Kaushal: International
to span length in case of cable supported Symposium on Science and Technology
bridges. in Ancient Indian Monuments. New Delhi,
November 16-17, 2002.http://www.ece.lsu.edu/
g. Height of the crown from foundation top kak/Time 2.pdf.
level to span length in case of arch bridges. 5. Michell, G. 1988. The Hindu Temple: An
9. A slight mid-length vertical curve giving an Introduction to its Meaning and Forms. Chicago
appearance of arch, which is always pleasant. and London: The University of Chicago Press.
6. Sullivan, Louis. Kindergarten Chats. New York:
Bridge Aesthetics is neither the external
Wittenborn, Schultz, Inc., 1947
ornamentations, embellishments nor the building
7. Billington, David P. The Tower and the Bridge.
aesthetics and creativity have to compliment each other New York: Basic Books, 1983.
in the art and science of Bridge engineering. Though 8. R. Gold. The Plenitude: Creativity, Innovation,
and Making Stuff. MIT Press, Cambridge,
aesthetics as the adage goes ‘Beauty lies in beholders Mass., 2007.
eyes’, the beholders can be saved from witnessing 9. Andrew J Tapping, The Salginatobel bridge,
mediocrities by observing certain minimum criteria Bridge Engineering 2 Conference 2007 04 May
as laid down in the illustrations above. 2007, University of Bath, Bath, UK
The bridges of an era reveal the idiosyncrasies of 10. Gottemoeller, Frederick. Bridgescape: The Art
the time in terms of the degree of sophistication in of Designing Bridges. New York: John Wiley &
technology, material sciences, state of the art research Sons, 1998.
11. V N Heggade “Bridge aesthetics-Some issues”,
In fact, the bridge building reveals the state of the 3rd
nation’s progress and civilization of a particular Globally & Build Locally, May 29-June 02,
era. The great Mandirs (Temples), Mahals (Palaces 2010, Washington. D.C.

54 Volume 45 Number 3 September 2015 The Bridge and Structural Engineer