Indian Bahá'í Temple
Background and
Architecture
Extracts from Interviews with the Architect
The Jewel in the Lotus
Architectural blossoming of the Lotus
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Architectural blossoming
of the Lotus
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 The temples of the Bahá'í Faith are well known for their
architectural splendor, and the Temple constructed in Delhi is a
continuation of this rich tradition. Before undertaking the
design of the temple, the architect, Mr. Fariborz Sahba, had
travelled extensively in India to study the architecture of this
land and was impressed by the design of the beautiful temples,
as well as by the art and religious symbols wherein the lotus
invariably played an important role. He was influenced by this
experience, and in an attempt to bring out the concept of
purity, simplicity and freshness of the Bahá’í Faith, he
conceived the Temple in Delhi in the form of a lotus. The temple
gives the impression of a half-open lotus flower, afloat,
surrounded by its leaves. Each component of the temple is
repeated nine times. Flint & Neill Partnership of London were
the consultants and the ECC Construction Group of Larsen &
Toubro Limited were the contractors responsible for constructing
the Temple.
The temple complex, as seen from the layout, consists of the
main house of worship; the ancillary block which houses the
reception centre, the library and the administrative building;
and the restrooms block. The temple proper comprises a basement
to accommodate the electrical and plumbing components, and a
lotus-shaped superstructure to house the assembly area.
All around the lotus are walkways with beautiful curved
balustrades, bridges and stairs, which surround the nine pools
representing the floating leaves of the lotus. Apart from
serving an obvious aesthetic function, the pools also help
ventilate the building.
 The lotus, as seen from outside, has three sets of leaves or
petals, all of which are made out of thin concrete shells. The
outermost set of nine petals, called the 'entrance leaves', open
outwards and form the nine entrances all around the outer
annular hall. The next set of nine petals, called the 'outer
leaves', point inwards. The entrance and outer leaves together
cover the outer hall. The third set of nine petals, called the
'inner leaves', appear to be partly closed. Only the tips open
out, somewhat like a partly opened bud. This portion, which
rises above the rest, forms the main structure housing the
central hall. Near the top where the leaves separate out, nine
radial beams provide the necessary lateral support. Since the
lotus is open at the top, a glass and steel roof at the level of
the radial beams provides protection from rain and facilitates
the entry of natural light into the auditorium.
Below the entrance leaves and outer leaves, nine massive arches
rise in a ring. A row of steps through each arch lead into the
main hall (see Fig. 1).
The inner leaves enclose the interior dome in a canopy made of
crisscrossing ribs and shells of intricate pattern. When viewed
from inside, each layer of ribs and shells disappears as it
rises, behind the next, lower layer (see section on p. 29). Some
of the ribs converge radially and meet at a central hub. The
radial beams emanating from the inner leaves described earlier
meet at the centre of the building and rest on this hub. A
neoprene pad is provided between the radial beams and the top of
the interior dome to allow lateral movement caused by the
effects of temperature changes and wind.
Geometry
 The beautiful concept of the lotus, as conceived by the
architect, had to be converted into definable geometrical shapes
such as spheres, cylinders, toroids and cones. These shapes were
translated into equations, which were then used as a basis for
structural analysis and engineering drawings. The resultant
geometry was so complex that it took the designers over two and
a half years to complete the detailed drawings of the temple. An
attempt is made below to describe this complex geometry in
simple terms (see Fig. 2).
Entrance leaves and outer leaves.
The shell surfaces on both sides of the ridge of the entrance
and outer leaves are formed out of spheres of different radii,
with their centres located at different points inside the
building. There is one set of spheres for the entrance leaves,
some of which define the inner surfaces, and others which define
the outer surfaces of the shells. The diameters of the spheres
have been fixed to satisfy the structural consideration of
varying shell thickness. Similarly, for the outer leaves,
another set of spheres defines the inner and outer surfaces of
the shells. However, for the outer leaves, the shell is
uniformly 133 mm thick towards the bottom, and increases to 255
mm up to the tip, beyond the glazing line.
The entrance leaf is 18.2m wide at the entrance and rises 7.8m
above the podium level. The outer leaf is 15.4m wide and rises
up to 22.5m above the podium.
The inner leaves.
Each corrugation of the inner leaf, comprising a cusp (ridge)
and a re-entrant (valley), is made up of two toroidal surfaces.
A toroid is generated when a circle of a certain radius, 'r', is
rotated around the centre of a circle of much larger radius,
'R'. A cycle tube is a typical toroid. The shaded portion of the
toroid is a part of the inner leaf shell.
The inner leaves rise to an elevation of 34.3m above the inner
podium. At the lowest level each shell has a maximum width of
14m. It is uniformly 200mm thick.
The arch.
All around the central hall are nine splendid arches placed at
angular intervals of 40 degrees. The shape of these arches is
formed by a number of plane, conical and cylindrical surfaces.
The intersection of these surfaces provides interesting contours
and greatly enhances the beauty of the arches. The nine arches
bear almost the entire load of the superstructure (see Fig. 2
and 4).
The interior dome.
Three ribs spring from the crown of each arch. While the central
one (the dome rib) rises radially towards the central hub, the
other two (the base ribs) move away from the central rib and
intersect with similar base ribs of adjacent arches, thus
forming an intricate pattern. Other radial ribs rise from each
of these intersections and all meet at the centre of the dome.
Up to a certain height, the space between the ribs is covered by
two layers of 6Omm-thick shells. The intricate pattern of the
interior dome is illustrated in section on page 29.
Setting out
 The setting out of the surface geometry posed a difficult task.
Unlike conventional structures for which the elements are
defined by dimensions and levels, here the shape, size,
thickness, and other details were indicated in the drawings only
by levels, radii, and equations. These parameters, therefore,
had to be converted into a set of dimensions in terms of length,
breadth, height, and thickness, easily understood by a site
engineer or a carpentry foreman. To achieve this, a system of
coordinates along x, y and z axes for every 40 degrees. segment
of the temple was worked out with the help of a computer. The
problem was then further simplified by working out from these
co-ordinates levels and distances which a carpenter or a
reinforcement fitter could easily comprehend and then arrive at
the surfaces and boundaries. Eighteen reference stations were
established outside the building for setting out the arches,
entrance, outer and inner leaves (see Fig. 3).
First, 18 radial lines were established from the centre of the
building (see Fig. 4). Along these lines, using inclined and
vertical distances, end points A and B for surface (1) were
established. By using a set of curved templates, each of varying
curvature, surface (1) between these lines was developed. From
this surface the other surfaces of the arch were set out by
using stepped templates with respect to surface (1).
The stations shown in Fig. 3 were used to set out the cusp,
re-entrance and edge lines for the entrance, outer and inner
leaves. For example, to arrive at curve AB, point A with
coordinates XA, YA, ZA was defined with respect to 0. AB was
then established by a second theodolite and the curve AB
determined by a stepped template. Accurately made curved
templates of required radii were then used to develop the
surface between these boundaries (see Fig. 5).
Sequences of construction
 The basement and the inner podium were constructed first.
Thereafter, for casting the arches and shells, the structure was
divided into convenient parts, taking into consideration that
when deshuttered, the portion of the shells cast would be
self-supporting until the remaining shells were completed. The
structure was divided as follows:
Arch.
All 9 arches were cast one after the other in two lifts until
the circle was completed. The deshuttering of the soffit of each
arch was taken up after the adjacent arches had attained
specified strength (see Fig. 8).
Inner leaf, radial beams and central hub.
After the completion of all the arches, the structural steel
staging for the inner leaf was erected. Three shells, 120 deg.
apart, were taken up at a time and cast in two lifts, one after
the other, up to the radial beam level, ensuring always that the
difference in height between the shells cast was not more than
one lift (see Fig. 6). The process was repeated until all 9
segments were cast. Casting of the central hub was taken up as
an independent activity, and after all the shells were cast,
they were connected to the hub by casting the radial beams.
After sufficient curing, the inner leaf along with the radial
beams were dewedged, leaving the central hub supported. The
remaining portion of the inner leaf was then taken up (see Fig.
7).
Interior dome.
After de-wedging of inner leaf, the steel staging was modified
and two folds of shells of the interior dome taken up one after
another. For each fold, three shells, 120 deg. apart, were taken
up at a time and cast one after another. For each shell the
boundary ribs were taken up first and then the shell cast in one
single lift. The process was repeated until all the shells were
completed.
Entrance and outer leaves.
The construction of the entrance and outer leaves was taken up
as a parallel activity with the casting of the inner leaves and
interior dome. Two entrance leaves and one intermediate outer
leaf were taken up First. Thereafter, the outer and entrance
leaves were cast alternately, the outer leaf first and then the
adjacent entrance leaves. Deshuttering was started with a pair
of outer leaves and followed by the intermediate entrance leaf.
In this manner the remaining leaves were deshuttered as and when
the concrete attained strength and the leaves adjacent to the
shell to be deshuttered were cast.
Staging and formwork
 Deflection was an important consideration in the design of the
formwork. The maximum deflection was limited to 3mm over a
distance of 1m (including errors in fabrication and erection).
The following aspects were considered in arriving at
the general arrangement of the staging supporting the
inner leaf and interior dome formwork:
a. The concreting of the shells should be taken up 3 at a time,
120 deg. apart, so that the lateral loads on the staging
supporting the formwork were reduced as far as possible.
b. Construction joints were to be avoided as far as possible so
that the exposed concrete surface did not show any lines other
than the architectural pattern. For the inner leaf, construction
joints were to be located above 24.8m level so that they did not
show from the floor level. All other shells were to be cast in a
single continuous pour.
c. The staging should support the radial and base ribs without
interfering with the structural steel members. After
deshuttering of inner leaf, the structure should be able to
support the formwork of the inner layers of shells of the
interior dome with minimum modification.
From the above considerations, a space frame consisting of 9
radial cusp frames and 9 re-entrant frames, with circumferential
and diagonal members closely following the profile of ribs and
shells, was considered most suitable (see Fig. 7).
Various alternatives were considered for the steel staging.
Standard pipe scaffolding was found to be unsuitable,
considering that the slippage of members at joints would be
uncertain and it would be difficult to compute and control the
deflection, particularly due to lateral loads. Structural steel
framework with bolted joints was found to be unsatisfactory,
considering that a very high degree of accuracy in fabrication
and erection of structural work would be required to match the
bolt holes at junctions of members meeting at different
inclinations in all three planes. Structural steel framework
with welded joints was considered to be most suitable because
deflections due to slippage of joints would be avoided and
fabrication and erection would be comparatively easier.
The inner surfaces of all the shells have a uniform,
bush-hammered, exposed concrete surface with architectural
patterns. For the inner leaves, these patterns were formed out
of radial and vertical planes intersecting the surface of the
torus. For the outer and entrance leaves, and the interior dome,
the patterns were formed out of longitudes and latitudes of
spheres. The formwork was designed in a manner that timber
joists support the panels instead of the regular pattern of the
structural steel supporting members of the space frame (see Fig.
8).
Full-scale mockups of the bottom surface of each of the shells
were first made at ground level and the architectural patterns
marked on this surface. The frame of each form panel was
fabricated according to calculated dimensions and cross-checked
with measurements from the mockup. The formwork pattern is seen
in the photograph on page 70.
The inner formwork for every petal was fully fixed from bottom
to top and aligned accurately. After the formwork was approved,
the sheathing joints where sealed with putty made out of epoxy
resin and plaster of Paris, and a protective coating was applied
over the plywood surface. In the case of the interior dome
shells, the plywood sheathing was lined by fiber-reinforced
plastic sheets and the joints sealed with epoxy resin. After
this, the location of each reinforcement bar was marked on the
formwork along latitudes and longitudes and the bars placed over
the markings. To avoid impressions of cold joints on the inner
surface, the casting of petals of the inner leaf was carried out
in three lifts, some of them 14m high. To facilitate placement
of concrete and simultaneous compaction in each pour, the outer
formwork was placed one row of panels at a time, and as the
level of concrete rose, the next row of panels was fixed. These
panels, therefore, had to be fixed in position and aligned
accurately in the shortest possible time.
Through selected points matching with the architectural pattern,
pipe supports were taken from the inner leaf staging. These
pipes supported a structural steel grid closely following the
profile of the outer surface of the shells. The grid supported
the outer formwork against the concrete pressure and also
accommodated the working platforms at all levels. Through-ties
connecting the inner and outer forms were provided at selected
points so as to reduce the load on the steel staging and limit
the deflection of formwork.
The longitudinal support members of the backform had accurately
aligned shaped members, such that when the backform panels were
placed in position and wedged, the outer surface of the shell
was attained without further alignment (see Fig. 9). To ensure
that the panels fitted exactly between the shaped members and
there was no delay, the fixing of the panels for the entire
shell was carried out in advance.
Loading
 The following loads were considered for the design of the
formwork:
I. Dead load of formwork - 750 N/m2 of surface area.
II. Self-weight of structural steel members.
III. Live load 2000 N/m2 of plan area.
IV. The greater of dead load of concrete (or) liquid pressure at
any point corresponding to the rate of placement 0.45 m/hr and
minimum temperature of 10 deg. C (during winter). Concrete
pressure was calculated as per ACI publication - SP.4. Liquid
pressure p = 7.2 + ([785R]/[Tc + 17.8]) P = Lateral liquid
pressure - KN/m2 R = Rate of placement — m/hr Tc= Temperature of
concrete in the forms deg. C
V. Basic wind pressure = 1000 N/m2
For the inner leaf, various combinations of the above loads were
considered for the following conditions (see Fig. 4):
Stage I Concrete from top of arch to +24.8m level Stage II
Concrete from +24.8m to +38m level Stage III Concrete from
+38.8m to the top
The combination of loads considered were:
1. Self-weight of space frame (symmetrical)
2. Dead load of shutter
3. Live load + dead load of concrete Stage I (unsymmetrical)
4. Live load + dead load of concrete Stage I (symmetrical)
5. Live load + dead load of concrete Stage II (unsymmetrical)
6. Live load + dead load of concrete Stage II (symmetrical)
7. Live load + dead load of concrete Stage III (unsymmetrical)
8. Live load + dead load of concrete Stage III (symmetrical)
9. Wind load for full height (unsymmetrical)
Based on the above loads, a computer analysis for all possible
combinations was carried out using SAP IV program. One cusp
frame and one re-entrant frame along with inter-connecting
bracings were considered as a unit.
A computer model indicating the loads due to one of the
combinations of loading for Stage II is shown in Fig. 10.
Similar loading conditions were considered for the entrance and
outer leaves as also the shells of the interior dome, the only
difference being that all the shells were cast in a single pour.
Reinforcement
The reinforcement used in the white concrete shells as well as
the binding wires was entirely galvanized so as to prevent the
long-term effect of rusting of reinforcement on the white
concrete. Since galvanized reinforcement for concrete is seldom
used in this country, several tests were carried out to ensure
that the mechanical properties of reinforcement did not become
adversely affected due to galvanizing. Sandblasting was carried
out to reduce pickling time with a view to avoiding hydrogen
embrittlement. The bottom formwork for one shell for each of the
leaves was first erected and aligned. The edge lines and
surfaces of this formwork were then used as a mockup to decide
the length and shape of each bar in the shell. To avoid the
impression of cover blocks on the exposed surface of the shells,
the inner layer of reinforcement was held in position by special
steel spacers supported from the outer formwork.
Concrete
 All the ribs and shells up to radial beam level are in white
concrete. To avoid crazing and shrinkage cracks, a mix of M 30
grade white concrete was designed considering that the cement
content should be below 500 kg/m3 and the quantity of water
reduced to a minimum.
Tests carried out on Indian cement revealed that the strength
and other properties varied considerably and the colour did not
meet the architectural requirement. Trial mixes also showed a
higher cement requirement of 430-450 kg/m3. The entire quantity
of white cement was therefore imported from Korea. With the
imported cement, it was possible to produce concrete having 28
days cube strength of 55-60 N/mm2 with a cement content of 380
to 400 Kg/m3. A mix of 1:1.44:3.36 and w/c ratio of .42 was
adopted. To achieve a high workability, slump 1-120 mm, super
plasticiser, .5 to .75% by weight of cement was used.
Specially graded dolomite aggregates were procured from the
Alwar mines near Delhi and white silica sand from Jaipur. The
maximum temperature of concrete at the time of placing was
limited to 30 deg. C. During the summer months, when the ambient
temperature was as high as 45 deg. C, the temperature of the
concrete was controlled by adding a measured quantity of ice and
by the precooling of aggregates in air-cooled aggregate storage
bins. To avoid cold joints due to stoppage of work during heavy
rains, as also to protect rain water entering the forms, the
entire concreting area was covered by tarpaulins.
After removal of the outer forms, the surface of the concrete
was covered with hessian and cured for 28 days by keeping it wet
continuously by a sprinkler arrangement fixed at the top of the
shells.
Trials and mockups
The shells of the interior dome were initially 50mm thick and
proposed to be cast by in-situ guniting. Full-scale mockups were
used to study the problems of working space and accessibility,
and it was felt that due to limited space available between the
shells, the working conditions for guniting operations would be
difficult. As an alternative, the shells were therefore proposed
to be constructed in in-situ concrete using formwork on both
faces. Considering that each shell had to be cast in a single
pour, the fixing of formwork and reinforcement, as also the
placement and compaction of concrete between two faces of
formwork only 60 mm apart, posed serious problems. Not only was
the formwork difficult to align so as to accurately produce the
complex, doubly curved surface and the intersections, but also
the closeness of the petals, one fold behind the next, caused
serious problems of work space for fixing formwork,
reinforcement and concreting.
Quality assurance
Based on the sequence of construction envisaged, the assumptions
made in the design of the formwork, the procedures developed
from mockups, and the tests carried out on materials, detailed
method statements and criteria of acceptance were established.
Checking of workmanship was done at each stage to produce the
required quality and accuracy and also to ensure that there was
no deviation from the conditions of loading assumed in the
design of the formwork. A full-fledged concrete laboratory
carried out mix designs for different grades of concrete and
exercised strict control on the quality of concrete.
Marble cladding
 The outer surface of the shells, as also the inner surface of
the arches, are cladded with white marble panels fixed to the
concrete surface with specially designed stainless steel
brackets and anchors. 10,000 sq.m. of marble was quarried from
the Mount Pentilekon mines of Greece and thereafter sent to
Italy, where each panel was cut to the required size and shape
to suit the geometry and architectural pattern before
transporting them to the site in Delhi.
After waterproofing of the top surface of each shell, timber
templates of the same size as the marble panels were used to
define the location of the bottom-most rows of marble panels
first. The geometry of the cusp re-entrant and edge lines was
then accurately checked with respect to these panels, and the
marble pieces were fixed in position from bottom towards top and
cusp towards reentrants and edges. Edge holes were drilled at
ground level for each marble panel before the panels were placed
in position. Holes were drilled in the concrete to accommodate
the anchor fasteners of the stainless steel brackets to suit the
holes in the marble, after each panel was aligned. After fixing
of the brackets, the area around the bracket hole was sealed
with a special waterproofing compound (see Fig. 11).
The alignment of the panels was adjusted at each layer so that
the surface geometry and pattern lines were maintained. The
pieces near edge, re-entrant and cusp lines were cut to suit the
boundary lines. Gaps 8 to 10 mm wide at the joints were filled
with moulded rubber cordon, and the top of the joints, as also
the holes in the marble, sealed with silicon sealant. The entire
marble surface was, lastly, washed with a solution of 30%
muriartic acid mixed in water, to remove dirt and stains.
A specially designed structural steel framework was provided to
accommodate access and working platforms. The platforms were
free from the surface of the shells so that the marble fixing
could be carried out without any hindrance from the supports of
the staging.
It may be interesting to note that all the marble work was
carried out by carpenters who learned the skill of marble fixing
within a few weeks, and were able to complete the work, to the
required accuracy, two months ahead of the scheduled completion
time.
Project management
The complexity of the structure, and the very high standards of
workmanship expected to be achieved, demanded a dynamic
construction management with a high degree of innovativeness,
team spirit and quality consciousness on the part of staff and
workmen. Anticipating problems in advance and solving them
through trials and mockups was an essential part of site
planning. Further, great emphasis was laid on the completion of
the project within the stipulated time and cost. Resources were
planned and physical progress monitored through constant review
of PERT/CPM networks.by S. Naharoy |
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