With the steady rise in the Indian economy, the construction industry has become the second largest industry which contributes to the country's growth. This growth magnified demands for quick, clean and hassle free construction technologies and has thus laid 'concrete' foundations for the precast technology in India. An example of this trend is the Infosys multi level car park in Pune (photo 1). The challenging project is constructed fully in concrete, without any other materials, with the combination of prefabricated elements and in-situ concrete.
90
thema
Infosys multi
level car park
1
Challenging Indian project in prefabricated and in-situ concrete
Precast India IPL built the Multi-Level Car Park for their client,
Infosys Ltd, in their Pune campus. This eye-catching, half a
million square feet multi-level car park was used for the cover
page of fib Bulletin 78 and was also named as 'The Outstanding
Concrete Structure of India-2016' by Indian Concrete Institute
(ICI). Special awards were also won in architectural, structural
and precast construction categories.
In total there were 3500 elements in the building of the Infosys
multi level car park, consisting of: 16 m span precast TT slabs,
15 m precast concrete columns, and 1300 façade elements each
around 7 m long and weighing 2.5 tons, triangular in profile,
fixed in around 160 days on-site, with a self-designed and
electronically managed factory and construction site coordina-
tion, culminating in the installation of all elements within an
erection tolerance limit of +/- 10 mm. With the steady rise in the Indian economy, the construction
industry has become the second largest industry which contributes
to the country's growth. This growth magnified demands for
quick, clean and hassle free construction technologies and has
thus laid 'concrete' foundations for the precast technology in
India. An example of this trend is the Infosys multi level car park
in Pune (photo 1). The challenging project is constructed fully in
concrete, without any other materials, with the combination of
prefabricated elements and in-situ concrete.
thema
Infosys multi level car park 3 2017
91
LIFT-1
LIFT-2
LIFT-3LIFT-4
LIFT-5
LIFT-6 The precast concrete elements in the building speak volumes
about the innovations and the cutting edge technologies that
were used for the construction of this magnificent structure.
Concrete was chosen over glass, which resulted in excellent
natural lighting and ventilation factors, minimizing future
maintenance costs, and enhancing safety.
International architectural design competition
To meet the client's requirements, Precast India conducted an
international design competition for the façade. From a
number of designs, the entry from Arch Domingo Seminario
was selected. The architecture of this structure is a perfect
example of how uber modern structures can be designed to
blend with the basic architectural concept evolved from and
resembling the warmth of woven wool, with a virtue of
unharmed air circulation along, with sufficient mild sun light
entrainment in all the area.
The parking structure comprises of a basement and ten floors
with a parking capacity of around 1300 cars. In addition to
precast concrete columns, beams, double tee slabs, hollow core
slabs, staircases, and spandrels, the uniqueness of the building
lies in its 1300 odd, 100 mm thick precast concrete façade
elements (photo 4) [5], all of which were produced and trans-
ported from Precast India's plant (photo 5) 45 km away from
the site.
This is a unique structure of its kind in India, where, instead of
glass or aluminum composite panels, structural concrete
prefabricated elements are used for the façade.
Structural design
The structure lies in seismic zone 3 [1] and was designed and
analyzed by a team of experienced structural designers, led by
prof. Sypros Tsoukantas and mr. Tryfon Topintzis. The struc-
tural design of the precast elements [4] was complex as it
involved intricate connections between prefabricated base-
ment walls-columns/rafts, and floor to façade elements. The
Er. Ajit Vasant Bhate
Precast India Infrastructures Pvt Ltd
1
The Award winning façade elevation
of the completed structure of the
Infosys multi level car park
2 Typical architectural floor plan 3
The architectural design is inspired on
a woolen weave pattern
4 The woolen weave concept elevation
3 4
2
Infosys multi level car park 3 2017
92
5 Precast India plant which made intricate prefab projects possible
6 Bare façade element (a) and a mock up façade-spandrel connection (b)
7 Spandrel element with dowels for connection to column corbel (a) and column sides (b)
Integrated it systems
A 3D Tekla model including all reinforcement and precast
connections was made. Highly accurate production drawings
were generated from this model and the production of the
elements was carried out accordingly.
Completely in-house developed, cloud based planning and
tracking software, generated production and erection schedule
along with sequence for installation and a full-fledged data base
of elements. Other IT systems facilitated online booking of
connections are ductile [3], sturdy and unyielding. Shear forces
between spandrel and façade elements are transferred by the
monolithic corbels in the spandrels which are also interlocking
each façade element against overturning (photo 6). The ductility
[3] of connection between the façade element and building
spandrel was achieved by use of mild steel bolts to offer moment
of resistance for 1.50 m cantilevering façade element. The use
of mild steel bolts offers sufficient warning before failure in
the seismic event.
5 6a
7b
element connected to spandrel
corbel monolithic with spandrel resisting shear
spandrel element fixed on column corbel at base
and knife plates on sides of either side columns
niche in façade element
bolt going through to other side of spandrel
corbel monolithic with
column having sleeves
for spandrel dowels spandrel element fixed on column
corbel at base and knife plates on
sides of either side columns
side connection with
column to absorb torsion
spandrel dowels fixed in column corbel
6b
7a
thema
Infosys multi level car park 3 2017
93
8 Three-storey column
erection
9 Lifting frames (a) and
stacking (b) of façade
elements
10 One of the many innova-
tions: the double decker
transport system
Stacking
Long spans and critical geometry of elements (photos 9a and 9b)
were a concern while stacking. A separate special support lifting
system was designed to de-mould and stack the elements,
avoiding lifting and handling stresses thereby lifting the façade
elements delicately, but quickly.
Transportation to site
Transporting fragile elements 45 km through narrow and
choked roads was a challenge, considering the road conditions,
lifting and handling stresses. This prompted attention to
resources (RMC, trailers, cranes), logistics management
purchase orders, material management and budget tracking.
Production and quality control systems
Even the smallest details and activities were planned well in
advance before production drawings were made and unique
element IDs were generated to be able to pinpoint the life cycle
stages of each individual element from design stage up to final
installation on site.
The state of art production facility, consisting of a hollow core
slab unit, Carousel unit (for solid slabs, walls), mechanically
and hydraulically operated adjustable beam and column
moulds giving smooth surface finish, special batching plants,
tilting tables, shear cut bend lines (steel cutting), gantry cranes,
steam curing facilities, etc., produced all precast elements in
the project, with a concrete grade of M40 MPa.
All the risks and challenges like demoulding, lifting, installa-
tion, anchoring etc. were eliminated and structurally approved
by mockup tests. Sample prototypes were cast multiple times,
and representative elements were tested till failure.
Multiple tests on raw materials, load tests for representative
elements were done and certified by third party testing agencies,
before full scale production began. Each test and control greatly
helped in achieving the high quality and consistency with
regards to strength and finish, resulting in the good durability.
8
9b
10
corbel monolithic with
column having sleeves for
spandrel dowels
knife plates for side connection
with spandrel element
9a
Infosys multi level car park 3 2017
94
11 Intermediate stage of façade installation, showing a corner column
12 Interior of the fully finished structure
13 Exterior of the fully finished structure
Installation on site
The entire erection of the 3500 elements was a pre-planned
activity, even before the production planning, considering all
the major constraints at site like restricted side margin availa-
bility, limited access, availability of special tools and tackles etc.
The installation of the odd façades was accomplished with an
average erection time of 25 minutes per façade element.
For installation of TT slabs, columns, beams and other elements
of the structure, a 50MT rail mounted Liebherr tower crane was
set up on rails in the center of the building, considering element
weight and available crane capacity at the required radius (16 tons
at 48 m). 50 ton and 120 ton mobile cranes were also used.
Accuracy, tolerances and precisiom
An overall accuracy up to 15 mm without any adjustment
anywhere was achieved despite the complex nature of all the
precast elements. The 20 mm bolts in the façade element passing
through the spandrel sleeve of 40 mm, had overall tolerance of
20 mm only, including also other tolerances during erection of
foundations, columns, beams etc. This came as a result of
constant coordination and exchange between all the stakeholders
[9] including design, planning, production, transportation and
installation of all the elements. Finally, perfect coordination
between all stakeholder teams, ensured the creation of milestone
and a unique game changer in the Precast industry in India.
?
?
REFERENCES
1 BIS, I. (2000). Indian Standard ( IS ), Plain and RC-Code of
Practice. Bureau of Indian Standards.
2 Standard, I. (1893). Criteria for earthquake resistant design of
structures. Indian Standards Institution, IS, 1975.
3 BIS, I. (1993). 13920 Ductile Detailing of Reinforced Concrete
Structures subjected to Seismic Forces?Code of Practice. India:
Bureau of Indian Standards.
4 PCI Design Handbook, Precast and Prestressed Concrete (1985).
Chicago: Precast and Prestressed Concrete Institute. pp. 11-18.
5 BSI, B. S. 8110-1: 1997 Structural use of concrete?Part 1: Code of
practice for design and construction.
6 Building code requirements for structural concrete (ACI 318-08) and
commentary (2008). ACI Committee, & International Organization for
Standardization.
7 Ajit V Bhate, Jt. MD, Bhate & Raje Construction Co. Pvt. Ltd and MD,
Precast India Infrastructures Pvt. Ltd., 2010-present.
8 Precast India QAQC Manual, 2015.
9 Precast India MPFC (Meta Process Flow Chart) Document, 2015.
the economical considerations and resulted in the decision to
transport multiple elements simultaneously. The transportation
experts innovated a double decker transport assembly system
designed and fabricated as a removable attachment, ready to
shift eight façade elements per trip (photo 10). This improved
installation speed and enabled meeting the target dates.
11
12
13
thema
Infosys multi level car park 3 2017
Reacties