Introduction to advanced TUNNEL Formwork system: Case study of ‘Rohan - Abhilasha’

International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395 -0056
Volume: 04 Issue: 03 | Mar -2017 www.irjet.net p-ISSN: 2395-0072
© 2017, IRJET | Impact Factor value: 5.181 | ISO 9001:2008 Certified Journal | Page 294
Introduction to advanced TUNNEL Formwork system: Case study of
‘Rohan - Abhilasha’
Mr. Manas A. Shalgar1, Mr. Tejas D. Aradhye2
1. Post graduate student, Department of Civil Engineering, Maharashtra Institute of Technology, Pune
(Maharashtra, India).
2. Civil Engineer (ME-Construction and Management), Rohan Builders India Pvt. Pune.
(Maharashtra, India)
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Abstract: Now a day construction industry is becoming very
time conscious. Time (i.e project completion time) or
duration of the project is very important factor in
construction industries these days. The quote “ Time is
money” is becoming truth, because time loss is ultimately
money loss. Also as current situation of labour availability is
very less, so industry should move from labour oriented to
machine oriented. And formwork is best factor where we
can move from labour to machine. Formwork perform key
role in construction, in time as well as costs. Only formwork
costs nearly 25% of total project cost. We know the
complications & wastage in construction by using
conventional formwork system. So we moved to formworks
like mivan, aluminium for simplicity and good finish, but it is
not enough. As we discussed time factor, by using systems
like mivan, aluminum off course there is time saving but not
up to that extent. So there is new emerging technology
named TUNNEL formwork. Which is much beneficial than
that of aluminium or mivan formwork. This paper describes
the introduction to advanced TUNNEL formwork.
Key Words: TUNNEL formwork, slab cycle, economy,
time saving.
1. INTRODUCTION
Indian construction is known for its use of conventional/
typical formwork system, and it has not adapted advanced
formwork systems in RCC works compared to developed
nations. Formwork plays vital role in RCC framed / load
bearing structures. Formwork is a mould or die used to
shape and support the concrete until it attains sufficient
strength to carry its own weight. The formwork is a kind
of “baking tin”, which holds the concrete until it hardens to
attain the required shape and size.
Formwork constitutes 30% of the cost and 60% of the
time in concrete construction. Quality of concrete finish
and soundness of concrete depends very much on the
formwork system. Formwork should be properly
designed, fabricated, and erected to receive fresh concrete.
If formwork is not done properly the desired shape of
concrete is not possible. When concrete is compacted, it
exerts pressure and the formwork must be strong and
stable to take this pressure. The form should be leak proof
to retain the concrete & slurry.
Advanced Tunnel formwork identified to be suitable for
Indian conditions for mass construction, where quality
and speed can be achieved at high level. The speed of
construction by this system will surpass speed of most of
the other construction systems. The labour in coordination
with heavy machineries (eg. tower crane) handles this
method effectively to speed up the construction, to assure
quality control and durability. Adoption of this system
reduces overall cost of the structure. This paper mainly
focuses on advanced tunnel formwork systems, its
components, working cycle and its benefits based on
speed and economy.
2. OBJECTIVE
Objective of this paper is to introduce Indian construction
industry to advanced TUNNEL formwork systems which is
rapid and if used effectively ultimately economical based
on,
a. Components
b. Working cycle
c. Economy.
d. Benefits and disadvantages.
3. THEORETICAL CONTENT
3.1 Current trends in formwork systems.
At present in Indian construction industry various types of
formwork systems being used. Based on type of material,
purpose of use and method of erection formwork systems
listed as follows.
1. Conventional formwork.
2. Climbing formwork system.

3. Slip formwork system.
4. Permanent formwork.
5. Mivan/ Aluform/ Aluminium formwork
6. Tunnel formwork.
3.2 Introduction To Tunnel Formwork
Tunnel form is nothing but it is a box sized steel fabricated
form which allows structure to be casted monolithic i.e. to
cast RCC walls and slab in single continuous pour. The
formwork system is supported with hot air blowers which
accelerates the setting of the concrete. So that one can
achieve one slab in one day i.e. 24 hours slab cycle.
This system becomes more economical for symmetric
construction like mass housing projects and contains huge
quantum of symmetrical work.
Figure 1 :- Tunnel Form and its components
3.3 Components
Components of tunnel formwork are detailed as follows:-
1. Vertical, Deck and back panel: Retain fresh concrete until
it gets set and cured.
2. Stripping platform, gable end platform and working
platform: Provided for movement and working of labors
and machinery and also for stripping out tunnels.
3. Push-pull props, wheeled prop: To maintain line and
level of tunnel.
4. Lifting triangle: Placed at centre of mass of tunnel form
deck panel for lifting by tower crane.
5. Kicker form: Provided as starter formwork at slab level
to maintain position of next level tunnel form.
6. Slab stop end, Wall stop end: Provided as stopper to
retain fresh concrete up to wall and slab line.
7. Block outs: Block outs are fixed at vertical panels to
provide door, window and ventilation windows in walls.
Figure 2 :- Tunnel Form at Site
3.4 Working Cycle
Working Cycle of Tunnel form system is mainly divided
into three parts. Viz
I. Striking Of Formwork.
II. Setting Of Formwork.
III. Concreting Operation.
These 3 activities are divided as follows
a. Formwork panels are cleaned and oiled at the time of
Deshuttering itself
b. Ready wall reinforcement are placed in position and
after placing beams are fitted manually.
c. Forms are placed in position guided by concrete starters
d. Slab reinforcement mesh and electrical-plumbing
conduits are fixed in reinforcement.
e. Walls, slab along with kickers (starters) are casted in one
continuous pour.
f. Formwork panels are ready to de shutter and shift to next
location by tower crane.
3.5 Economy
Basic cost considerations in economy of tunnel formwork
are follows
1. Depreciation cost of material, heavy machinery
2. Machinery operational cost.
3. Daily cost expenditures on labour
4. Supervision cost.
Though initial investment in material and heavy machinery
is very high due to reduced slab cycle and more reuse
potential for large multistoried projects tunnel formwork
becomes ultimately economical. As construction speed is
very high than that of other formwork systems, As
turnover is more within a short period, returns of
investment made will be early. Also good quality finish
results in minimizing labour and material cost in finishing
items and requires less finishing treatment.
Precast element is one of the critical activity at the time of
using tunnel formwork, it results in increased productivity

with fabulous architecture view after erection at very short
period of time which again results in time and cost saving.
Figure 3 :- E1 Building During Tunnel Casting
3.6 Advantages and disadvantages
3.6.1 Advantages
I. Time Advantages
1. A production cycle of 1-3 days can be achieved.
2. Depending on the production speed of load bearing
system succeeding production activities in the building can
also be accelerated.
3. The project can be completed in a short time compared
to traditional construction systems.
4. Due to accelerated production, effects of climatic
conditions on productivity are minimized.
II. Quality Advantages
1. Higher precision in production of walls and slab units
(1/1000 deformation is allowed and can be achieved)
2. Smooth surfaces for the walls and slabs are obtained that
can be covered with wallpaper right after easy and quick
cleaning.
3. Standard dimensions for the other components such as
carpet, windows, and doors can be applicable due to strict
dimensions of load-bearing system elements.
III. Cost Advantages
1. Formwork cost per m2 (or per housing unit) can be
reduced by using formwork up to number of times.
2. Due to smooth surfaces, walls and slabs do not need any
additional finishing such as plaster.
3. Early completion of project provides financial
opportunities such as rental incomes.
4. Repetitive nature of buildings provides effectiveness in
production and minimization of labor costs.
3.6.2 Disadvantages.
1. Investment cost of formwork system increases
formwork cost per m2 if project is small sized.
2. A continuous and fast cash flow that complies with the
speed of production is essential.
3. Due to high production speed management-related
functions are vital. Coordination problems cause
remarkable delays in schedule.
4. Skilled labor force is needed compared to traditional
systems.
5. Equipment costs are relatively higher due to the cranes
that are needed by each block.
6. Tunnel formwork system is not convenient for some
building types such as music halls, theaters, etc., that
contains large spans.
7. Lowered slab is not allowed since it prevents the
removal of formwork, suspended ceiling is required.
8. Load bearing walls must be designed continuously on
the same axial system due to the resistance requirements
against horizontal forces.
9. Basement stories cannot be constructed by using tunnel
formwork system; removal of formwork is not possible
10. Tower cranes are required for the erection, removal
and carriage of formworks, scaffolds, and pre-cast
components.
11. A workshop is required for the production of precast
components such as stairs, parapets, and walls.
12. A crane can serve max. 2 blocks at the same time
Movement of cranes has difficulties according to some
topographic conditions.
4. CASE STUDY
1. Name of organization: Rohan Builders India Pvt Ltd.
2. Name of project: Rohan Abhilasha.
3. Location: Wagholi- Lohgaon road, Pune.
4. Type of project: Real estate.
5. Scope of work considered:
I. Rohan Abhilasha ‘E- Block’. E block consist of four 14
(2G+12) storied towers.
II. Underground water tank (Master Balancing reservoir)-
Capacity 700000 Liters
III. Transformer room.
6. Area of RCC construction: 32000 Sq. Ft
7. Type of formwork used:
I. Up to 2nd parking level: Conventional formwork
II. 3rd to 14th floor : Tunnel formwork.
8. Contractor hired for execution: BUYUK ISKENDER,
Ankara, Turkey.
9. Architectural consultant: Mindspace architects,
Banglore.
10. RCC consultants: JW Consultants, Pune.
Figure 4 :- E1 Building in finishing stage

5. CONCLUSIONS
Construction is a complex and risky process requiring
extensive planning, engineering, procurement, and
construction management. When all of these activities
operate in concert with each other, the result is a
successful project. Formwork is key component of any
structure, quality of construction is directly depend on
formwork used. There are various types of aluminium
formwork used in construction industry from
conventional formwork to special forms.
Real estate construction industry has a reputation of not
begin very technologically sophisticated, generally lagging
in innovation, construction techniques & management. But
now a day’s lot of research is carried out in this sector,
advanced TUNNEL formwork is good examples of this
innovation. We can achieve 1-3 days slab cycle by TUNNEL
formwork system.
Heavy machinery and on site management are critical
factors in implementing tunnel formwork. Also high cash
flow management is essential to carry out work properly.
Coordination problem cause remarkable delay in schedule.
Also after studying the tunnel formwork system it can be
concluded that, though initial investment and per day
operational cost in TUNNEL formwork is more, due to
more reuses and reduced slab cycle time TUNNEL
formwork works out ultimately economical. Also returns
from initial investment regained due rapid completion of
project Hence in long term consideration TUNNEL
formwork system is beneficial. As turnover is more within
a short period, returns of investment made will be early.
And hence when considered for longer period of time over
large area, tunnel formwork works out to be economical.
Figure 5 :- Transformer room using Tunnel Form
6. FUTURE SCOPE OF WORK
This research could be used as an avenue for other
researchers to conduct additional studies of various
formwork systems. This study is limited as technique used
is relatively new to Indian construction industry. Further
study could be done in following
1. As this study is mainly aims for cost and slab cycle time
of formwork systems, one can focus on increase in
productivity by using advanced techniques in formworks.
Use of tower crane plays critical role in reducing slab cycle
time, the study of tower crane and its optimum use also
can be the research area for researchers.
2. Though tunnel formwork system involves heavy
investment in procurement, heavy machineries,
specialized expert labour it becomes uneconomical. In
case project involves more than 20 storied building over
large area, total economics may change considerably.
However this aspect will require further study to arrive at
conclusion.
3. At present only RCC items for towers are taken into
consideration & respective time and cost to complete
same is worked out using tunnel formwork and Aluform.
The scope of the project work is limited to above items
only. There is further scope available when all the items of
work are completed for these towers, overall economy can
be worked out considering cost incurred against the
expected returns at market value.
REFERENCES
[1] Tejas D. Aradhye and Prof. Emeritus M. R.
Apte”‘STUDY OF ADVANCED TUNNEL FORMWORK
SYSTEM IN HIGH RISE BUILDING” eISSN: 2319-1163 |
pISSN: 2321-7308
[2] Yaser Sotoudeh, mozhdeh salehi, saeed moradzadeh,
homayoon taghipoor and meisam behboodi ” Building
technology for mass concrete Tunnel form method”
Advances in Environmental Biology, 7(9): 2190-2194,
2013 ISSN 1995-0756.
[3] Dunne group ltd. Cellular construction using tunnel
form, Dunne Group Ltd Tunnel Form 2009
[4] MESA imalat, “Modular Tunnel Formwork System:
User Manual”,
[5] Larson & turbo building structure competency centre,
“Hand Book on Foundation, Formwork, Rebar &
Concrete.
[6] Dilek Tezgelen and Ozgul Yilmaz Karaman,
“Evaluation of user comfort in tunnel formwork
housing :Izmir as a Case Study” , Archnet-IJAR,
International Journal of Architectural Research 2014.

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