The document discusses a seminar on studying the behavior of hyperbolic cooling tower shells with pipe openings using a 1:50 scale model subjected to seismic loads. Hyperbolic cooling towers are large reinforced concrete structures that extract heat from water to cool it. The seminar focuses on analyzing a scaled down model of a cooling tower subjected to earthquake loads. Sensors are placed on the model to measure strains and deflections under simulated seismic conditions to understand how the structure responds.

1. SEMINAR ON
TO STUDY TH E B EH A VIOUR OF H YP ERBOLIC
COOLING TOWER SH ELL WITH PIPEOPENING S
SC A LEDOWN MODEL OF 1:50 SUBJECTED TO
SEISMIC LOA DS
UNDER THE GUIDENCE OF,
SYEED SULAIMAN
(Associate. Professor)

2. HYPERBOLIC COOLING TOWER
 Hyperbolic cooling towers are large, thin shell reinforced
concrete structures which contribute to environmental
protection and to power generation efficiency and reliability.
 Hyperbolic reinforced concrete cooling towers are widely
used for cooling large quantities of water in thermal power
stations, refineries, atomic power plants, steel plants, air
conditioning and other industrial plants.
 Cooling tower -Extracts waste heat to the atmosphere
through the cooling of a water stream to a lower
temperature

3. FIG : GROUP OF COOLING TOWERS

4. TYPES OF COOLING TOWER
 NATURAL DRAFT COOLING TOWER:
 The natural draft or hyperbolic cooling tower makes use of the
difference in temperature between the ambient air and the hotter
air inside the tower.
 As hot air moves upwards through the tower (because hot air
rises), fresh cool air is drawn into the tower through an air inlet at
the bottom.
 Due to the layout of the tower, no fan is required and there is
almost no circulation of hot air that could affect the performance.

5. NATURAL DRAFT COOLING TOWER
 These cooling towers are mostly only for large heat
duties because large concrete structures are expensive.
 There are two main types of natural draft towers:
 1. Cross flow tower : air is drawn across the falling
water and the fill is located outside the tower
 2. Counter flow tower : air is drawn up through the
falling water and the fill is therefore located inside the
tower, although design depends on specific site
 conditions.

6. FIG :CROSS FLOW TOWER AND COUNTER FLOW TOWER

7. MECHANICAL DRAFT COOLING TOWER
 Because of their huge shape, construction difficulties and cost, natural
draft towers have been replaced by mechanical draft towers in many
installations.
 Mechanical draft towers have large fans to force or draw air through
circulated water.
 The water falls downwards over fill surfaces, which helps increase the
contact time between the water and the air.
 There are two different classes of mechanical draft cooling towers:
 1. Forced draft
 2. Induced draft

8. COMPONENTS OF COOLING TOWER
The most prominent component of a natural draft
cooling tower is the huge, towering shell.
This shell is supported by diagonal, meridional, or
vertical columns bridging the air inlet.
 In order to achieve sufficient resistance against
instability, large cooling tower shells may be
stiffened by additional internal or external rings.
These stiffeners may also serve as a repair or
rehabilitation tool.

9. FIG : FABRICATION OF SUPPOSTING COLUMANAND
CLIMBING CONSTRUCTION OF SHELL

10. COOLING TOWER MATERIALS
1. Galvanized steel :
The most cost-effective material of construction for cooling tower
offers a substantial amount of protection as compared to the
lighter zinc thickness used several decades ago.
2. Stainless steel:
Type 304 stainless steel construction is recommended for cooling
tower that are to be used in a highly corrosive environment.
3. Fiber Reinforced plastic towers:
 Currently the first growing segment of the cooling tower market
is structure built with FRP sections.
 This inert inorganic material is strong, light weight, chemically
resistant and able to handle a range of PH values fire-retardant.
 FRP can eliminate the cost of a fire protection system, which can
equal 5-12% of the cost of a cooling tower.

11. ADVANTAGES OF COOLING TOWER
 1. Light weight, high strength — may reduce support requirements
 2. Corrosion resistant — a good match for the cooling tower
environment
 3. Long-lasting — lower lifetime cost than traditional building
materials
 4. Easy fabrication — weighs less to transport and is quick and easy to
install
 5. Nonconductive and non sparking — won’t conduct electricity and
contains no metal.
 7. Low thermal conductivity — does not easily conduct heat or cold
 8. Industry commitment — Bedford is a member of the Cooling
Technology Institute

12. DESCRIPTION OF 1:3 SCALE MODEL
The model consisted of six segments; each segment
was3.05 m (10 ft) wide, 1.67 m (5 ft-6 5/8 in.) long and
externally post tensioned together .
Each end segment is provided with an end diaphragm
101.6 mm (4 in.) thick
The model thus has an overall length of 10.36 m (34 ft).
To reduce the volume of the connection between the
shell and the deck ,the top surface of the deck was
fabricated tangent to the bottomsurface of the shell
leaving the middle part of the shell flat.

13. Segment Fabrication
 For fabrication of the shell-bridge model, a reusable wooden form was
constructed. The segments were cast vertically.
 Handheld vibrators as well as form vibrators were used to consolidate
the concrete in the forms.
 In the first segment, however, large voids in the shell portion of the
cross section were observed after stripping the form. These voids were
caused by air trapped inside the forms
 To avoid trapping air while casting the remaining segments,the forms
were provided with a grid of 3.18 rom (118 in.)diameter holes at
approximately 127 rom (5 in.) on centers,thus permitting the air to
escape.

14. MODEL TEST AND INSTRUMENT
 The model was instrumented using 61 mm (2.4 in.) longstrain
gauges mounted on the concrete surfaces.
 These gaugeswere positioned to measure the longitudinal and
transversestrains at several longitudinal and transverse sections.
 Strain gauges were also mounted on the posttensioningtendons
and on the two truss elements that connect the curband the edge
beams.
 To determine vertical deflections at several critical
locations,direct current displacement transducers (DCDT)
wereplaced along the curbs, edge beams, and across the width
ofthe model at midspan.

15. RESPONSE-SPECTRUM SEISMIC ANALYSIS
 This method is presented for a simplified seismic analysis of
nonlinear multidegree-of-freedom structures.
 The method represents an improvement over an earlier attempt to
extend the use of the conventional response-spectrum method to
nonlinear structures.
 It involves the computation of their natural frequencies and
modeshapes on the basis of their initial elastic properties
.
 The procedure is formulatedfor plane rigid frames, but limited to
elastoplasticforce-deformation behavior

16. FACTORS INFLUENCING RESPONSE SPECTRA
The response spectral values depends upon the following
parameters,
I) Energy release mechanism
II) Epicentral distance
III) Focal depth
IV) Soil condition
V) Richter magnitude
VI) Damping in the system
VII) Time period of the system

17. FACTORS INFLUENCING RESPONSE SPECTRA
The response spectral values depends upon the following
parameters,
I) Energy release mechanism
II) Epicentral distance
III) Focal depth
IV) Soil condition
V) Richter magnitude
VI) Damping in the system
VII) Time period of the system

18. SHAKE TABLE
 The shake table is an indispensable testing facility for development of
earthquakeresistanttechniques.
 A shaking table is a platform excited with servo-hydraulic actuators
to simulate different types of periodic and random motions, such as artificial
earthquakesand other dynamic testing signals of interest in the laboratory.
 This is the onlyexperimental technique for direct simulation of inertia forces,
which can be used to simulate different types of motion such as recorded
earthquake ground motions, harmonic motions,sine sweeps (increasing,
decreasing), Sine, Random etc..
 Shaketable test results enhance further the understanding of the behavior of
structures andcalibration of various numerical tools used for analysis.

19. MAJOR PARTS OF SHAKE TABLE

 SHAKE TABLE WITH LINEAR RAIL GUIDE
 ACTUATOR ASSEMBLY UNIT
a) Actuator with Servo valve
b) Load Cell
c) Displacement Transducer
 HYDRAULIC POWER PACK
 ELECTRICAL CONTROL CABINET : Consisting of electrical
components like :-
(1) Contactors
(2) Time delay relays
(3) Power inlet points
(4) Indicating lamps(RYB)
(5) Temperature Controller

20. CONCLUSION
 A shake table can be used to test the resistance of structures to
shaking.
It is evident from the sysmic analysis the principle stress observed to
be least.
It can also be used to demonstrate the sensitivity of structures of
different heights to the frequency of the ground motion.
The use of shake tables to demonstrate earthquake hazards largely has
been pioneered by the earthquake engineering community, which
possesses considerable experience in this area.
If the dimension is less deflection is less and if the dimension is more

21. REFRENCES
1) G. Murali, C. M. Vivek Vardhan and B. V. Prasanth Kumar ReddyRESPONSE OF
COOLING TOWERS TO WIND LOADS, ARPN Journal of Engineering
andApplied Sciences
2) D. Makovička, Response Analysis of RC cooling tower under seismic and wind
storm effect, Acta Polytechnica Vol. 46 No. 6/2006.
3) A. M. El Ansary, A. A. El Damatty, and A. O. Nassef, Optimum Shape and Design
of Cooling Towers, World Academy of Science, Engineering and Technology 60
2011.
4) R.L.Norton, & v.i Weingarten, the effect of asymmetric imperfections on the
earthquake response of hyperbolic cooling towers.
5) Shailesh S. Angalekar, Dr. A. B. Kulkarni, Analysis of natural draught
hyperboliccooling tower by finite element method using equivalent plate method.
6) IS: 11504:1985, Criteria for structural design of reinforced concrete natural draught
cooling tower, New Delhi, India: Bureau of Indian standards.