Engineering today is multidisciplinary and could primarily be divided into two main divisions; Mechanical Engineering and Civil Engineering.
Mechanical Engineering is defined as a branch of engineering concerned primarily with the industrial application of mechanics and the production of tools, machinery, and their products.
The use of tools by pre-historic man is seen as the first application of engineering mechanics by him while today it is mainly of managing the rotary motion of machine mechanisms aiding man in his day to day affairs.
Civil Engineering is a professional engineering discipline that deals with the design, construction, and maintenance of the physical and naturally built environment, including works like roads, bridges, canals, dams, and buildings.
This could be simplified as construction of structures and habitats essential for the comfort of mankind……….and could be shown as his ability to control lines and levels maintaining stability and equilibrium.
Much have been the challenges in my life as a civil engineer…. and the Pallekelle Cricket Stadium built in 2003/2004 in Kandy Sri Lanka was a very interesting and a challenging one. It being the intricacy of the building laid on curves and radials radiating from the center of the batting crease. Generally in a standard building the building grids are laid square at 90 degrees controlled in a symmetrical way.
A typical square grid controlled building plan. Numeric grids in the vertical direction against the alphabet grids in the horizontal.
This is the most common form of building control used in a two dimensional plane.
The third dimension being the vertical is controlled by the level. This is generally based to the sea level or at times on an arbitrarily derived datum.
Pallekele stadium was of the latter type as shown alongside with the numeric grids on curves with different radii, while the alphabet grid was on radii originating from the center of the pitch.
The complication of controlling a construction of this type is self explanatory to the reader.
It is in the mind of the Architect that the shape and operation of the system is originated. He in return provides the design of his idea in 3 D and 2 D form on paper for the Structural Engineer to design and stiffen his idea to real form on ground with the use of construction material….be it stone, earth, timber, metal, concrete, fiberglass or the combination of all this.
The Pallekele Stadium is a replica of the Centurion Park Stadium in South Africa designed by the architectural firm “Tilka of South Africa”. Tilka were the architects for the Pallekele stadium as well assisted locally by the Engineering Consultants Ltd [ECL] . The project was implemented by Zarara Sports Ltd a local company formed for the purpose. The company would own and operate the facility once completed.
The land leveling and the ground formation had been done by other parties when the International Construction Consortium Pvt Ltd [ICC] was contracted to construct the stadium. I as the Coordinating Engineer had a leading role to play with many other engineers on site in getting this curved engineering challenge to its present state; a brilliant piece of fare-faced concrete finished structure in Sri Lanka.
The initial approach to the construction was discussed with all the mentioned parties and the Structural Design Engineer Mr Vasantha Ratnayake. It was concluded that the horizontal load bearing structural component the beams will be positioned in straight lines meeting vertical load bearing members the columns.This was to ease the complication on curved design calculations and other onsite construction constrains. The straight beams are thus located hidden and blended into the curved fascia lines.
The challenge then was in getting the molds or the concrete form-work in the shape of the curves of very long radii.
The intricate mathematical theory learnt long back was used in the design of the form-work. If you still remember your advanced mathematics……any curve could be derived as a combination of a series of minute straight lines.
Remember dy/dx in Calculus . It was this theory that was sued in the construction of form-work and other molds as practiced in the constriction industry.
These pictures show the theory of the definition that a curve is a combination of small straight lines. Also geometrical theorems learnt way back came in use to mark out the curves in turning out frames to hold the small battens.
It is not possible to use primary drawing instruments when working with radii over 100 meters. Remember Theorem 32: the angle at the center is twice the angle at the circumference is used to mark out the curves in such cases.
Today the architect will not settle for a battened curve on a building and in modern times other malleable material is used to achieve a better surface finish. In Pallekele we used 3 mm thick steel plates welded on to angle iron frames bent to curvature derived as above.
Of course with all this theory used one needs to mange your project proper with extreme attention given to quality control by maintaining you lines and levels with strict checks on plumb-lines for verticality etc. Strengthening your forms in place so as to carry the heavy dead load of green concrete before it sets is also very vital. Concrete commences hardening from about an hour from pouring to 28 days to attain its maximum self standing properties with steel reinforcement.
The pictures below will explain the process that was undertaken to give you a fantastic stadium to watch cricket with the spectator being able to see the ball in any location on the ground without having to stand from his seat.
Some of the items built in the period 2003/2004 may have been knocked down now as the work on the original stadium came to a halt in 2004 due to financial constrains experienced by Zarara Sports. The facility was then transferred to Sri Lanka Cricket and the balance work was to be completed for the Cricket World Cup 2011 by Sri Lanka Cricket through the State Engineering Corporation of Sri Lanka where certain modifications were done to the original plan.
The original fabric roof that was designed was substituted with a Zink Aluminium [ZnAl] roof. Part of the roof fabric that came into the country then is now used as ground covers during inclement weather ……….funny isn't it……. but then they are used against the rain element anyway.
Skilled workmen busy fixing form-work for concrete after fixing steel reinforcement
The highest platform for the camera in line with the center of the pitch
Architecture to be enjoyed by those with a trained eye
|A square platform for two disabled spectators - probably not there anymore|
The intricacy of construction that many don’t get to see
|Form-work placed for a staircase|
The intricate layout of press box communication conduits for cabling
Panoramic view of the stadium as completed in 2004
Definitely a challenging project which was interesting.......a feather in my cap!