THOUGHTS ON STRUCTURAL ENGINEERING PRACTICE

1. THOUGHTS ON STRUCTURAL ENGINEERING PRACTICE UĞUR ERSOY Bogazici University, Civil Engineering Dept. Istanbul - Turkey Presentation atUniversity of Texas and Purdue University November 2008

2. TheMausoleum at Halicarnassus

3. TheTemple of Artemis

4. Bozdogan Aqueduct (370 A.D.) • Longest Waterline = 240 km, 149 mi • From Stranca Mountains to İstanbul

8. St Sophia, İstanbul

9. Selimiye Mosque Edirne

10. CIVIL ENGINEERING PRIOR TO 18 th CENTURY: ARCHITECTURAL AND CIVIL ENGINEERING WORKS WERE DONE BY THE SAME CRAFTSMEN. I WOULD CALL THEM : “MASTERS” OR “BUILDERS”

11. MAIN TOOLS USED BY EARLY BUILDERS: -PAST EXPERIENCE -THEIR OWN EXPERIENCE -ENGINEERING INTUITION

12. TECHNOLOGY (FromGreek) • TECHNE = ART , CRAFT • LOGOS = SCIENCE

13. SOMEONE HAS SAID THAT THE THEORY OF STRUCTURAL DESIGN IS BUILT BYATTRIBUTING IMPOSSIBLEPROPERTIES TONON-EXISTENT MATERIALS !!! Hardy Cross

15. 1400 CALCULATED deflect. P (Rotation = 0) 1200 15 mm P (Newtons) 1000 600 mm 800 d=8 mm MEASURED 600 CONCRETE BLOCK 400 200 0 0,0 0,5 1,0 1,5 2,0 2,5 3,0 3,5 4,0 4,5 5,0 Deflection (mm) P (Newton)

20. HISTORY OF SCIENCE IS FULL OF BEAUTIFUL THEORIES, BUTCHERED BY SMALL UGLY FACTS ! Sir S. Thomas

24. 450 400 TENSILE STRENGTH (psi) 350 300 250 200 150

25. TENSILE STRENGTH OF CONCRETE: fct = 4 (f’c)0.5 (In British units) TO EXPRESS THIS EQUATION IN “SI” UNITS, DIVIDE THE CONSTANT BY THE SQUARE ROOT OF 142.  4.0/(142)0.5 = 0.33567  EQUATION EXPRESSING THE TENSILE STRENGTH AS A FUNCTION OF COMPRESSIVE STRENGTH BECOMES, fct = 0.33567 (f’c)0.5 !!!!!!! ( SI units)

27. THE GREAT TRUTHS OF ENGINEERING ARE SIMPLE... AN ENDLESSLY COMPLEX PRESENTATION OF AN ENGINEERING FACT INDICATES COMPLICATION IN THE BRAIN OF THE PROPOUNDER RATHER THAN COMPLEXITY OF NATURE. Hardy Cross

28. Building Model ANALYSİS FILTER DECISION

29. THE ASSEMLY CAN NEVER REPLACE THEBRAIN THAT HAS CREATED IT ! MACHINES,METHODS AND SYSTEMS CANNOT BE A SUBSTITUTE FOR MEN Hardy Cross

30. METHODS OF ANALYSIS ARE OFTEN VERY FORMALISTIC, LIKE A SAUSAGE GRINDER. IF CERTAIN NUMERICAL DATA ARE FED INTO ONE END OF THE ANALYSIS AND A CRANK IS TURNED, A LOT OF LITTLE SAUSAGES (moments, shears, deformation etc.) COME INEVITABLY OUT OF THE OTHER END OF THE MACHINE. IT WORKS QUITE SMOOTHLY; IN FACT IT WORKS WITH DECEIVINGSMOOTHNESS. BECAUSE THE SAUSAGES SEEM UNIFORM AND REGULAR, IT IS OFTEN ASSUMED THAT THE MEAT CAN NOT BE SPOILED. Hardy Cross

31. IT IS IMPORTANT TO KNOW THE LIMITATIONS OF KNOWLEDGE AND ASK QUESTIONS, SIMPLE QUESTIONS, THAT MAY OPEN UP HOLES THROUGH WHICH LIGHT CAN FILTER INTO OUR DARK ROOMS. Hardy Cross

34. PLASTIC HINGE: ELASTO-PLASTIC BEHAVIOUR ROTATION UNDER CONSTANT MOMENT Mp Mp = SECTION CAPACITY

37. Md, depends on Mr

39. (Revised) (Linear Analysis) IF IF

41. Elastic Analysis Yielding in column 1

44. To2 1 o1 o1

46. Wrong detailing Better detailing