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Design of retaining wall
Design of retaining wall
Design of retaining wall
Design of retaining wall
Design of retaining wall
Design of retaining wall
Design of retaining wall
Design of retaining wall
Design of retaining wall
Design of retaining wall
Design of retaining wall
Design of retaining wall
Design of retaining wall
Design of retaining wall
Design of retaining wall
Design of retaining wall
Design of retaining wall
Design of retaining wall
Design of retaining wall
Design of retaining wall
Design of retaining wall
Design of retaining wall
Design of retaining wall
Design of retaining wall
Design of retaining wall
Design of retaining wall
Design of retaining wall
Design of retaining wall
Design of retaining wall
Design of retaining wall
Design of retaining wall
Design of retaining wall
Design of retaining wall
Design of retaining wall
Design of retaining wall
Design of retaining wall
Design of retaining wall
Design of retaining wall
Design of retaining wall
Design of retaining wall
Design of retaining wall
Design of retaining wall
Design of retaining wall
Design of retaining wall
Design of retaining wall
Design of retaining wall
Design of retaining wall
Design of retaining wall
Design of retaining wall
Design of retaining wall
Design of retaining wall
Design of retaining wall
Design of retaining wall
Design of retaining wall
Design of retaining wall
Design of retaining wall
Design of retaining wall
Design of retaining wall
Design of retaining wall
Design of retaining wall
Design of retaining wall
Design of retaining wall
Design of retaining wall
Design of retaining wall
Design of retaining wall
Design of retaining wall
Design of retaining wall
Design of retaining wall
Design of retaining wall
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Design of retaining wall

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  • 1. DESIGN OF CANTILEVER RETAINING WALL S
  • 2. FUNCTION To hold back the masses of earth or loose soil where conditions make it impossible to let those masses assume their natural slopes.
  • 3. TYPES <ul><li>GRAVITY WALLS </li></ul>RETAINING WALLS
  • 4. TYPES RETAINING WALLS CANTILEVER
  • 5. TYPES RETAINING WALLS COUNTERFORT
  • 6. TYPES RETAINING WALLS COUNTERFORT School of Civil Engineering-AIT SIIT-Thammasat University
  • 7. TYPES RETAINING WALLS BUTTRESS School of Civil Engineering-AIT SIIT-Thammasat University
  • 8. PARTS CANTILEVER RETAINING WALLS BACKFILL FRONT School of Civil Engineering-AIT SIIT-Thammasat University STEM or Wall Slab TOE HEEL KEY
  • 9. EARTH PRESSURES School of Civil Engineering-AIT SIIT-Thammasat University Liquids are frictionless and cohesion less. So in liquid retaining structures the pressures are directly related to the density of the liquid and head.
  • 10. y  y School of Civil Engineering-AIT SIIT-Thammasat University
  • 11. EARTH PRESSURES School of Civil Engineering-AIT SIIT-Thammasat University However, this is not true for soils: Sand, for example, when dry, acts as a frictional material without cohesion and has a well-defined angle of repose .
  • 12. EARTH PRESSURES School of Civil Engineering-AIT SIIT-Thammasat University If the same sand is now moistened, it develops a certain amount of cohesive strength and its angle of repose increases, somewhat erratically.
  • 13. EARTH PRESSURES School of Civil Engineering-AIT SIIT-Thammasat University Further wetting will break down the internal friction forces until the sand slumps and will hardly stand at any angle at all.
  • 14. EARTH PRESSURES School of Civil Engineering-AIT SIIT-Thammasat University Clay on the other hand when first exposed in situ stands vertically to considerable depths when reasonably dry, but after time will subside, depending on its moisture content.
  • 15. EARTH PRESSURES School of Civil Engineering-AIT SIIT-Thammasat University And clay, in dry seasons, gives up its moisture to atmosphere with subsequent shrinkage, so that at depths less than about 1 or 2 m it may be unreliable as a stop to react the forward movement of a retaining wall.
  • 16. EARTH PRESSURES School of Civil Engineering-AIT SIIT-Thammasat University Thus the lateral pressures from soils can vary very widely depending on the moisture content.
  • 17. EARTH PRESSURES <ul><li>PRESSURE AT REST </li></ul><ul><li>ACTIVE EARTH PRESSURE </li></ul><ul><li>PASSIVE EARTH PRESSURE </li></ul>School of Civil Engineering-AIT SIIT-Thammasat University
  • 18. PRESSURE AT REST School of Civil Engineering-AIT SIIT-Thammasat University When the soil behind the wall is prevented from lateral movement (towards or away from soil) of wall, the pressure is known as earth pressure at rest.
  • 19. PRESSURE AT REST School of Civil Engineering-AIT SIIT-Thammasat University This is the case when wall has a considerable rigidity. Basement walls generally fall in this category.
  • 20. PRESSURE AT REST School of Civil Engineering-AIT SIIT-Thammasat University RIGID
  • 21. ACTIVE EARTH PRESSURE School of Civil Engineering-AIT SIIT-Thammasat University If a retaining wall is allowed to move away from the soil accompanied by a lateral soil expansion, the earth pressure decreases with the increasing expansion.
  • 22. ACTIVE EARTH PRESSURE School of Civil Engineering-AIT SIIT-Thammasat University A shear failure of the soil is resulted with any further expansion and a sliding wedge tends to move forward and downward . The earth pressure associated with this state of failure is the minimum pressure and is known as active earth pressure.
  • 23. EARTH PRESSURES School of Civil Engineering-AIT SIIT-Thammasat University
  • 24. School of Civil Engineering-AIT SIIT-Thammasat University H H/3 
  • 25. H H/3  School of Civil Engineering-AIT SIIT-Thammasat University
  • 26. PASSIVE EARTH PRESSURE School of Civil Engineering-AIT SIIT-Thammasat University If a retaining wall is allowed to move towards the soil accompanied by a lateral soil compression, the earth pressure increases with the increasing compression in the soil.
  • 27. PASSIVE EARTH PRESSURE School of Civil Engineering-AIT SIIT-Thammasat University
  • 28. = 1/C ah School of Civil Engineering-AIT SIIT-Thammasat University  = 0
  • 29. STABILITY <ul><li>OVERTURNING </li></ul><ul><li>SLIDING </li></ul><ul><li>BEARING </li></ul>School of Civil Engineering-AIT SIIT-Thammasat University
  • 30. OVERTURNING School of Civil Engineering-AIT SIIT-Thammasat University Highway Loading (Surcharge)
  • 31. OVERTURNING School of Civil Engineering-AIT SIIT-Thammasat University Overturning Forces No Surcharge Here Full Surcharge Here Active Pressure Soil+Surcharge
  • 32. OVERTURNING School of Civil Engineering-AIT SIIT-Thammasat University Restoring Forces No Passive Pressure Weight of Soil Weight of Wall Weight of Soil (with care)
  • 33. OVERTURNING School of Civil Engineering-AIT SIIT-Thammasat University A FOS = 2 is considered sufficient Restoring Moment Overturning Moment FOS vs OT =
  • 34. SLIDING School of Civil Engineering-AIT SIIT-Thammasat University Sliding Forces No Surcharge Here Full Surcharge Here Active Pressure Soil+Surcharge H1
  • 35. SLIDING School of Civil Engineering-AIT SIIT-Thammasat University Resisting Forces H2 +  V  =Coeff of Friction Resisting Forces No Surcharge Here H2 V s1 V s2 V c1 V c2 V c3
  • 36. SLIDING without KEY School of Civil Engineering-AIT SIIT-Thammasat University A FOS = 1.5 is considered sufficient Passive Earth Pressure Force+  V Active Earth Pressure Force FOS vs Sliding =
  • 37. SLIDING with KEY School of Civil Engineering-AIT SIIT-Thammasat University Sliding Forces No Surcharge Here Active Pressure Soil+Surcharge
  • 38. SLIDING with KEY School of Civil Engineering-AIT SIIT-Thammasat University Resisting Forces V s1 V s2 V c1 V c2 V c3 No Surcharge Here H
  • 39. SLIDING with KEY Find Vertical forces acting in front and back of key School of Civil Engineering-AIT SIIT-Thammasat University V s1 No Surcharge Here V s2 V c1 V c2 V c3 RESULTANT Active Pressure Soil+Surcharge
  • 40. SLIDING with KEY School of Civil Engineering-AIT SIIT-Thammasat University Determine Pressure Distribution Under Base B B/2 e A=B S=B 2 /6 V x
  • 41. SLIDING with KEY School of Civil Engineering-AIT SIIT-Thammasat University Determine Force in Front of KEY y3=y2+(y1-y2) (B-x1)/B P1=(y1+y3) x1/2 P2=V-P1 B x1 P1 P2 y1 y2 y3
  • 42. SLIDING with KEY School of Civil Engineering-AIT SIIT-Thammasat University When Pressure Distribution Under Base is Partially Negative B B/2 e V
  • 43. SLIDING with KEY School of Civil Engineering-AIT SIIT-Thammasat University B x e V 3x Determine P1 and P2 once again P1 P2 2V 3x
  • 44. SLIDING with KEY School of Civil Engineering-AIT SIIT-Thammasat University Total Sliding Force = H1 Total Resisting Force = P1 tan  P2 + H2 Passive Earth Pressure Force Force in Front of Key Internal Friction of Soil Force on and Back of Key Friction b/w Soil, Concrete Active Earth Pressure Force
  • 45. BEARING School of Civil Engineering-AIT SIIT-Thammasat University 1. No surcharge on heel 2. Surcharge on heel There are two possible critical conditions
  • 46. BEARING School of Civil Engineering-AIT SIIT-Thammasat University No Surcharge on Heel V s1 This case has been dealt already V s2 V c1 V c2 V c3 RESULTANT Active Pressure Soil+Surcharge
  • 47. BEARING School of Civil Engineering-AIT SIIT-Thammasat University Surcharge on Heel V s1 Vs DETERMINE THE PRESSURE DISTRIBUTION UNDER BASE SLAB V s2 V c1 V c2 V c3 RESULTANT Active Pressure Soil+Surcharge
  • 48. School of Civil Engineering-AIT SIIT-Thammasat University Determine Pressure Distribution Under Base B B/2 e A=B S=B 2 /6 V x
  • 49. School of Civil Engineering-AIT SIIT-Thammasat University Compare Pressure with Bearing Capacity B FOS vs Bearing = Allowable Bearing Max Bearing Pressure
  • 50. School of Civil Engineering-AIT SIIT-Thammasat University ALTERNATELY B 2V/3x 2V/3x 3x FOS vs Bearing = Allowable Bearing Max Bearing Pressure
  • 51. END OF PART I
  • 52. BENDING OF WALL School of Civil Engineering-AIT SIIT-Thammasat University
  • 53. DESIGN OF STEM School of Civil Engineering-AIT SIIT-Thammasat University CRITICAL SECTIONS Active Pressure Soil +Surcharge Critical Section Moment Critical Section Shear d
  • 54. DESIGN OF STEM School of Civil Engineering-AIT SIIT-Thammasat University Design Moment = 1.6 ( H1 y1 + H2 y2) H1=Ca s h Surcharge = s N/m 2 H2=0.5 Ca  s h 2 y1 y2 h
  • 55. DESIGN OF STEM School of Civil Engineering-AIT SIIT-Thammasat University Design Shear=1.7(H '1+ H '2 ) H'1=Ca s (h-d) Surcharge = s N/m 2 H'2=0.5 Ca  s (h-d) 2 d h
  • 56. DESIGN OF TOE SLAB School of Civil Engineering-AIT SIIT-Thammasat University CRITICAL SECTIONS Critical Section Moment d Critical Section (Shear)
  • 57. DESIGN OF TOE SLAB School of Civil Engineering-AIT SIIT-Thammasat University Design Loads 1.6Soil Pressure 0.9 Self Wt 0.9 Soil in Front (may be neglected)
  • 58. TOE : DESIGN MOMENT 1.6(0.5 T y3) T/3 +1.6(0.5 T y1) 2T/3 -0.9 w c T 2 /2 -0.9 w s T 2 /2 T y1 y3 School of Civil Engineering-AIT SIIT-Thammasat University
  • 59. TOE : DESIGN SHEAR 1.6(0.5 T s ) y3 T s /T +1.6(0.5 T y1-0.5 d [y1/T] d) -0.9 w c T s -0.9 w s T s Ts=T-d y1 y3 School of Civil Engineering-AIT SIIT-Thammasat University
  • 60. DESIGN OF HEEL SLAB School of Civil Engineering-AIT SIIT-Thammasat University CRITICAL SECTIONS Critical Section Moment & Shear TENSION FACES
  • 61. DESIGN OF HEEL SLAB School of Civil Engineering-AIT SIIT-Thammasat University DESIGN LOADS 1.6s + 1.2  s +1.2  c Soil Pressure Neglected
  • 62. BENDING OF WALL School of Civil Engineering-AIT SIIT-Thammasat University
  • 63. MAIN REINFORCEMENT School of Civil Engineering-AIT SIIT-Thammasat University Minimum 75 mm Clear Cover
  • 64. ACI CODE SECONDARY STEELS School of Civil Engineering-AIT SIIT-Thammasat University ACI Minimum SLAB ACI 14.3.3 ACI 14.3.2
  • 65. END OF PART II
  • 66. DRAINAGE School of Civil Engineering-AIT SIIT-Thammasat University Sand + Stone Filter Weepers Or Weep Holes
  • 67. DRAINAGE School of Civil Engineering-AIT SIIT-Thammasat University Drainage Pipes f 100-200 mm @ 2.5 to 4 m
  • 68. DRAINAGE (Alternate) School of Civil Engineering-AIT SIIT-Thammasat University Perforated Pipe Suited for short walls
  • 69. End of Part III END OF PART III

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