Check Beam Shear Bending moment design 2 5
Check Beam Shear
Bending moment design 2. 5 m Short direction 245 166 245
Central band ratio = Central band of short direction = 0. 83 As = 0. 83 (10. 1)=8. 6 cm 2
Footing Design Part II Combined footing
Example 1 Design a combined footing As shown
Dimension calculation The base dimension to get uniform distributed load 2000 k. N 800 k. N 1200 k. N A x 1=0. 2 m x 2=6. 2 m x 800(0. 2)+1200(6. 2)=2000(x) x = 3. 8 m 800 k. N 1200 k. N Try thickness =80 cm 2 x =7. 6 m
Area required
Check for punching Shear d = 730 mm 1. 13 m A 0. 765
B
Draw S. F. D & B. M. D Stress under footing = 190 *1. 8 = 342 k. N/m
Check for beam shear b = 1800 mm, d = 730 mm
Bending moment Long direction
Bending moment Short Under Column A direction
Under Column B Shrinkage Reinforcement in short direction
Footing Design Part III Combined footing, strip footing, & Mat foundatio
Example 2 Design a combined footing As shown
Dimension calculation The base dimension to get uniform distributed load 1950 k. N 1200 k. N 750 k. N A x 1=0. 2 m x 2=4. 2 m x 750(4. 2)+1200(0. 2)=1950 (x) x = 1. 75 m
Area required
Check for punching Shear h= 750 mm d = 732 mm A B 2=1 m B 1=4 m
B
Draw S. F. D & B. M. D
Empirical S. F. D & B. M. D m Convert trapezoidal load to rectangle Mmax Clear distance between column B in moment design = ave. width = 2. 5 m
Check for beam shear d = 665 mm b Y=1. 5 m x 4 m 1 m
Bending moment Long Top Bottom direction
Bending moment Short Under Column A direction
Under Column B Shrinkage Reinforcement in short direction
Reinforcement details
Example 3 (Strip footing) Design a combined footing As shown
Dimension calculation The base dimension to get uniform distributed load 3040 k. N 800 k. N 1280 k. N 960 k. N A Assume L 1=0. 6 x 1=5. 2 m x 2=10. 7 m x 800(0. 6)+1280(5. 1)+960(10. 6)= 3040 (x) x = 5. 65 m, 2(x)=11. 3 m L 2=11. 3 - (10. 6)=0. 7 L 2
Check for punching Shear h = 700 mm d=630 mm Example B You can check other columns
Draw S. F. D & B. M. D Stress under footing = 195 *1. 8 = 351 k. N/m
Check for beam shear b = 1800 mm, d = 630 mm
Bending moment Long Design Short direction as example 1 (lecture 11)
Reinforcement details
Mat Foundation
Check for punching Shear
General Example, Ref. 2 Modified load
General reinforcement details
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