Distributed Loads

Strip Loads (L/B > 9) Wall Footings Embankements

Circular Loads (R) Storage Tanks

Rectangular Loads (BxL) Spread Footings Mat Foundations

Combination Loads

Strip LoadFig 5.12

p/q= fn {2x/B, 2z/B} See Table 5.4

Stress Isobars

Fig 5.14

Example 5.5

q=200 kN/m2, B=6m, z=3m

Circular LoadsFig 5.15

/q=1-1/[(R/z)2+1]3/2

/q = fn {z/R} (Table 5.5)

Circular LoadsFig 5.16

Rectangular LoadsFig 5.17

/q = I2

I2 = fn {m=B/z, n=L/z} Fig 5.18

Variation of I2

Rectangular LoadsFig 5.19

A/ q = (I 2-1+ I 2-2+ I 2-3+ I 2-4)

Principle of Superposition

Stress Isobars

Combined AreasFig 5.22

Combined AreasFig 5.23

Newmark’s Chart

z

= (IV) q M

Example 5.7

Example 5.7

Z=3m

=(IV) q M

= 0.005 (600kN/9m2)(48.5) = 17.78 kN/m2

Newmark’s Chart

Rectangular LoadsFig 5.19

C’