Stress Distribution in Soil

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Stress Distribution in Soil

• Chapter 6

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March

• 11 - Ch. 6 Homework Ch 5 and 6 due Fri.
• 13 - Dewatering Handout
• 18 - Test 2
• ACI Mix design concrete lab
• Concrete Construction lectures
• Ch. 5, 6 and Dewatering Handout
• 22 - Concrete Test Lab
• 25 - Ring Power Field Trip

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Stress in soil

• Vertical load of 1-ton applied to a column of
  1-sq ft in cross-sectional area. Pressure on
  soil surface of 1 ton/sq.ft.
• Pressure or stress extends downward and outward
  within the soil where the load is applied.

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Vertical Pressure - concentrated load

• Westergaard Equation
• q vertical stress, at depth z, at horizontal
  distance r, from concentrated load Q
• simplification eq. 6-4
• Boussinesq Equation
• q vertical stress, at depth z, at horizontal
  distance r, from concentrated load Q
• simplification eq. 6-5
• Stress influence factors Iw, and Ib Fig. 6-3
• Example 6-1 and 6-2

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Vertical Pressure - uniform load

• Approximate Method
• Area of stress increases with depth with a 21
  slope as shown in Fig. 6-5.
• Eq. 6-6
• Example 6-3

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Vertical Pressure - uniform load

• Elastic Theory
• Uniform Load on a Circular Area
• Table 6-1
• Example 6-5
• Total vertical pressure vertical stress
  increment(q) overburden pressure(po)
• Uniform Load on a Rectangular Area
• Table 6-2
• Example 6-7

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Vertical stress increment at multiple locations

• Figure 6-9
• Example 6-8 and 6-10

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Homework for Friday

• Chapter 5.
• 5-1, 5-5, 5-6, 5-7 and 5-8
• Chapter 6
• 6-1, 6-2, 6-3, 6-8 and 6-10

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• Problem
• 6-5
• 6-7
• 6-11