Chapter 3: Soil Mechanics

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Matakuliah S2094 / Rekayasa Pondasi Tahun
2005 Versi 1.1
Pertemuan 09Penurunan Pondasi Dangkal
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Shallow Foundations - Settlement

1. Design Requirements
2. Overview of Settlement Analysis Methods
3. Induced Stresses Beneath Shallow Foundations
4. Settlement Analysis Based on Laboratory Tests
5. Settlement Spreadsheet
6. Settlement in Analysis Based on In-situ Tests
7. Settlement in Stratified Soils
8. Differential Settlement
9. Rate of Settlement
10. Accuracy of Settlement Predictions

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Design Requirements

• Total Settlement (?)
• Differential Settlement(?D)

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?? versus ?D
(b) Palacio de las Bellas Artes, Mexico City
(a)Leaning Tower, Pisa
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Overview Settlement Analysis

• Plate Load Tests
• Based on Laboratory Test Data
• Based on In-situ Tests

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Plate Load Tests
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Methods for Calculating Induced Stresses

• Boussinesqs Method
• Westergaards Method
• Simplified Method
• 60o Approximation ( CE 3321 textbook)

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Boussinesqs Method
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Boussinesqs Method
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Boussinesqs Method
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Pressure BulbsNewmarks Solution of Boussinesq
Method
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Chart Solutions (Stress Bulbs)
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Chart Solutions (Stress Bulbs)
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Westergaards Method

• Provided solution for layered soils
• Point Loads

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Westergaards Method

• For distributed loads

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Simplified Methods (Approximate)

• For circular foundations (Poulos and Davis, 1974)

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Simplified Methods (Approximate)

• For square foundations (Poulos and Davis, 1974)

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Simplified Methods (Approximate)

• For continuous foundations (Poulos and Davis,
  1974)

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Simplified Methods (Approximate)

• For rectangular foundations (Poulos and Davis,
  1974)

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Approximate Methods

• 12 method (60 approximation)

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Computer Software FTGSETT (settlement.xls)