Matakuliah : S2094 / Rekayasa Pondasi

Tahun : 2005

Versi : 1.1

Pertemuan 09Penurunan Pondasi Dangkal

Shallow Foundations - Settlement

1. Design Requirements2. Overview of Settlement Analysis Methods3. Induced Stresses Beneath Shallow Foundations4. Settlement Analysis Based on Laboratory Tests5. Settlement Spreadsheet 6. Settlement in Analysis Based on In-situ Tests7. Settlement in Stratified Soils8. Differential Settlement9. Rate of Settlement10. Accuracy of Settlement Predictions

Design Requirements

Total Settlement ()

Differential Settlement(D)

a

DaD

versus D

(a)Leaning Tower, Pisa

(b) Palacio de las Bellas Artes, Mexico City

Overview; Settlement Analysis

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

Plate Load Tests

Methods for Calculating Induced Stresses

Boussinesq’s Method Westergaard’s Method Simplified Method 60o Approximation ( CE 3321 textbook)

)( zDz qI

Boussinesq’s Method

Boussinesq’s Method

Boussinesq’s Method

Pressure BulbsNewmark’s Solution of Boussinesq Method

Chart Solutions (Stress Bulbs)

Chart Solutions

(Stress Bulbs)

Westergaard’s Method

Provided solution for layered soils

Point Loads

Westergaard’s Method

• For distributed loads

Simplified Methods (Approximate)

• For circular foundations (Poulos and Davis, 1974)

)(

21

11

50.1

2 zD

f

z q

zB

Simplified Methods (Approximate)

• For square foundations (Poulos and Davis, 1974)

)(

21

11

76.1

2 zD

f

z q

zB

Simplified Methods (Approximate)

• For continuous foundations (Poulos and Davis, 1974)

)(

21

11

60.2

2 zD

f

z q

zB

Simplified Methods (Approximate)• For rectangular foundations (Poulos and

Davis, 1974)

)(

21

11

/84.060.2

/62.038.1 zD

LB

LB

f

z q

zB

Approximate Methods

1:2 method (60° approximation)

Computer Software FTGSETT (settlement.xls)