Matakuliah
Tahun
Versi
: S2094 / Rekayasa Pondasi
: 2005
: 1.1
Pertemuan 09
Penurunan Pondasi Dangkal
Shallow Foundations - Settlement
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
Design Requirements
Overview of Settlement Analysis Methods
Induced Stresses Beneath Shallow Foundations
Settlement Analysis Based on Laboratory Tests
Settlement Spreadsheet
Settlement in Analysis Based on In-situ Tests
Settlement in Stratified Soils
Differential Settlement
Rate of Settlement
Accuracy of Settlement Predictions
Design Requirements
 Total Settlement ()
  a
 Differential Settlement(D)
 D   Da
 versus D
(b) Palacio de las Bellas
Artes, Mexico City
(a)Leaning Tower, Pisa
Overview; Settlement Analysis
 Plate Load Tests
 Based on Laboratory Test Data
 Based on In-situ Tests
Plate Load Tests
Methods for Calculating Induced
Stresses
 z  I (q   zD )




Boussinesq’s Method
Westergaard’s Method
Simplified Method
60o Approximation ( CE 3321 textbook)
Boussinesq’s Method
Boussinesq’s Method
Boussinesq’s Method
Pressure Bulbs
Newmark’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)
 
 
 
1
 z  1  
   B
  1  
   2 z f

1.50




2
 
 
 
 



 (q   zD )




Simplified Methods (Approximate)
•
For square foundations (Poulos and Davis,
1974)
 
 
 
1
 z  1  
   B
  1  
   2 z f

1.76




2
 
 
 
 



 (q   zD )




Simplified Methods (Approximate)
•
For continuous foundations (Poulos and Davis,
1974)
 
 
 
1
 z  1  
   B
  1  
   2 z f





2
 
 
 
 
2.60



 ( q   zD )




Simplified Methods (Approximate)
•
For rectangular foundations (Poulos and
Davis, 1974)
 
 
 
 z  1  
   B
  1  
   2 z f




1

1.38 0.62 B / L








2.60 0.84 B / L



 (q   zD )




Approximate Methods
1:2 method (60° approximation)
Computer Software FTGSETT (settlement.xls)