TOPIC 3: DESIGN AND ANALYSIS OF SHALLOW FOUNDATION
WEEK 6
• SETTLEMENT OF FOUNDATION ON SOIL
• REVIEW OF VERTICAL STRESS DISTRIBUTION
• FOUNDATION ON FILL
Learning Outcomes
Students should be able to:
• Determine the type of foundation on fill
(CO2-PO10)
SETTLEMENT OF SHALLOW FOUNDATION
Total settlement = Immediate Settlement + Consolidation Settlement
Immediate settlement (elastic) takes place during or immediately after the construction of the structure.
Consolidation Settlement occurs over a period of time. Consists of:
•Primary – squeezing of water from its void•Secondary – slippage and reorientation of soil particles
Calculation of Vertical Stress Increase
A) Stress Increase due to Concentrated Load
B) Stress due to Circularly Loaded Area
C) 2 : 1 Method
OTHER METHODS
• Newmarks Chart
• Fadums Chart
• Pressure Bulbs Chart
FOUNDATION ON FILL
Type of Fill
• Non engineered fill
• Engineered fill
• Reclaimed land
Foundation Selection
• May use raft for engineered fill – need to confirm before construction
• Ground improvement for reclaimed land – PVD, Vibro compaction, Dynamic ompaction, stone column etc
• Piling for non engineered fill.
TOPIC 3: DESIGN AND ANALYSIS OF SHALLOW FOUNDATION
WEEK 7
• Theoretical and Empirical Method for
Estimating Settlement.
• Total and Differential Settlement to Limit Damage
Learning Outcomes
Students should be able to:
• Able to estimate settlement (CO2-PO10)
• Able to determine angular distortion
(CO2-PO10)
• Able to discuss on tolerable settlement.
(CO2-PO10)
Elastic Settlement
Settlement of Rigid Foundation
Empirical Methods
Method based on Standard Penetration Test
Elastic Parameters of Soil
Correlation
Primary Consolidation Settlement
Primary Consolidation Settlement Calculations
Secondary Compression Index
Tolerable Settlement of Buildings
Parameters for Differential Settlement
Tolerable Settlement of Buildings
Guideline for Tolerable Settlement
Limiting Angular Distortion
Field Load Test
Test in Clay, qu(F) = qu(P)
Sand, qu(F) = qu(P) BF/BP
For a given qo
Terzaghi and Peck:
For sand, SF/SP = 4/ (1 +BP/BF)2
Clay, SF = SP. BF/BP
Calculate the average Stress Increase for the clay layer and the Consolidation Settlement