Embed Size (px)
DESCRIPTION
It is not common for one to enjoy rereading somethingthat he wrote a decade previously. Times change, styleschange, attitudes change, and most of all people grow, bothintellectually and emotionally. It is therefore with gratificationand some little surprise that I was able to reread Principlesof Personal Defense at the request of the publishers,and to discover that I felt no need to change anything ofimportance. It stands as it stood, and insofar as it spoke thetruth ten years ago, it speaks it still.The booklet is essentially a digest of a presentation Ideveloped while working in Central America before theCommunist takeover there. This part of the world has alwaysbeen turbulent, and the need for individual selfdefensehas remained fairly constant ever since the departureof the Spanish in the early part of the nineteenth century.Individual conduct in lethal confrontation is not,however, something that is confined to any one locale orera, and if there are principles guiding its conduct-and Ibelieve there are-those principles do not change accordingto geography, history, or sociological whim. If a principleexists it must be immutable, for that is what a principle isvll
Citation preview
1/20/2013
1
Instructor: JM Albaine
Introduction & Overview Lecture
SPRING 2013
Ground Rules, Syllabus etc.
1/20/2013
2
1/20/2013
3
1/20/2013
4
1/20/2013
5
"As a designer, realize that what your professors taught you is onlyabout 1%(maybe 0.9% for a B.S. and 1.1% for a Ph.D.) of whatyou really need to know.
The good news is that you have about 40 years to learn the rest"
INTRODUCTION TO GEOTECHNICAL ENGINNERING
1/20/2013
6
1/20/2013
7
1/20/2013
8
1/20/2013
9
1/20/2013
10
Process of solving problems that involve safe and economical transfer of structural loads to the ground.
Interface or transition elements between (super) structure and ground.
Transfer/transmit loads from structure to underlying material (soil/rock).
1/20/2013
11
Geotechnical EngineeringSoil MechanicsRock MechanicsEngineering Geology
Foundation DesignSlope Stability AnalysisRetaining Structure Design
Landfill DesignWaste ContainmentSubsurface Remediation and Cleanup
Basic Sciences
Traditional Applications
Geo-Environmental Applications
Types of Foundations
• Shallow Foundations– Footings– Rafts
• Deep Foundations– Piles– Caissons
Built Near Ground Surface
(if near surface ground is competent)
Penetrate Deep into Ground
(if near surface is notcompetent)
1/20/2013
12
Shallow Foundations
• Combined FootingIsolated Footing
Shallow Foundations
• Strip FootingStrap Footing
1/20/2013
13
Shallow Foundations
Raft/Mat Foundation
Deep Foundations
• Piles
Single Pile Pile Group Piled Raft/Mat
1/20/2013
14
Shallow and Deep Foundations
Column
Single Pile
Pile Group
Pile Cap
Building
Beam
Ground Surfac
Sequence of Activities in a Foundation Problem
Global Scale1. Owner/Developer Acquires Site2. Owner Hires Architects/Consultants3. Consultant Hires Specialty
Contractors/Consultants4. Planning, Design, Construction, Testing5. Monitoring/Performance Evaluation
1/20/2013
15
Scale of Foundation Engineering
Problem Identification
(say, a Hotel or a Football Stadium)
Information Collection• Loads• Ground Conditions
Information ProcessingSelection of Foundation Type(s), Design Method(s), Construction Method(s) etc.
Execution• Design
• Construction
Evaluation• Load Test on
Foundation(s)• Performance
Monitoring
Corrective Measure
(if required)Foundation Retrofitting
Foundation Decisions
• Choice of Foundation Type(s)• Choice of Design Parameters and Design
Method(s)• Choice of Method(s) of Construction and
Testing• Choice of Methods of Monitoring
1/20/2013
16
Factors Governing Selection of Foundation Type
• Feasibility• E.g., Large load or Soft Soil typically requires Deep Foundations
• Constructability• E.g., Driven Piles cannot be used for a Site Filled with Boulder
• Availability of Construction Equipments• E.g., If Site is Perfect for Driven Piles but Pile Driving Equipment is not
Locally Available, then Bored Piles have to be Constructed
• Project Specific Factors• E.g., Tight Deadlines may preclude certain Foundation Types; If
Lowering of Water Table is not permitted then Shallow Foundations have to be avoided
• Environmental Factors• E.g., Pile Driving may not be possible if Adjacent Structures are
Damage-prone
Foundation Design ApproachesWorking/Allowable Stress Design (WSD/ASD)
• Factor of Safety Design• Calculate Ultimate Foundation Capacity (or Resistance)
Cultimate• Estimate Working Load Lworking• Decide on required Factor of Safety F• Design such that Cultimate/F = Callowable ≥ Lworking
Limit State Design (LSD)Load and Resistance Factor Design (one type of LSD)
Reliability Based Design (RBD)• Probabilistic Estimation of Foundation Capacity and
Applied Loads – Accounts for “Uncertainty”• Probabilistic Estimation of Safety Against Potential
“Failures”
1/20/2013
17
Limit States• Serviceability Limit States – set of unacceptable
conditions related to Performance, e.g., excessive settlement or tilt• Excessive Settlement of a Building Leading to
Malfunctioning of Service Lines• Excessive Uneven Settlement Leading to Building
Cracks
• Ultimate Limit States – set of unacceptable conditions related to Safety/Danger, e.g., collapse• Bearing Capacity Failure leading to Plunging of
Foundation• Excessive Settlement of Building leading to Structural
Collapse
Trends in Geotechnical Design
• Traditional Approach – Working Stress Design (WSD)
• Current Trend – Load and Resistance Factor Design (LRFD)
Load and Resistance Factor Design• Special Type of Limit State Design (LSD) • Borrows Concepts from Reliability Based Design (RBD)
1/20/2013
18
Geotechnical Engineering is a Science but its practice an Art
Structural Engineering is the art and science of molding materials we donot fully understand into shapes we cannot precisely analyze to resistforces we cannot accurately predict, all in such a way that the societyat large is given no reason to suspect the extent of our ignorance.
Text: Pg. 7
