Geotechnical Engineering - rezasalehi.com · Geotechnical Engineering CE 4348 Lecture 1: ... Solved...
Transcript of Geotechnical Engineering - rezasalehi.com · Geotechnical Engineering CE 4348 Lecture 1: ... Solved...
Geotechnical Engineering
CE 4348
Lecture 1: Introduction
Instructor: Reza Ashtiani, Ph.D.
Fall 2015
Physical Science Bldg., Room 314
Lecture Sessions : MW 12:30-1:20 pm
Laboratory Sessions: MW 1:30-4:30 pm
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Civil and Mechanical Engineering (2012)
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Civil and Mechanical Engineering (2012)
Course Structure
Textbook: An Introduction to Geotechnical Engineering, 2nd Edition by Holtz, Kovacs and Sheahan, Publisher: Prentice Hall, 2011. Class Website: www.rezasalehi.com/CE-4348 Site Password: students Grading:
1. Final Comprehensive Exam (300 points) 2. Two Mid-Term Exams (300 points) 3. Laboratory Reports (200 points) 4. Homework Assignments (200 Points) 5. Critical Assessment (attendance and involvement in class
discussions) (50 points) __________________________________________
Total: 1050 Points
CE
43
48
-Geo
tech
nic
al
Eng
inee
rin
g
Ph
ysic
al P
rop
erti
es o
f So
ils
Weight-Volume Relations
Phase Diagrams
Soil Texture Atterberg Limits
Soil Plasticity
Shrink-Swell Potential Aggregate Geometry
Soil Classification USCS Method
AASHTO Method
Soil Compaction
Mec
ha
nic
al A
na
lysi
s o
f So
ils
Effective Stress Pore Water Pressure
Geostatic Stresses Effective Stress
Calculations
Flow of Water in Soils
1D-Flow Theory Darcy’s Law
Soil Permeability
Constant Head Permeability Test
Falling Head Permeability test
2D-Flow Theory Flow Nets
External Stresses Boussinesq Theory Newmark Method
Westergaard Theory
Shear Strength of Soils
Mohr-Coulomb Theory
Direct Shear Test
Triaxial Tests
Consolidated Drained (CD)
Consolidated Undrained (CU)
Unconsolidated Undrained (UU)
Mohr Circle
Settlement Analysis
Immediate Settlement
Primary Consolidation
Secondary Compression
Time Rate of Settlement
Item Description Quantity
Lecture Topics 9
Lecture Segments 16
PowerPoint Slides 651
Solved Examples in the Class 34
Laboratory Tests 7
Laboratory Reports 5
Homework Assignments 6
Homework Problems 45
Exams 3
CE4348 Score Card Previous Semester
• Provide students with physical,
mechanical, and mathematical tools
and concepts for the understanding
of engineering behavior of soils and
introduction to engineering design of
geotechnical systems.
Course Objective
Significance
• All the civil engineering structures,
weather built on earth or any other
continuum, is greatly influenced by the
foundation.
• The performance and safety of civil
engineering structures are primarily
dependent on proper characterization of
soil-structure interaction.
• According to a geologist, Soil is the material
in the relative thin surface zone within which
roots occur, and all the rest of the crust is
grouped under the term ROCK irrespective of
its hardness.
• According to a civil engineer, Soil is the un-
aggregated or un-cemented deposits of
mineral and/or organic particles or fragments
covering large portion of the earth's crust.
Definitions of Soils
• Soil mechanics is a discipline that applies the principles of engineering mechanics to soils to predict the mechanical behavior of granular materials.
• Geotechnical Engineering is the branch of civil engineering that deals with soil, rock, and underground water, and their relation to the design, construction and operation of engineering projects.
Definitions
Geotechnical engineering is a branch of civil engineering, whereas engineering
geology is a branch of geology. These two disciplines are closely related, and
the discipline combining the two is sometimes called geotechnics. Note: This
illustration is not a complete listing of the branches of either discipline.
• Soil Mechanics:
– Geological Characteristics of Soil
– Physical Soil Parameters
– Seepage though Soils
– Stress and Strain in Soils
– Effective Stresses
– Deformation in Soils
– Shear Stress in Soils
Buildings—the Sears Tower in Chicago is one of the tallest buildings
in the world (1450 ft.,110 story). It needs massive foundations to
transmit the structural loads into the ground. The design of these
foundations depends on the nature of the underlying soils.
Geotechnical engineers are responsible for assessing these soil
conditions and developing suitable foundation designs.
Bridges—the foundation for the south pier of the Golden Gate Bridge in San
Francisco had to be built in the open sea. It extends down to bedrock, some 30 m
(100 ft) below the water level and 12 m (40 ft) below the channel bottom. This was
especially difficult to build because of the tremendous tidal currents at this site.
Dams—Oroville Dam in California is one of the largest earth dams in the world. It
is made of 61,000,000 m3 (80,000,000 yd3) of compacted soil. The design and
construction of such dams require extensive geotechnical engineering experties.
Tunnels—the Ted Williams Tunnel is part of the Central Artery Project in Boston. This
prefabricated tunnel section was floated to the job site, and then sunk into a prepared
trench in the bottom of the bay. Its integrity depends on proper support from the
underlying soils.
The leaning tower of Pisa. (Adapted from
Terzaghi 1934a.)
Slope failure
This house was built near the top of a slope and had a beautiful view of the
Pacific Ocean. Unfortunately, a landslide occurred during a wet winter,
undermining the house and causing part of its floor to fall away.
Teton Dam in Idaho failed in 1976, only a few months after the
embankment had been completed and the reservoir began to be filled.
This failure killed 14 people and caused about $400 million of property
damage. (Picture Courtesy of the Bureau of Reclamation)
The 1964 Niigata Earthquake in Japan caused extensive liquefaction in this port city.
These apartment buildings rotated when the underlying soils liquefied. (Courtesy of
Earthquake Engineering Research Center Library, Berkeley, California.)
The approach fill to this highway bridge has settled because the underlying soils are
soft clays and silts. However, the bridge has not settled because it is supported on
piles. Although this “failure” is not as dramatic as the others, it is a source of additional
maintenance costs, and can be a safety hazard to motorists and pedestrians.
Basic Geotechnical Engineering Design Projects
– Bearing Capacity: Shallow and Deep
Foundation
– Earth Pressure - Retaining Walls
– Slope Stability
– Geosynthetic Design
• Geo-Environmental Engineering
• Design is the process whereby a problem
is solved for a certain conditions and
constrains, and meeting specified
performance criteria.
• This definition applies to any civil and
geological engineering system.
Geotechnical Design
Foundation Systems
• Designing of Shallow Foundation Systems – Differential Settlements
• “Canada's Leaning Tower or the "Kissing Silos”
(from Sharma 2003)
Foundation Systems
Deep Foundation Systems: Driven Piles
Foundation Systems
Deep Foundation Systems: Drilled Shafts
Earth Pressure and Retaining Walls
• Designing of retaining walls
Reinforced Earth
(from BECC Engineering 2001)
Earth Pressure and Retaining Walls
• Reinforced Earth Walls
(The Reinforced Wall Company 2003)
Earth Pressure and Retaining Walls
• Sheet Piles
(Boulanger and Duncan 2003)
Retaining Structure Systems
• Gabions
(Gaviones LEMAC (2003)
Retaining Structure Systems
• Tie-backs
(Boulanger and Duncan 2003)
Retaining Structure Systems
• Excavation Support Systems
(Boulanger and Duncan 2003)
Geosynthetics
• Geosynthetic stabilized walls
(Environmental Science & Engineering 2007) (kshitija.wordpress.com 2007)
Soil Improvement
• Stone Columns
(Boulanger and Duncan 2003)
Soil Improvement
• Jet Grouting
(Boulanger and Duncan 2003)
Soil Improvement
• Compaction Grouting
(Boulanger and Duncan 2003)
Soil Improvement
• Chemical Injection
(Boulanger and Duncan 2003)
Geo-Environmental Engineering
• Characterization and remediation of Geo-
environmental hazards
(from Willmer 2001)
Municipal Solid Waste (MSW) Landfill
(from Norwegian Geotechnical Institute 2001)