Introduction to Geotechnical Engineering ground N. Sivakugan Duration: 11 min 56 s

Typical Geotechnical Project Geo-Laboratory ~ for testing Design Office ~ for design & analysis soil properties design details soil samples construction site

Geotechnical Applications

Shallow Foundations ~ for transferring building loads to underlying ground ~ mostly for firm soils or light loads bed rock firm ground

Shallow Foundations

Deep Foundations ~ for transferring building loads to underlying ground ~ mostly for weak soils or heavy loads P I L E bed rock weak soil

Deep Foundations Driven timber piles, Pacific Highway

Retaining Walls ~ for retaining soils from spreading laterally Road Train retaining wall

Earth Dams ~ for impounding water soil reservoir clay core shell

Concrete Dams reservoir soil concrete dam

Concrete Dams Three Gorges Dam, Hong Kong

Concrete Dams

Earthworks ~ preparing the ground prior to construction Roadwork, Pacific Highway

Construction hazard ~ an unwelcome visitor at an earthwork site. What does it have to do with Geo?#! A dead Anaconda python (courtesy: J. Brunskill)

Geofabrics ~ used for reinforcement, separation, filtration and drainage in roads, retaining walls, embankments… Geofabrics used on Pacific Highway

Reinforced Earth Walls ~ using geofabrics to strengthen the soil

Soil Nailing ~ steel rods placed into holes drilled into the walls and grouted

Sheet Piles ~ sheets of interlockingsteel or timber driven into the ground, forming a continuous sheet ship warehouse sheet pile

Sheet Piles ~ resist lateral earth pressures ~ used in excavations, waterfront structures, ..

Sheet Piles ~ used in temporary works

Sheet Piles ~ interlocking sections

Cofferdam ~ sheet pile walls enclosing an area, to prevent water seeping in Cofferdams are often used in temporary works, to enclose the construction area within a continuous sheet pile wall around and protect it from water entering from outside.

Landslides

Shoring propping and supporting the exposed walls to resist lateral earth pressures

Tunneling

Blasting For ore recovery in mines

Ground Improvement Impact Roller to Compact the Ground

Ground Improvement Sheepsfoot Roller to Compact Clay Soils

Ground Improvement Smooth-wheeled Roller

Ground Improvement Big weights dropped from 25 m, compacting the ground. Craters formed in compaction

Environmental Geomechanics Waste Disposal in Landfills

Instrumentation ~ to monitor the performances of earth and earth supported structures ~ to measure loads, pressures, deformations, strains,… Finally, proof of the pudding is in the eating. Very often we monitor the performances of foundations, tie backs, embankments etc. for a long time after construction, to verify that it is performing to our expectations. Geotechnical engineering involves lots of uncertainty in the soil properties used in the designs and the theories. Instrumentation is a popular method to verify the theories, assumptions, construction methods etc.

Soil Testing Cone Penetration Test Truck – Lavarach Barracks, Townsville

Soil Testing Vane Shear Test Standard Penetration Test More Field Tests

Soil Testing Triaxial Test on Soil Sample in Laboratory

Soil Testing Variety of Field Testing Devices

Soil Testing Purdue University, USA Being Pushed around by my Supervisors

Typical Safety Factors Type of Design Safety Factor Probability of Failure Earthworks 1.3-1.5 1/500 Retaining structures 1.5-2.0 1/1500 Foundations 2.0-3.0 1/5000

Some unsung heroes of Civil Engineering… foundations soil exploration tunneling All structures need proper foundations. To design good foundations, it is essential to know the geotechnical characteristics of the underlying ground. The only way to know them is to test the soil. … buried right under your feet.

Great Contributors to the Developments in Geotechnical Engineering Hall of Fame Great Contributors to the Developments in Geotechnical Engineering

Siva’s teacher in USA – deserves gold frame WJM Rankine 1820-1872 A.Casagrande 1902-1981 C.A.Coulomb 1736-1806 Karl Terzaghi 1883-1963 Siva’s teacher in USA – deserves gold frame L. Bjerrum 1918-1973 A.W.Skempton 1914- G.F.Sowers 1921-1996 G.A. Leonards 1921-1997

Geotechnical Engineering Landmarks Challenges Geotechnical Engineering Landmarks

Leaning Tower of Pisa Our blunders become monuments!

Hoover Dam, USA Tallest (221 m) concrete dam

Petronas Tower, Malaysia Tallest building in the world

Monuments and….

CS2005: Geo-Engineering I

Geo-engineering at JCU CS2005 Geo-engineering I CS3002 Geo-engineering I CS4001 Geo-engineering I Postgrad MEngSc/PhD

Practicals ~ five practical sessions ~ closed footwear must be worn in the lab

Laboratory Staff Neville Hines & Rudd Rankine

Quizzes How? about 4-6, 50 minutes each open book Why? to reinforce main points provides a wake up call form of assessment

Past CS2005 Grades 1996 1997 1998 1999 2000 2001 2002 HD 5 1 3 ? D 4 2 9 6 C 15 12 7 P 8 10 P- N 14 13 X Total 54 33 35 39 42

Some Suggestions Attend the lectures. It takes longer to understand from the lecture notes Develop a good feel for the subject. It is practical, interesting and makes lot of sense.

Some Suggestions Work in groups.

Some Suggestions Thou shall not wait till the last minute.

Exams My mama always said, “Exam is like a box of chocolates; you never know what you are gonna get”