Introduction to Geotechnical Engineering ground N. Sivakugan SIVA Duration: 13 mins 1 Typical Geotechnical Project Geo-Laboratory ~ for testing SIVA soil properties Copyright 2001 construction site Design Office ~ for design & analysis 2 Shallow Foundations ~ for transferring building loads to underlying ground ~ mostly for firm soils or light loads firm ground SIVA Copyright 2001 bed rock 4 Shallow Foundations SIVA Copyright 2001 Deep Foundations ~ for transferring building loads to underlying ground ~ mostly for weak soils or heavy loads P I L E weak soil bed rock SIVA Copyright 2001 6 Deep Foundations Driven timber piles, Pacific Highway SIVA Copyright 2001 7 Pier Foundations for Bridges Millau Viaduct in France (2005) Cable-stayed bridge Supported on 7 piers, 342 m apart Longest pier (336) in the world A separate slideshow on the construction is in the bottom drawer SIVA Copyright 2001 8 Pier Foundations for Bridges Millau Viaduct in France (2005) SIVA Copyright 2001 9 Retaining Walls ~ for retaining soils from spreading laterally retaining wall Road Train 10 SIVA Copyright 2001 Earth Dams ~ for impounding water reservoir clay core shell soil 11 SIVA Copyright 2001 Concrete Dams reservoir concrete dam soil 12 SIVA Copyright 2001 Concrete Dams Three Gorges Dam, Hong Kong SIVA Copyright 2001 13 Concrete Dams 14 SIVA Copyright 2001 Earthworks ~ preparing the ground prior to construction SIVA Copyright 2001 Roadwork, Pacific Highway 15 Construction hazard ~ an unwelcome visitor at an earthwork site. What does it have to do with Geo?#! A dead Anaconda python (courtesy: J. Brunskill) SIVA Copyright 2001 16 Geofabrics ~ used for reinforcement, separation, filtration and drainage in roads, retaining walls, embankments… SIVA Copyright 2001 Geofabrics used on Pacific Highway 17 Reinforced Earth Walls ~ using geofabrics to strengthen the soil 18 SIVA Copyright 2001 Tunneling MSE (Mechanically stabilised Earth) wall Chile (2006) – during my sabbatical leave SIVA Copyright 2001 19 Tunneling 20 SIVA Copyright 2001 Soil Nailing ~ steel rods placed into holes drilled into the walls and grouted 21 SIVA Copyright 2001 Retaining Walls Rock anchors to support the vertical walls SIVA Copyright 2001 22 Sheet Piles ~ sheets of interlockingsteel or timber driven into the ground, forming a continuous sheet warehouse ship sheet pile 23 SIVA Copyright 2001 Sheet Piles ~ resist lateral earth pressures ~ used in excavations, waterfront structures, .. 24 SIVA Copyright 2001 Sheet Piles ~ used in temporary works 25 SIVA Copyright 2001 Sheet Piles ~ interlocking sections 26 SIVA Copyright 2001 Cofferdam ~ sheet pile walls enclosing an area, to prevent water seeping in 27 SIVA Copyright 2001 Cofferdam ~ sheet pile walls enclosing an area, to prevent water seeping in 28 SIVA Copyright 2001 Landslides 29 SIVA Copyright 2001 Shoring propping and supporting the exposed walls to resist lateral earth pressures 30 SIVA Copyright 2001 Excavations Chile (2006) – during my sabbatical leave SIVA Copyright 2001 31 Mining 32 SIVA Copyright 2001 Blasting For ore recovery in mines 33 SIVA Copyright 2001 Earthquake Engineering Loma Preita Earthquake, San Francisco (1989) 34 SIVA Copyright 2001 Ground Improvement Impact Roller to Compact the Ground 35 SIVA Copyright 2001 Ground Improvement Sheepsfoot Roller to Compact Clay Soils 36 SIVA Copyright 2001 Ground Improvement Smooth-wheeled Roller 37 SIVA Copyright 2001 Ground Improvement Big weights dropped from 25 m, compacting the ground. Craters formed in compaction SIVA Copyright 2001 38 Environmental Geomechanics Waste Disposal in Landfills 39 SIVA Copyright 2001 Instrumentation ~ to monitor the performances of earth and earth supported structures ~ to measure loads, pressures, deformations, strains,… 40 SIVA Copyright 2001 Soil Testing SIVA Copyright 2001 Vane Shear Test Standard Penetration Test More Field Tests Soil Testing Triaxial Test on Soil Sample in Laboratory SIVA Copyright 2001 42 Soil Testing Variety of Field Testing Devices SIVA Copyright 2001 43 Soil Testing Purdue University, USA SIVA Copyright 2001 Being Pushed around by my Supervisors 44 Typical Safety Factors Type of Design Safety Factor Probability of Failure Earthworks 1.3-1.5 1/500 Retaining 1.5-2.0 structures Foundations 2.0-3.0 1/1500 1/5000 45 SIVA Copyright 2001 Some Civil Engineering marvels …. foundations soil exploration tunneling … buried right under your feet. SIVA Copyright 2001 46 Soil Testing Cone Penetration Test Truck – Lavarach Barracks, Townsville SIVA Copyright 2001 Dynamic Compaction JCU site visit to Townsville Port in 2003 49 SIVA Copyright 2001 Sheet pile at Woolcock St 50 SIVA Copyright 2001 Soil Nailing at Strand 51 SIVA Copyright 2001 JCU Dynamic cone penetration rig 52 SIVA Copyright 2001 JCU Dynamic cone penetration rig 53 SIVA Copyright 2001 Pile driving rig – Ross River Dam 54 SIVA Copyright 2001 Pile driving rig – Ross River Dam A pile group 55 SIVA Copyright 2001 Sea wall in Brisbane (2005) SIVA Copyright 2001 Courtesy: Coffey Geosciences Pty Ltd. 56 Great Contributors to the Developments in Geotechnical Engineering Karl Terzaghi 1883-1963 L. Bjerrum 1918-1973 C.A.Coulomb 1736-1806 A.W.Skempton 1914- WJM Rankine 1820-1872 Siva’s teacher in USA – deserves gold frame G.F.Sowers 1921-1996 A.Casagrande 1902-1981 G.A. Leonards 1921-1997 Purdue University (USA), 1986 Mini-Me SIVA Copyright 2001 Geotechnical Group: Postgrads & staff 59 Geotechnical Engineering Landmarks Leaning Tower of Pisa Our blunders become monuments! 61 SIVA Copyright 2001 Hoover Dam, USA SIVA Copyright 2001 Tallest (221 m) concrete dam 62 Petronas Tower, Malaysia Tallest building in the world 63 SIVA Copyright 2001 Monuments and…. 64 SIVA Copyright 2001 Geo-engineering at JCU CS2005 Introduction to Geotechnical Engineering CS3002 Soils & Foundations CS4001 Foundations & Rocks Postgrad MEngSc/PhD 66 SIVA Copyright 2001 Practicals ~ five practical sessions ~ closed footwear must be worn in the lab 67 SIVA Copyright 2001 Safety Rio de Janeiro We have pride in our high safety standards 68 SIVA Copyright 2001 Quizzes How? about 4-6, 50 minutes each open book Why? reinforce main points provide a wake up call form of assessment 69 SIVA Copyright 2001 Past CS2005 Grades 1996 1997 1998 1999 2000 2001 2002 HD 5 1 1 3 3 0 D 4 2 3 2 9 6 C 15 12 6 7 7 2 P 12 8 8 6 10 8 P- 6 0 2 4 1 5 N 12 10 12 14 9 13 X 0 0 3 3 3 1 33 35 39 42 35 Total 54 ? 70 SIVA Copyright 2001 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. 71 SIVA Copyright 2001 Some Suggestions Work in groups. 72 SIVA Copyright 2001 Some Suggestions Thou shall not wait till the last minute. 73 SIVA Copyright 2001 Exams My mama always said, “Exam is like a box of chocolates; you never know what you gonna get” 74 SIVA Copyright 2001 Recipe for Success I like soils… I like soils….I like soils…. 75 SIVA Copyright 2001