Untitled Flashcards Set

MODULE 1

INTRODUCTION OF GEOTECHNICAL ENGINEERING



INTRODUCTION

Geotechnical engineering is a branch of civil engineering that focuses on the behavior of earth materials and their application in construction and design. It encompasses several interconnected concepts, including soil, soil mechanics, and soil engineering, which collectively form the foundation of this discipline. The historical development of geotechnical engineering can be traced through key phases, beginning prior to the 18th century with rudimentary understanding and practices, progressing through the preclassical and classical periods where foundational theories were established in phases, and culminating in modern soil mechanics and advancements post-1927. This progression highlights the evolution of knowledge and methodologies that have shaped geotechnical engineering into a vital field for addressing complex challenges in infrastructure and environmental management.

The topics that will be covered in this module include:

  1. Soil, Soil Mechanics, Soil Engineering, Geotechnical Engineering

  2. History of Geotechnical Engineering: A Timeline

  1. Prior to 18th Century

  2. Preclassical Soil Mechanics

  3. Classical Soil Mechanics - Phase 1

  4. Classical Soil Mechanics - Phase 2

  5. Modern Soil Mechanics

  6. Geotechnical Engineering After 1927




Soil

  • uncemented aggregate of mineral grains and decayed organic matter with liquid and gas in the empty spaces between the solid particles.

  • where all the structures have been built

  • one of the necessary construction materials



Soil Mechanics

  • branch of science

  • study of the physical properties of soil and the behavior of soil masses subjected to various types of forces



Soil Engineering

  • application of the principles of soil mechanics to practical problems



Geotechnical Engineering

  • subdiscipline of civil engineering 

  • involves natural materials found close to the surface of the earth.

  • application of the principles of soil mechanics and rock mechanics to the design of foundations, retaining structures, and earth structures




GEOTECHNICAL ENGINEERING: A TIMELINE



  1. PRIOR TO THE 18TH CENTURY

  • Pyramid of Giza

  • based on a true experience, only in trial and error method

  • “what works and stays, it continues.”

  • Leaning Tower of Piza

  • one of the example of geotechnical engineering problem

  • had a weak clay-soil profile

  • it tilted up to 5.5° into maximum and excavated for it to be in 5° 



  1. PRECLASSICAL SOIL MECHANICS (1700 – 1776)

  • Concentrated on the studies relating to natural slope and unit weights of various types of soils as well as the semiempirical earth pressure theories

  • Natural Slopes

  • angle of repose

  • angle where the material become static



Henri Gautier

  • studied the natural slopes of soils when tipped in a heap for formulating the design procedures of retaining walls



Bernard Forest de Belidor

  • published a book proposing a theory for lateral earth pressure on retaining walls, following up Gautier’s original study

  • expanded the theory of Gautier



  1. CLASSICAL SOIL MECHANICS – PHASE I (1776 - 1856)



Charles Augustin Coulomb

  • used the principles of calculus for maxima and minima to determine the true position of the sliding surface in soil behind a retaining wall

  • used the friction and cohesion of soil



Jean Victor Poncelet 

  • extended Coulomb’s theory by providing a graphical method for determining the magnitude of the lateral earth pressure on vertical and inclined retaining walls with arbitrarily broken polygonal ground surfaces.

  • first person to use phi () as a symbol for soil frictional angle



William John Macquorn Rankin

  • provided a study on a notable theory on earth pressure and equilibrium of earth masses.

  • simplify the theory of Coulomb



  1. CLASSICAL SOIL MECHANICS – PHASE II (1856 - 1910)



Henri Philibert Gaspard Darcy

  • defined the term coefficient of permeability or hydraulic conductivity of soil.

  • Permeability

  • the ability of a material to allow fluids (liquids or gases) to pass through it



Joseph Valentin Boussinesq

  • developed the theory of stress distribution under load-bearing areas under ideal conditions

  • 4 Ideal Conditions

    • Load-bearing areas in a homogenous 

    • semi-infinite

    • elastic

    • isotropic medium



  • MODERN SOIL MECHANICS (1910 - 1927)

    • focus on clay



Albert Mauritz Atterberg

  • defined clay-sized fractions as the percentage by weight of particles smaller than 2 microns in size.

  • 3 Properties of Soil (Atterberg Limits)

    • Liquid Limits 

    • Plastic Limits

    • Shrinkage Limits



Arthur Langley Bell

  • developed relationships for lateral pressure and resistance in clay; bearing capacity of shallow foundations in clay



Wolmar Fellenius

  • developed the stability analysis of undrained saturated clay slopes 

  • Assumptions: critical surface of sliding = arc of a circle



Karl Terzaghi

  • developed the theory of consolidation for clays.

  • his theory became more significant after 1927



  • GEOTECHNICAL ENGINEERING AFTER 1927

    • International Society of Soil Mechanics and Foundation Engineering (ISSMFE) 

    • Soil Mechanics – A New Chapter in Engineering Science

    • American Society for Testing Materials (ASTM) – carries out the laboratory and field tests on soils, as for any other materials per standard method. 

    • The test methods for soils, rocks, and aggregates are bundled into the two volumes – 04.08 and 04.09



Karl Terzaghi 

  • Father of Modern Soil Mechanics 

  • Erdbaumechanik auf Bodenphysikalischer Grundlage by Karl Terzaghi (1925) - Earthwork Mechanics Based on Soil Physics