ECIV 330 Soil Mechanics Chapter1 - ECIV 330 Soil Mechanics...

ECIV 330 Soil Mechanics
Prof. Bill X. Yu
Spring, 2008

Chapter I Introduction to Soil Mechanics
Content
Introduction to soil mechanics
Typical problems faced by soil mechanics
A classic geotechnical problem
Requirement
A preliminary knowledge of the history of
soil mechanics

Introduction of Geotechnical Engineering
Soil
The term Soil has various meanings, depending upon
the general field in which it is being considered.
To a Pedologist ... Soil is the substance existing on the
earth's surface, which grows and develops plant life.
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.
To an Engineer .... uncemented aggregate of mineral
grains and decayed organic matter (solid particles) with
liquid and gas in the empty spaces between the solid
particles.

Soil Mechanics
According to Terzaghi (1948): "Soil Mechanics is
the application of laws of mechanics and
hydraulics to engineering problems dealing with
sediments and other unconsolidated
accumulations of solid particles produced by the
mechanical and chemical disintegration of rocks
regardless of whether or not they contain an
admixture of organic constituent."
Soil Mechanics is one of the youngest disciplines
of Civil Engineering involving the study of soil,
its behavior and application as an engineering
material.

Soils: Engineering Use and Properties to
Study
Engineering use
Support structural foundations
Construction materials
Properties
Origin, grain-size distribution, ability to
drain water, compressibility, shear
strength, load bearing capability

Geotechnical Engineering
Principle of Civil Engineering that involves
application of soil mechanics and rock mechanics
to the design of foundations, retaining
structures, and earth structures
Soil Mechanics (Soil Properties and Behavior)
Foundation Engineering (Deep & Shallow
Foundation)
Soil Dynamics (Dynamic Properties of Soils,
Earthquake Engineering, Machine Foundation)
Pavement Engineering (Flexible & Rigid
Pavement)
Rock Mechanics (Rock Stability and Tunneling)
Geosynthetics (Soil Improvement)

History of Soil Mechanics
Prior to 18
th
century
Experience with flood prevention
Irrigation
Building structures (pyramids, temples)
Î Necessity to address the behaviors of
soils in a more methodical manner

History of Geotechnical Engineering
Pre-classical (1700 to 1776 A.D)
Natural slope, unit weight of soils, earth
pressure theory
Visual description and unit weight as a
means to classify soils

History of Geotechnical Engineering