Advanced Soil Mechanics

Instructor(s): Prof. Charles Ladd; Dr. Lucy C. Jen

MIT Course Number: 1.361 / 1.032 / 1.366

As Taught In: Fall 2004

Level: Undergraduate / Graduate

Course Description

This class presents the application of principles of soil mechanics. It considers the following topics: the origin and nature of soils; soil classification; the effective stress principle; hydraulic conductivity and seepage; stress-strain-strength behavior of cohesionless and cohesive soils and application to lateral earth stresses; bearing capacity and slope stability; consolidation theory and settlement analysis; and laboratory and field methods for evaluation of soil properties in design practice.

Syllabus

Course Meeting Times

Lectures: 2 sessions / week, 1.5 hours / session

Definition

Technology that deals with soil (and rock) as an engineering material in civil engineering projects.

Examples of Application Areas

  1. Foundations
    • “shallow” e.g., spread footings for buildings
    • “deep” e.g., piles for offshore platform
  2. Earth Structures
    • Compacted earth fill for dam
    • Landfill for waste storage
  3. Slopes and Excavations
    • Cut slopes for highway
    • Excavation for subway
  4. Retaining Structures
    • Slurry wall with tieback anchors
    • Gravity retaining wall
  5. Remediation of Contaminated Soil and Groundwater

Types of Input Required to Solve Above Problems (for Soil)

  1. Geology and Exploration: General nature and extent of soils involved
  2. Soil Mechanics: Evaluation of Engineering Properties of soils and Theoretical Analyses to predict behavior of “structure”
  3. Feasibility: Economics, environmental, legal, practical
  4. Experience: Regarding what has happened in the past – successes and failures
  5. Field Evaluation: Measurements of actual performance to evaluate and possibly alter design during construction
  6. Engineering Judgment: Combined with above – final solution (increasing use of reliability analyses to “formalize” process)

What Makes Soil Mechanics Interesting and Challenging (CCL’s opinion)

Soil amongst most variable and difficult of all materials to understand and model

  1. Complex stress-strain (non-linear, irreversible)
  2. Properties highly variable function of soil types and stress history
  3. Properties change with time, stress, environment, …
  4. Every site has different soil conditions – new challenge
  5. Soil “hidden” underground and data on small fraction of deposit

Emphasis on testing (in field and in lab) plus field monitoring

Outline

PART # TOPICS
I Introduction

Geotechnical / Geoenvironmental Engineering

Conduct of Subject

II Nature of Soil

Soil Composition, Index Properties, Soil Classification

Soil Structure: Clay-Water Forces, Interparticle Forces, Fabric

Environmental Factors

III Dry Soil (Cohesionless)

Mohr Circle, Stress Paths, Elastic Stress Distribution

Stress-Strain and Strength Behavior of Sand

Rankine Earth Pressures, Infinite Slopes, Retaining Walls

Bearing Capacity of Sands (Theory and Practice)

Settlement of Sands

IV Saturated Soil (No or Steady State Flow)

Effective Stress Principle, Capillarity, Soil Suction

One- and Two-Dimensional Flow

Coefficient of Permeability (Theory and Practice)

Stress-Strain and Strength Behavior of Clays
1-D Behavior (Theory and Practice)
Drained Shear Behavior, Strength Principles

Lateral Earth Pressures

Slope Stability and Bearing Capacity

V Saturated Soil (Transient Flow)

Pore Pressure Parameters, Undrained Shear Behavior of Clays, and Strength Principles

Consolidation of Cohesive Soils
Terzaghi Theory
LC Compression
Special Topics

Evaluation of Stability (Loading vs. Unloading and Undrained vs. Drained Conditions)

Estimation of Undrained Strength for Design

Settlement Analyses for 2, 3-D Loadings

Calendar

LEC # TOPICS DEMONSTRATIONS HOMEWORKS HANDOUTS
1 Introduction
II-1 (7)
Clay Model
Sand and Clay Samples
Homework #1 out Registration Form, Introduction, TOC Notes, II-1 (Comp.)
II-2 (Structure)
2 II-1 (13)
II-2 (3-4)
AL Device and Hydrometer Mini problem out Part II Mini Problem
3 II-2 (11-12) BBC-Electrophoresis
BBC-Ovendried plus Soaked, X-Rays
III-1 (Stresses)
4 II-2 (17+/-) BBC-Add Salt to Dispersed Clay
5 II-2 (19)
III-1 (6)
III-2 (1)
Oed, DS and TX Mini problem due III-2 (Stress-Strain-Strength)
6 III-2 (8) Homework #2 out
Homework #1 due
7 III-2 (18) III-3 (Lateral Earth Pressure)
8 III-2 (20)
Part II MP – 5-10 minutes Discussion
III-3 (5)
Homework #3 out
Homework #2 due
III-4 (Bearing Capacity)
9 III-3 (9)
III-4 (4)
10 III-4 (18) Homework #4 out
Homework #3 due
III-5 (Settlement)
11 III-4 (19)
III-5 (14)
IV-1 (s’ and Capillarity), Reading Assignment #2
12 III-5 (16)
IV-1 (6)
Homework #5 out
Homework #4 due
IV-2 (1-D Flow)
IV-2A (2-D Flow)
13 IV-2 (5)
IV-2A (1-)
IV-3 (Permeability)
14 IV-2A (3)
IV-3 (3)
IV-4 (Clay behavior)
’03 MTE Exam and Solution
15 IV-3 (4)
IV-4 (3 w/Tide Problem)
(MTE Review Session) Homework #6 out
Homework #5 due
16 IV-4 (10+) (Midterm Exam) IV-5 (Lateral Earth Pressure)
17 IV-4 (12)
IV-5 (5-)
Homework #8 out
Homework #6 due
IV-6 (Slope Stability)
IV-7 (Bearing Capacity)
18 IV-5
IV-6
IV-7 (3)
Homework #9 out
19 Return MTE and Solution plus Discussion
V-1 (6-)
Homework #8 due
20 V-1 (12) Homework #10 out V-2 (Consolidation)
21 V-1 (Review UU + 16)
V-2 (4)
Homework #9 due V-3 (Stability)
22 V-2 (9)
V-3 (6)
Homework #11 out
Homework #10 due
23 V-3 (11)
V-4 (7)
PP, TV  ’03 FE and Solution
24 V-4 (25) Homework #12 out
Homework #11 due
V-5 (Settlement)
25 V-5 (8)

Readings

Amazon logo Lambe, T. William, and Robert V. Whitman. Soil Mechanics. New York: Wiley, 1969. ISBN: 0471511927.

Reading Assignment Schedule No. 1

Read: Read mainly for general background and interest.

Study: Know all definitions, concepts, derivations of formulas, etc. This information will be covered in class and in Homework Problems and will form the main basis for materials on the exams.

CHAPTER # READ OR STUDY COMPLETED BY LEC #
1, 2 Read 2
3 Study 2
4, 5, 6, 7 Read 3
8 Study 4
9, 10, 11, 12 Study 5
13 Study 6
14 Study 8

Lecture Notes

The following set of lecture notes cover every major topic discussed in class.

Part II-1 Soil Composition, Index Properties and Soil Classification (PDF – 1.6 MB)

Part II-2 Soil Structure and Environmental Effects (PDF)

Part III-1 Dry Soil: Stresses (PDF)

Part III-2 Stress-Strain-Strength Properties (PDF – 1.0 MB)

Part III-3 Lateral Earth Pressures and Retaining Walls (PDF)

Part III-4 Shallow Foundations on Sand: Bearing Capacity (PDF – 3.0 MB)

Part IV-1 Effective Stress Principle and Capillarity (PDF)

Part IV-2 One-Dimensional Flow (PDF)

Part IV-2A Two-Dimensional Flow (PDF)

Part IV-3 Coefficient of Permeability (PDF 1 of 2) (PDF 2 of 2 – 2.0 MB)

Part IV-4 Stress-Strain-Strength Behavior of Saturated Clays (PDF – 2.4 MB)

Part IV-5 Lateral Earth Pressures (PDF)

Part IV-6 Slope Stability (PDF)

Part IV-7 Bearing Capacity (PDF)

Part V-1 Introduction, Pore Pressure Parameters and Undrained Shear (PDF)

Part V-2 Consolidation and Secondary Compression (PDF)

Part V-3 Stability Evaluation: Cohesive Soils (PDF)

Part V-4 Estimation of Design su in Practice (PDF – 2.0 MB)

Part V-5 Settlement Analyses (PDF – 3.0 MB)

Study Materials

MEASURABLE QUANTITIES COMMON AND SI UNITS
Length in x 25.40 = mm
mil x 10-3 = in
ft x 0.3048 = m
yd x 3 = ft
Angstrom x 10-4 = µm
Angstrom x 0.1 = nm
Area hectare x 104 =m2
acre x 43560 = ft2
Volume ft3  x 1728 = in.3
ft3  x  0.02832 = m3
yd3 x 0.7646 = m3
gal x 3.785 = liter = 10-3m3
ounce (U.S. fluid) x 29.57 = cm3
Mass lb x 0.4536 = kg
U.S. ton x 907.2 = kg
Force [N = (kg) (g = 9.807 m2/s)] kip x 1000 = lbf
bf  x 4.448 = N
U.S. ton x 2000 = lbf
kgf x 9.81 = N
metric ton x 9.81 = kN
dyne x 10-5 = N
Unit Weight γw = 1.00 TCM =g/cm3
γw = 62.4 pcf
γw = 9.81 kN/m3
pcf x 0.1571 = kN/m3
Energy joule (J) = N . m
ft . lbf x 1.356 = J
cal x 4.187 = J
erg = dyne . cm
erg x 10-7 = J
Pressure (Common) atm = 760 mm of Hg
atm x 1.0332 = kgf/cm2
psi x 144 = psf
ksf x 1000 = psf
TSF x 2000 = psf
kgf/cm2 x 2048 = psf
kgf/cm2 x 10 = TSM
TSM x 204.8 = psf
dyne/cm2 x 10-6 = bar
Pressure (Pa = N/m2) bar = 100 kPa
atm x 101.3 = kPa
psi x 6.895 = kPa
psf x 47.88 = Pa
ksf x 47.88 = kPa
TSF x 95.76 = kPa
kgf/cm2 x 98.07 = kPa; x 2.048 = ksf
TSM x 9.807 = kPa
dyne/cm2 x 0.1 = Pa
Coefficient of Permeability cm/s x 864 = m/day
cm/s x 2835 = ft/day
ft/day x 0.3048 = m/day
Coefficient of Consolidation cm2/s x 8.64 = m2/day
cm2/s x 93.0 = ft2/day
in2/min x 0.929 = m2/day
in2/min x 10  = ft2/day
ft2/day x 0.0929 = m2/day
Power watt = J/s
Temperature oC/100 = (oF – 32)/180

Download Course Materials

This package contains the same content as the online version of the course, except for any audio/video materials and other interactive file types.

Download here.

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