UNION COLLEGE

Civil Engineering Department

SOIL MECHANICS (CER-142)

Professor: Dr. Ashraf M. Ghaly, P.E.

Tel., email: 518-388-6515, ghalya@union.edu

COURSE OBJECTIVES:

The objective of this course is to introduce the civil engineering students to the behavior of soils under different loading conditions. It explores the natural characteristics, methods of classification, and testing of soils as an engineering material. The utilized methods of testing are those standardized by the American Society for Testing and Materials (ASTM). Basic topics covered within the framework of this course are soil exploration, composition, permeability, compaction, compressibility, shear strength and stresses within a soil mass, slope stability, and environmental geotechnology. Four class hours and three lab hours. Prerequisite: ESc 023. WAC: W1.

COURSE GRADE:

Assignments & Quizzes = 20%

Laboratory Reports = 20%

First Term Test = 15%

Second Term Test = 15%

Project GeoSlam = 5%

Final Examination = 25%

NOTES:

• Assigned homework are due as will be arranged. Late submission results in partial grade loss.
• Unannounced quizzes are probable to ensure students are keeping up with course work.
• Attendance of final exam is mandatory. If a student does not wish to solve given assignments, then this student may request that the assignments points be shifted to any or all of the three exams. Students may also elect to shift the points of any or both of the term tests to the final exam. This election, however, must be made before tests. Students should be aware of the risk involved with such decisions.

TEXT:

Das, B.M. (1998). "Principles of Geotechnical Engineering" Fourth Edition, PWS Publishing Co.

SUGGESTED REFERENCES:

1. Lambe, T.W., and Whitman, R.V. (1979). "Soil Mechanics" John Wiley Publishing Co.

2. Bowles, J.E. (1991). "Physical and Geotechnical Properties of Soils" McGraw-Hill Book Co.

COURSE OUTLINE

1. Soils and Rocks

• 1.1 Rock Cycle and the Origin of Soil
• 1.2 Soil Particles
• 1.3 Clay Minerals
• 1.4 Mechanical Analysis of Soil
• 1.5 Effective Size, Uniformity Coefficient, and Coefficient of Gradation

2. Soil Composition

• 2.1 Weight-Volume Relationships
• 2.2 Unit Weight, Void Ratio, Moisture Content, and Specific Gravity Relationships
• 2.3 Unit Weight, Porosity, and Moisture Content Relationships
• 2.4 Relative Density
• 2.5 Consistency of Soils
• 2.6 Unified Soil Classification System

3. Soil Compaction

• 3.1 General Principles
• 3.2 Standard Proctor Test
• 3.3 Factors Affecting Compaction
• 3.4 Modified Proctor Test
• 3.5 ASTM and AASHTO Specifications for Compaction Test
• 3.6 Structure of Compacted Cohesive Soil
• 3.7 Effect of Compaction on Cohesive Soil Properties
• 3.8 Field Compaction
• 3.9 Specifications for Field Compaction
• 3.10 Determination of Field Unit Weight of Compaction
• 3.11 Special Compaction Techniques

4. Flow of Water in Soil: Permeability and Seepage

• 4.1 Hydraulic Gradient
• 4.2 Darcy's Law
• 4.3 Coefficient of Permeability
• 4.4 Laboratory Determination of the Coefficient of Permeability
• 4.5 Effect of Temperature on Coefficient of Permeability
• 4.6 Equivalent Permeability in Stratified Soils
• 4.7 Permeability Test in Field by Pumping From Wells
• 4.8 Coefficient of Permeability from Auger Holes
• 4.9 Equation of Continuity
• 4.10 Flow Nets
• 4.11 Uplift Pressure under Hydraulic Structures

5. Effective Stress Concept

• 5.1 Stresses in Saturated Soil without Seepage
• 5.2 Stresses in Saturated Soil with Seepage
• 5.3 Seepage Force
• 5.4 Heaving in Soil due to Flow around Sheet Piles
• 5.5 Effective Stress in Partially Saturated Soil
• 5.6 Capillary Rise in Soil
• 5.7 Effective Stress in the Zone of the Capillary Rise

6. Stresses in a Soil Mass

• 6.1 Normal and Shear Stress along a Plane
• 6.2 The Pole Method of Finding Stresses along a Plane
• 6.3 Mohr-Coulomb Failure Criteria
• 6.4 Determination of Shear Strength Parameters for Soils in the Laboratory
• 6.5 Triaxial Shear Test
• 6.6 Unconfined Compression Test of Saturated Clay
• 6.7 Sensitivity and Thixotropy of Clay

7. Compressibility of Soil

• 7.1 Fundamentals of Consolidation
• 7.2 One-Dimensional Laboratory Consolidation Test
• 7.3 Void Ratio Pressure Plots
• 7.4 Normally Consolidated and Overconsolidated Clays
• 7.5 Effect of Disturbance on Void Ratio-Pressure Relationship
• 7.6 Influence of Other Factors on e-log p Relationship
• 7.7 Calculation of Settlement due to One-Dimensional Primary Consolidation
• 7.8 Compression Index
• 7.9 Swell Index
• 7.10 Settlement due to Secondary Consolidation
• 7.11 Time Rate of Consolidation
• 7.12 Coefficient of Consolidation

8. Slope Stability

• 8.1 Factor of Safety
• 8.2 Stability of Infinite Slopes without Seepage
• 8.3 Stability of Infinite Slopes with Seepage
• 8.4 Finite Slopes
• 8.5 Analysis of Finite Slope with Circularly Cylindrical Failure Surface
• 8.6 Method of Slices

9. Environmental Geotechnology

• 9.1 Landfill Liners-Overview
• 9.2 Geosynthetics, Geotextiles, Geomembranes, and Geonets
• 9.3 Single Clay Liner and Single Geomembrane Liner Systems
• 9.4 Recent Advances in the Liner Systems for Landfills

10. Soil Exploration

• 10.1 Common Methods of Sampling

Project GeoSlam

GeoSlam is a challenging competition in the design and placement of soil layers to comply with specific criteria related to unit weight and the ability to resist compressive forces. This project is for the Civil Engineering students at Union College who are registered in the Soil Mechanics course.

LABORATORY SCHEDULE

Lab (1): Grain size distribution of granular soils (sand).

Lab (2): Atterberg limits of cohesive soils (clay).

Lab (3): Moisture-density relations of soils (compaction test).

Lab (4): Permeability of granular soils (constant head).

Lab (5): Unconfined compressive strength of cohesive soil.

Lab (6): Direct shear test of soils under consolidated drained conditions.

Lab (7): One-dimensional consolidation properties of soils.

Lab (8): Unconsolidated, undrained compressive strength of cohesive soils in triaxial compression.

Lab (9): Slope stability.

Lab (10): Environmental geotechnology.

SPECIFICATIONS OF LAB REPORT

Although students will work in groups, every student will be responsible for submitting a separate report showing his/her own effort. The lab report shall include a cover page with the names of all partners in the group, course and test titles, and date. The report itself shall contain the objective of the test, procedure, a sketch of equipment used, tables of data recorded, presentation of results in charts and graphs, and conclusions. The report should emphasize the technical aspect of the test. Emphasis in grading will be placed on the technical content of the report as well as clarity, creativity, and correctness of writing. This course is worth a W1 credit, therefore all work should be a true reflection of the writing credit to be earned.

WHAT IS COVERED IN EXAMS?

Student Projects