1CVEN 7718 Engineering Properties of Soils Course Syllabus and Schedule General Information Professor: John S. McCartney, Ph.D. Office: ECOT 541 Office hours: By appointment (no HW questions 1 day before due date) E-mail: [email protected] Class: Time: Spring 2012, Tuesday-Thursday 11:00am - 12:15am Room: ECCE 1B47 Lab: Time: TBD Room: ECCE 1B59 Textbook: No textbook is required for this class. Handouts and reference articles will be posted on CULearn throughout the semester. Optional reference texts that you may want to consult are: Shear Strength of Cohesive Soils (1960). Boulder, CO. ASCE. Duncan and Wright (2005). Soil Strength and Slope Stability. Wiley. Terzaghi Peck and Mesri (2005) Soil Mechanics in Eng. Practice. Wiley. Mitchell and Soga (2005). Fundamentals of Soil Behavior. Wiley. Course Description: This is an introductory graduate course covering the stress-strain and strength properties of saturated and unsaturated soils. The purpose of this course is to provide you with a broad understanding of these topics and their history, which will prove useful in other courses, your individual research, reading of the literature, and engineering practice. Information in this class can be applied to the design of earth retaining structures, slope stability, foundation engineering, landfill design, and earth dams. A detailed outline of course topics is attached. We will rely primarily on lectures and laboratory work to develop your understanding of these principles. You will be expected to read and think about material outside class, and to take part actively in class discussions. These discussions will enhance the learning process, allow sharing of experiences, and hopefully make this course more interesting. Course Topics (30 lectures total) 1. Introduction to Engineering Soil Properties (1 lecture) a. Soil properties and inter-relationships b. Categorization of soils from the perspective of shear strength c. Undergraduate Soil Mechanics Review i. Total and effective stress ii. Friction iii. Mohr-Coulomb failure envelopes iv. Mohr’s circles of stress and strain22. Soil Mechanics Concepts Pertinent to Shear Strength of Soils (4 lectures) a. Laboratory measurement of the shear strength of soils i. Direct shear test and interpretation of results ii. Triaxial equipment and testing philosophies (Unconsolidated undrained test, Consolidated drained test, Consolidated undrained test) b. States of stress in geotechnical engineering (isotropic, K0 conditions, normal- and over-consolidation, compression, extension, pure shear, plane strain) c. Alternative Mohr’s diagrams (p-q, t-s, 3 vs. 1-3) and shear strength parameters d. Skempton’s A and B pore water pressure parameters e. Total and effective stress paths in typical laboratory tests (DS, UU, CU, CD) f. Failure criteria (Stress-path tangency and principal stress difference) g. Energy corrections for distortional and hydrostatic deformation 3. Shearing Properties of Dry and Saturated Sands (4 lectures) a. Failure envelope and normal stress effects b. Effects of variables (density/porosity, confining stress, particle crushing, grain shape, grain size, etc.) c. Stress-strain properties (including volumetric and axial strains) d. Critical void ratio and critical state e. Cyclic loading and pore water pressure generation f. Comparisons between triaxial compression, triaxial extension, and plane strain g. Field inference of sand shear strength i. SPT and CPT correlations for sands ii. Shear wave velocity correlations 4. Shearing Properties of Saturated Clays (6 lectures) a. Normally consolidated clay i. Stress-strain relationships ii. Pore pressure relationships iii. Failure envelopes and stress paths b. Over-consolidated clay i. Stress-strain relationships ii. Pore pressure relationships iii. Failure envelopes and stress paths iv. Sampling effects and SHANSEP c. c/p ratio and anisotropy (Ladd and Foote, Edgers and Ladd) d. Strength-water content relationships (Rutledge) e. Correlations with index properties f. Effects of variables (Mineralogy, diffuse double layer effects, sensitivity, compaction water content, cementation, creep, rate of loading, anisotropy) g. Residual shear strength and slickensides h. Field Measurement of Clay Strength i. Vane shear test for clays ii. Block sampling and in-situ shear tests 5. Estimation of Soil Parameters for Numerical Modeling using Experimentally-Derived Stress-Strain Curves (3 lectures) a. Duncan and Chang model to model nonlinear stress-strain curves b. Tangent and secant moduli from triaxial testing c. Effect of strain level on the magnitudes of shear and compression modulus d. Poisson’s ratio36. Experimental Validation of the Cam Clay Model (4 lectures) a. Review of framework and theoretical basis b. Predicted behavior of NC and OC clays c. Experimental verification 7. Shear Strength of Unsaturated Soils (5 lectures) a. Soil water retention curve of unsaturated soils b. Measurement and control of suction and degree of saturation in triaxial testing c. Independent stress state variables and extended effective stress concepts i. Fredlund and Morgenstern (1977) ii. Khalili and Khabbaz (1998), Lu and Likos (2006), Lu et al. (2010) d. Shear strength of unsaturated soils i. Independent stress state variables: Vanapalli et al. (1996) ii. Single effective stress: Lu et al. (2010) e. Constitutive modeling: Barcelona Basic Model and the Wheeler Model f. Relative importance of strength, compressibility, and small-strain modulus 8. Thermal Behavior of Soils (3 lectures) a. Impact of temperature on soil properties (compression indices, critical state line) b. Thermally induced volume change and modifications to the Cam-Clay model c. Impact of temperature on the preconsolidation stress of NC and OC clays d. Thermal softening of the yield surface Laboratory Exercises: 1. Introduction to laboratory testing and equipment (fittings, seals, etc.) (no report) 2. Direct shear tests (loose and dense sands) 3. Unconsolidated undrained triaxial test (compacted clay) 4. Consolidated undrained test with pore water pressure measurement (OC clay) Course Grade Distribution Homework 20% Lab Reports 20% Exam 1 20% Exam 2 20% Exam 3 20% Total 100% Course Schedule - I will occasionally have to miss a class to attend