fm Page i Monday, April 16, 2007 3:47 PM Introduction to SOIL MECHANICS LABORATORY TESTING 45628_C000.fm Page ii Monday, April 16, 2007 3:47 PM 45628_C000.fm Page iii Monday, April 16, 2007 3:47 PM 45628_C000.fm Page iv Monday, April 16, 2007 3:47 PM CRC Press Taylor & Francis Group 6000 Broken Sound Parkway NW, Suite 300 Boca Raton, FL 33487-2742 © 2007 by Taylor & Francis Group, LLC CRC Press is an imprint of Taylor & Francis Group, an Informa business No claim to original U. Government works Printed in the United States of America on acid-free paper 10 9 8 7 6 5 4 3 2 1 International Standard Book Number-10: 1-4200-4562-8 (Softcover) International Standard Book Number-13: 978-1-4200-4562-8 (Softcover) This book contains information obtained from authentic and highly regarded sources. Reprinted material is quoted with permission, and sources are indicated. A wide variety of references are listed.
Reasonable efforts have been made to publish reliable data and information, but the author and the publisher cannot assume responsibility for the validity of all materials or for the conse- quences of their use. No part of this book may be reprinted, reproduced, transmitted, or utilized in any form by any electronic, mechanical, or other means, now known or hereafter invented, including photocopying, microfilming, and recording, or in any information storage or retrieval system, without written permission from the publishers. For permission to photocopy or use material electronically from this work, please access www.com (http://www.com/) or contact the Copyright Clearance Center, Inc. (CCC) 222 Rosewood Drive, Danvers, MA 01923, 978-750-8400.
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Introduction to soil mechanics laboratory testing / Dante Fratta, Jennifer Aguettant, Lynne Roussel-Smith. Includes bibliographical references and index. Roussel-Smith, Lynne.1’5136--dc22 2006102407 Visit the Taylor & Francis Web site at http://www.com and the CRC Press Web site at http://www.fm Page v Monday, April 16, 2007 3:47 PM Table of contents Preface .xi List of symbols. xiii Chapter 1 In situ methods.1 In situ soil description and identification .3 Shape and mineralogical composition of coarse-grained soils.2 In situ soil investigation.1 The importance of proper geotechnical investigation .3 In situ testing.1 Standard penetration test .2 Cone penetration test.3 Vane shear test .4 Recording soil exploration results.22 Chapter 2 Physical properties .1 Weight–volume relations .1 Compilation of typical values for soils.2 Water displacement method for the evaluation of soil unit weight .3 Gravimetric moisture content determination using oven drying .fm Page vi Monday, April 16, 2007 3:47 PM 2.4Alternative gravimetric moisture content determination methods .1 Moisture content determination using microwave oven drying (ASTM standard D4643).2 Moisture content determination using the calcium carbide gas pressure tester (ASTM standard D4944).42 Chapter 3 Soil classification .1 Sieve analysis of soils.3 Sample data and calculations.2 Principle of analysis.3 Combined grain size distribution .2 Liquid limit test .3 Plastic limit test .6 Sources of error.5 Soil classification systems.1 Unified soil classification system.4 American Association of State Highway and Transportation Officials (AASHTO) classification system .fm Page vii Monday, April 16, 2007 3:47 PM Chapter 4 Soil construction and field inspection .2 Sample data and calculations.1 Sand-cone test .2 Rubber-balloon-density test.3 Nuclear density test .2 Sand-cone method.3 Sample data and calculations.4 Balloon-density method .5 Sample data and calculations.6 Nuclear density method.
115 Chapter 5 Engineering properties — hydraulic conductivity and consolidation .1 Hydraulic conductivity of soils .2 Hydraulic conductivity tests .3 Constant-head permeability test.4 Falling-head permeability test .5 Sample data and calculations.2 Consolidation of soils.2 The consolidation test.3 Determination of geotechnical engineering parameters .5 Summary of results.7 Sample data and calculations.158 Chapter 6 Engineering properties — shear strength.1 Direct shear test.4 Presentation of results .5 Sample data and calculations.fm Page viii Monday, April 16, 2007 3:47 PM 6.2 Unconfined compression test.2 The unconfined compression test.4 Presentation of results .5 Sample data and calculations.6 Calculations and results .7 Sample data and calculations.205 Appendix A Notes on report writing .207 Appendix B Properties and conversion tables .fm Page ix Monday, April 16, 2007 3:47 PM Preface This laboratory manual was written to aid in the understanding of geotech- nical engineering laboratory testing. This manual is not intended to serve as a complete educational tool informing readers about the history, theory, and practical uses of geotechnical engineering. Instead, it is intended to act in conjunction with soil mechanics textbooks to provide guidance and clarity to undergraduate and graduate students and laboratory technicians. The laboratory procedures detailed within this manual follow the standards established by the American Society for Testing and Materials (ASTM), which is important for accredited commercial laboratories.
This laboratory manual originated from class notes developed for geo- technical engineering classes at Louisiana State University. These notes were expanded upon by faculty and students in the Department of Civil and Environmental Engineering at Louisiana State University over the last 5 years. After further research and work on the manual, the authors decided to share their manual to benefit students at other universities and laboratory technicians at commercial geotechnical laboratories. It is the hope of the authors that this laboratory manual will serve as a classic reference and guide for geotechnical laboratory testing for many years.fm Page x Monday, April 16, 2007 3:47 PM 45628_C000.fm Page xi Monday, April 16, 2007 3:47 PM Acknowledgments The authors would like to thank the students who took the geotechnical engineering laboratory courses and whose comments and ideas were used.
In particular, the authors would like to thank the people who edited the draft, helped collect data, and took pictures to facilitate the demonstration of the different techniques: B. Novoa-Martínez, O. Their great contributions are acknowledged; the remaining errors in the manual are just ours. We would also like to thank Dr.
Tumay, and Dr. Alshibli for their suggestions, corrections, and continuous support. The development of this manual was supported in part by the National Science Foundation and the departments of Civil and Environmental Engineering at Louisiana State University and University of Wisconsin–Madison. Finally, we would like to thank our families for always being on our side.
Dante Fratta University of Wisconsin–Madison Madison, Wisconsin Jennifer Aguettant Baton Rouge, Louisiana Lynne Roussel-Smith Baton Rouge, Louisiana 45628_C000.fm Page xii Monday, April 16, 2007 3:47 PM 45628_C000.fm Page xiii Monday, April 16, 2007 3:47 PM List of symbols a Correction factor for different specific gravities of soil particles a Cross-sectional area of stand pipe A Activity of clay A Area Ac Corrected cross-sectional area Ao Initial cross-sectional area av Coefficient of compressibility C Factor for Hazen’s correlation ca Shear strength intercept Cc Coefficient of curvature Cc Compression index Cd Dispersing agent correction Ck Empirical coefficient Cm Meniscus correction Cr Recompression index Cs Swelling index CT Temperature correction Cu Coefficient of uniformity Cv Coefficient of consolidation Ce Secondary compression d Diameter D Particle diameter D Specimen diameter Dr Odeometer ring diameter Dr Relative density D10 Particle size at 10% passing D30 Particle size at 30% passing D50 Mean particle size D60 Particle size at 60% passing e Void ratio emax Maximum void ratio emin Minimum void ratio eo Initial void ratio F Factory-provided prescale factor F10 Percentage of soil passing sieve No.fm Page xiv Monday, April 16, 2007 3:47 PM F40 Percentage of soil passing sieve No. 40 F200 Percentage of soil passing sieve No. 200 g Acceleration of gravity = 9.81 m/sec2 GI Group index Gs Specific gravity h Soil layer thickness H Specimen length h1, h2 Total heads in constant-head and falling-head parameters Hd Maximum drainage path length Ho Initial height of specimen Hr Ring height ic Refraction critical angle ih Hydraulic gradient k Hydraulic conductivity k@20 C Hydraulic conductivity at 20°C ko Pore factor kt Hydraulic conductivity at temperature T L Distance fallen by a particle in a hydrometer test, effective depth of a hydrometer L Distance between manometers in constant head L1 Distance for hydrometer reading L2 Overall hydrometer length LI Liquidity index M Total mass M## Mass of sieve No. # M##+s Mass of sieve No.
# and retained soils Ma Mass of air Mc Mass of sand in cone Md Mass of dry soil Md+r Mass of dry soil specimen and ring for consolidation test Md+sd Mass of dry soil specimen and dish Md+w+w Mass of the dry soil and wax in water Mj+c+s Mass of jar, can, and sand MP200 Mass of the dry sample passing a No. 200 sieve Mpej Mass of partially empty jar Mr Ring mass Ms Mass of soil Ms+r Mass of soil specimen and ring Msand Mass of sand Msf+r Mass of ring plus specimen for consolidation test Mtot Total dry specimen mass in the sieve analysis Mw Mass of water Mw Mass of wax n Porosity N Normal force N Number of blows in the Casagrande device 45628_C000.fm Page xv Monday, April 16, 2007 3:47 PM N60 Number of blows at 60% energy of the standard penetration test Nmax Maximum normal force No Average of the past four values of Ns taken for prior usage Ns Value of current standardization count OCR Overconsolidation ratio P Corrected percentage of particles diameter for the combined grain Ph Percentage of particles diameter remaining in suspension PI Plasticity index q Foundation pressure qu Unconfined compression strength R Hydrometer reading R Corrected hydrometer reading S0 Surface area of seeping water SL Shrinkage limit Sr Degree of saturation Ss Specific surface Su Undrained shear strength t Time T Shear force T Temperature t1 Time near head of the initial portion of curve t2 = 4*t1 t50 Time corresponding to 50% consolidation t90 Time corresponding to 90% consolidation Tf Torque at failure ue Excess pore water pressure V Total volume V Volume of flowing water for permeability test v Velocity of water at 20°C V1 Seismic velocity in layer 1 V2 Seismic velocity in layer 2 Va Volume of air Vb Hydrometer bulb volume Vd Volume of dry soil pat Vd Volume of the sodium hexametaphosphate solution Vf Final reading on volume indicator for the balloon density method Vh Hole volume for balloon density method Vo Initial reading on volume indicator for the balloon density method Vs Volume of solids Vseep Volume of seeping water Vv Volume of voids Vw Volume of water Vw Volume of wax 45628_C000.fm Page xvi Monday, April 16, 2007 3:47 PM W Total weight w Water content Wa Weight of air = 0 N wLL Liquid limit wop Optimum water content wPL Plastic limit Ws Weight of soil wSL Shrinkage limit Ww Weight of water Xd Concentration of the hexametaphosphate in water δh Lateral displacement δv Vertical displacement ∆e Change in void ratio ∆Hf Final change in height ∆Ho Initiation of primary consolidation ∆H50 Midpoint between ∆Ho and ∆H100 ∆H100 Point where two tangents intersect. This point corresponds to the end of primary consolidation ∆t Time for total head to drop h1 to h2 εa Axial strain εv Volumetric strain φ Friction angle φmobilized Mobilized friction angle φpeak Peak friction angle φresidual Residual friction angle γ Unit weight γazv Zero air void unit weight γd Dry unit weight of soil γdmax Maximum dry unit weight γf Fluid unit weight γs Unit weight of solid particles γsand Unit weight of sand γsat Saturated soil unit weight γw Unit weight of water γwax Unit weight of wax η Viscosity θ Angle ρei Electrical resistivity of layer i ρf Water density at the temperature at the time of measurement for hydrometer test ρw Density of water σ1 Major principal stress σ1max Maximum major principal effective stress σ3 Minor principal stress σ3max Maximum minor principal effective stress σ′ Effective stress 45628_C000.