The foundation engineering hand book - manjriker gunaratne – 902 trang

The foundation engineering hand book manjriker gunaratne

[...]... rock Of the several branches of geotechnical engineering, soil and rock mechanics are the fundamental studies of the properties and mechanics of soil and rock, respectively Foundation engineering is the application of the principles of soil mechanics, rock mechanics, and structural engineering to the design of structures associated with earthen materials On the other hand, rock engineering is the corresponding...Page ix Editor Manjriker Gunaratne is a professor of civil engineering at the University of South Florida He completed his pre -engineering education at Ananda College, Colombo, Sri Lanka, receiving the S.A.Wijetileke prize for the highest ranking student Thereafter, he obtained his bachelor of science in engineering (Honors) degree from the Faculty of Engineering, University of Peradeniya,... Analysis According to the texture or the “feel,” two different soil types can be identified They are: (1) coarse-grained soil (gravel and sand) and (2) fine-grained soil (silt and clay) While the engineering properties (primarily strength and compressibility) of coarse-grained soils depend on the size of individual soil particles, the properties of fine-grained soils are mostly governed by the moisture content... counted Details of the test procedure can be found in Bowles (1986) and Das (2002) ASTM 4318 specifies the LL as the water content at which the standard-sized gap is closed in 25 drops of the cup Therefore, one has to repeat the experiment for different trial water contents, each time recording the number of blows required to fulfill the closing condition of the soil gap Finally, the water content corresponding... compression, the pressure of the cell fluid is used to consolidate the soil sample back to the in situ effective stress state that existed prior to sampling On the other hand, in the UU tests, the cell pressure is applied with no accompanying drainage or consolidation, simply to provide a confining pressure 1.4.2.1 Triaxial Testing of Rocks When foundations are designed on rocks, as in the case of pile foundations... Use the Casagrande Plasticity chart shown above Page 8 within a soil mass can be expressed as the summation of the stress contributions from the soil skeleton and the pore fluids as σ '+up =σ (1.2) where σ the total stress (above atmospheric pressure), σis the stress in the soil skeleton is ' (above atmospheric pressure), and up is the pore (fluid) pressure (above atmospheric pressure) The stress in the. .. On the other hand, in completely wet (saturated) soils, the pore fluid is mostly water and the effective stress is completely dependent on the pore water pressure (uw) Then, from Equation (1.2): σ −w '=σ u (1.4a) Using the unit weights of soil (γand water (γ), Equation (1.4a) can be modified to a more ) w useful form as shown in Equation (1.4b): (1.4b) where z is the depth of the location from the. .. application of the above-mentioned technologies in the design of structures associated with rock It is generally observed that most foundation types supported by intact bedrock present no compressibility problems Therefore, when designing common foundation types, the foundation engineer’s primary concerns are the strength and compressibility of the subsurface soil and, whenever applicable, the strength... the Mohr circles for the two stress states can be drawn as shown in Figure 1.10 Then the total strength parameters (also referred to as the undrained strength parameters) can be evaluated from the slope of the direct common tangent, which is the Coulomb envelope (Equation (1.6)), plotted on the Mohr circle diagram as c=4.0 kPa and It is obvious that the generated pore pressure has been ignored in the. .. fine-grained soils are governed by water Hence, the effect of water has to be considered when classifying fine-grained soils This is achieved FIGURE 1.3 Grain (particle) size distribution curves (From Concrete Design Handbook, CRC Press With permission.) Page 5 FIGURE 1.4 Variation of the fine-grained soil properties with the water content by employing the Atterberg limits or consistency limits The . Cataloging-in-Publication Data The foundation engineering handbook/edited by Manjriker Gunaratne. p. cm. Includes bibliographical references and index. ISBN 0-8 49 3-1 15 9-4 1. Foundations—Handbooks,. y0 w1 h0" alt="" Page i THE FOUNDATION ENGINEERING HANDBOOK Page ii This page intentionally left blank. Page iii THE FOUNDATION ENGINEERING HANDBOOK Edited by Manjriker Gunaratne Taylor &. 0-2 0 3-6 113 3-0 (OEB Format) International Standard Book Number-10: 0-8 49 3-1 15 9-4 (Print Edition) (Hardcover) International Standard Book Number-13: 97 8-0 -8 49 3-1 15 9-8 (Print Edition) (Hardcover) Library of