Theoretical Foundation Engineering
Featuring an easy-to-understand format where detailed mathematical treatment is kept to a minimum, this in-depth book provides numerous charts, drawings, and illustrations to illuminate the problems and theory.
TABLE OF CONTENTS Theoretical Foundation Engineering
4.9: BEARING CAPACITY OF FOUNDATIONS ON ANISOTROPIC SOIL EXTENDING TO A GREAT DEPTH
4.9 BEARING CAPACITY OF FOUNDATIONS ON ANISOTROPIC SOIL EXTENDING TO A GREAT DEPTH
Foundations on Sand ( c=0)
Most natural deposits of cohesionless soil have an inherent anisotropic structure due to their nature of deposition in horizontal layers. Initial deposition of the granular soil, and subsequent compaction in the vertical direction, causes the soil particles to take a preferred orientation. For a granular soil of this type, if the direction of application of deviator stress makes an angle i with the direction of deposition of soil (Fig. 4.28a), then the friction angle will be ?. The soil friction angle ? can be approximated in a form (Meyerhof, 1978)
Figure 4.28: Continuous rough foundation on anisotropic sand deposit.
where
| ? 1 | = | soil friction angle with i=0 |
| ? 2 | = | soil friction angle wiht i = 90 |
Figure 4.28b shows a continuous (strip) rough foundation on an isotropic sand deposit. The slip lines in the soil at ultimate load are also shown in the figure. In the triangular zone (Zone 1) the soil friction angle will be ?= ? 1. However, the magnitude of ? will vary between the limits of ? 1 and ? 2 in Zone 2. In Zone 3, the effective friction angle of the soil will be equal to ? 2,
Meyerhof (1978) has suggested that the ultimate bearing capacity of a continuous foundation on an anisotropic sand can be calculated by assuming an...
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