Geology Reference
In-Depth Information
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CHAPTER ONE
Introduction
Structures of all types (buildings, bridges, highways, etc.) rest directly
on, in, or against soil; hence, proper analysis of soil and design of foun-
dations are necessary to ensure that these structures remain safe and
free of undue settling and collapse. A comprehensive knowledge of the
soil in a specific location may also be important in other contexts,
including the use of soil as a source of construction material. In order to
obtain such knowledge, soil must be tested, measured, and evaluated to
determine its engineering properties quantitatively. In some cases, such
determination is performed directly on the soil as it occurs naturally in
the field (
in situ
) at a job site. In other situations, soil samples must be
collected from the job site and tested in a soils laboratory to evaluate the
soil's engineering properties. Chapter 2 covers the former case—in-field
testing, or “soil exploration”; most of the rest of the topic deals with the
latter—laboratory testing.
Soil testing is an extremely important step in an overall construction
design project. Soil conditions vary from one location to another; hence,
virtually no construction site presents soil conditions exactly like any
other. It can be extremely important to remember that properties may
vary, even profoundly, within one site. As a result, soil conditions at every
site must be thoroughly investigated prior to preparing detailed designs.
Experienced soil engineers can obtain a fairly good idea of the soil
conditions at a given location through soil exploration and by examining
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