Physical Properties of Soils
The subject matter of Part I is divided into four chapters. The first deals with the procedures commonly used to discriminate among different soils or amongdifferent states of the same soil. The second deals with the methods and program of soil exploration. The third is concerned
with the hydraulic and mechanical properties of soils and with theexperimental methods used to determine numerical values representative of these properties. The fourth chapter deals with the physical processes involved in the drainage of soils.
CHAPTER 1Index Properties of Soils
ARTICLE 1 PRACTICAL IMPORTANCE OF INDEX PROPERTIES
In geotechnical engineering, more than in any other field of civil engineering, success depends on practicalexperience. The design of ordinary soil-supporting or soil-supported structures is necessarily based on simple empirical rules, but these rules can be used safely only by the engineer who has a background ofexperience. Large projects involving unusual features may call for extensive application of scientific methods to design, but the program for the required investigations cannot be laid out wisely,nor can the results be interpreted intelligently, unless the engineer in charge of design possesses a large amount of experience. Since personal experience is necessarily somewhat limited, the engineeris compelled to rely at least to some extent on the records of the experiences of others. If these records contain adequate descriptions of the soil conditions, they constitute a storehouse ofvaluable information. Otherwise, they may be misleading. Consequently, one of the foremost aims in attempts to reduce the hazards in dealing with soils has been to find simple methods for discriminatingamong the different kinds of soil in a given category. The properties on which the distinctions are based are known as index properties, and the tests required to determine the index properties are...