Sampling, and Handling of Marine Sediments

Hvorslev (1949) classified soil samples as nonrepresentative, representative, or undisturbed. This classification is made by comparing the state of the sampled soil to that as exists in situ. A nonrepresentative sample is one in which soils from different strata have been mixed, or some of the soil constituents of the sampled soil are missing. Samples that contain scrapings from the well of the borehole or samples with some of the fine particles washed out during sampling fall in this category. A representative soil sample is one in which there is no change in soil constituents but whose structure, water content, or void ratio has been altered. An xmdisturbed sample, ideally, is one that represents the in situ condition. 

It is not possible to obtain an undisturbed sample in all types of soils. A number of devices and techniques have been developed however, the nature of granular materials is such that an undisturbed sample of sand cannot be obtained and in most cases is not necessary. In general, clays or soils exhibiting some degree of cohesion represenf the major area of concern where undisturbed samples are required. Methods and equipment have been devised that will produce an acceptable undisturbed sample. The quality of the sample will depend upon the environment, the methods used, and the properties of the soil. 

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