Accession Number : AD0837278

Title :   ERRORS IN STRENGTH TESTS AND RECOMMENDED CORRECTIONS,

Corporate Author : CALIFORNIA UNIV BERKELEY INST OF TRANSPORTATION AND TRAFFIC ENGINEERING

Personal Author(s) : Duncan, J. M. ; Seed, H. Bolton

Report Date : NOV 1965

Pagination or Media Count : 54

Abstract : In any type of triaxial compression test it is necessary to surround the sample by a rubber membrane. Furthermore, in all except vacuum triaxial tests, it is necessary to set up the sample in a pressure cell and apply load to it by means of a piston passing through the head of the cell. When making tests on soils of low permeability, it is common practice to place filter paper drains along the sides of the sample to expedite drainage. Soft saturated clays are usually tested at low pressures and have low strengths. Because the forces involved in testing are so small, the loads carried by filter paper drains, rubber membranes, cell piston friction and end plate friction can have an appreciable effect on the apparent properties of the clay. This report shows that neglecting to correct experimental data for the loads carried by filter paper drains, rubber membranes, cell piston friction and end plate friction leads to an overestimate of both strength and consolidation pressure which increases as a percentage of the measured value as the strength and consolidation pressure decrease. (Author)

Descriptors :   *SOIL MECHANICS), (*CLAY, MUD, TEST METHODS, COMPRESSIVE PROPERTIES, CORRECTIONS, LIQUID FILTERS, PAPER, RUBBER, PISTONS.

Subject Categories : Soil Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE