Experimental study on tensile strength of compacted gravel soil

Tensile strength is an important mechanical property of clay soil. It is used seldom in engineering, and there are few studies on it. In fact, there are a number of geotechnical problems related to the tensile strength of clay, such as cracking in clay, sliding and hydraulic fracturing in the core of earth dam. Tensile strength tests on three kinds of compacted soil samples are carried out. The variations in tensile strength of the soils with the change of dry density, water content and preconsolidation pressure are investigated respectively. The results of the tests indicate that the tensile strength of the soil increases with the dry density increasing, and the increment is obvious. On the other hand, with the increase of the preconsolidation pressure, the tensile strength increases simultaneously, but the increasing rate is small for the range of the preconsolidation pressure varied from 100 kPa to 500 kPa. Moreover, the tensile strength of the soil decreases with the increase of water content to some extent related to the dry densities. Within the investigated ranges of water content, dry density and preconsolidation pressure, the tensile strengths of the soils vary from 20 to 80 kPa.