Experimental Study of Triaxial Test of Gravel Soil in Yili's First Coal Mine

The strength of gravel soil of Yili’s First Mine in different water contents was studied by multifunction static and dynamic triaxial test machine. The results show that （1）The yield limit decreases with the increasing of water content under steady confining pressure, and the greater the confining pressure, the greater the yield point of its axial in the same moisture conditions. （2）The expansion becomes into contraction with increasing moisture content. （3）Strength index of gravel soil becomes smaller with the increase of moisture content. The relationship between friction angle and water contents is . And the relationship between cohesion (or bite force) and water contents is . The results provide a theoretical basis for shaft design and construction of Yili’s First Mine.