Abstract: The effect of multidimensional load on the permeability of concrete of varied water content is examined in this research by using ZYS-1 coal-rock multifunctional triaxial infiltration apparatus under different test conditions. The change trend of permeability coefficient during the climbing of axial compression, confining pressure, and pore pressure are analyzed, and the curves of permeability coefficient under such conditions are acquired respectively. Results illustrate that the permeability coefficient of concrete is in a negative exponential relationship with axial pressure and confining pressure, but is more sensitive to confining pressure, which is reflected in the swift change of permeability coefficient in the presence of low confining pressure. Under the action of confining pressure or axial compression, the permeability coefficient of concrete tends to be stable, and decreases with the increase of water content and gets less sensitivity to water content. The research findings are of great significance to enhancing the durability of concrete and the long-term performance of bridges.

Key words: concrete, permeability, triaxial osmometer, axial compression, confining pressure, pore pressure, moisture content, characteristic curve of permeability coefficient