Experimental Study of Pressure Distribution in Steady Flow inside Drainage Materials

Pressure distribution is of utmost importance in both 1D and 2D analysis of steady flow in coarse-grained porous media. In the present study, the pressure distribution in length and height of the gravel media has been investigated in a experimental for three gradations of small, medium, and large in three lengths of 0.5, 1, and 1.5 meters. A piezometer is used to measure the pressure on the floor and walls of the laboratory flume. Experimental data show that; in the initial parts of the gravel media, the real pressure distribution (recorded in the laboratory) has relatively a good agreement with the hydrostatic pressure, and as the end of the gravel media is approached and the increase of water level curve, the pressure difference increases. The average Mean Relative Error (MRE) between the real pressure and the hydrostatic pressure for the two endpoints of the gravel media for the three gradations mentioned in the 0.5 meter media are respectively equal to 36.34%, 32.36%, and 33.64%, for 1 meter length is equal to 33.63%, 28.17%, and 29.34% respectively and for 1.5 meter length, it is equal to 39.46%, 25.66%, and 27.62% respectively. In other words, to check the steady flow in the coarse-grained porous media, the use of real pressure will increase the accuracy of the calculation process.