Simulation Of Infiltration Of Soil Mixed With Different Components Of Gravels

There are often different sizes of gravels in mining waste land, and their presence changes the physical characteristics of the soil, leading to difference in infiltration. With three different sizes(1.00-2.50cm,2.50-3.50cm and3.50-5.00cm), five different proportions (0,15%,30%,45%and60%) of gravels mixed with soil as materials, their infiltrations were studied. Results showed as follows.1) When gravels were mixed with soil, with the increase their proportion, the values of initial infiltration rate and steady infiltration rate of the mixture increased, while the stable infiltration time reduced, illustrating that the addition of gravel is in favor of soil water infiltration and stable infiltration.2) As the size of particles was not uniform, the size distribution of medium particles was better than that of bigger particles or smaller particles, the initial infiltration rate of that mixed with medium particles was the largest, and the stable infiltration time was the longest.3) By fitting the experimental data with the Kostiakov formula and universal empirical formula, we found that both of them can better express the experimental infiltration process. A further comparison showed that the universal empirical formula is more suitable for simulating the infiltration process of the experimental earth-rock mixture.4) Using hierarchical compaction process, the initial infiltration rate, stable infiltration rate and average infiltration rate of earth-rock mixture is higher than that using mixing compaction process.The results will serve as a reference for forecasting runoff and soil erosion in mining area.