Infiltration Numerical Calculation And Simulation Formula Study Of Unsaturated Soil

The problems of unsaturated seepage often exist in mining engineering, water conservancy project, traffic engineering, geology engineering and geotechnical engineering. The characteristics and engineering properties of unsaturated soil don't accord with the concept and principle of the classic soil mechanics, what's more, unsaturated seepage flow is hidden in the underground, is hard to predict, and its influence factors is too many, thus it will cause great influence to human being's engineering activities. Therefore, the problem of unsaturated soil has become increasingly urgent research subject. This paper, by theoretical study and experiment research, in-depth researched on the infiltration law of unsaturated soil and the determination of the relational expression between penetration depth and humidity. The main contents of this paper as the follows:(1)Described the basic characteristics of unsaturated soil and the seepage of basic differential equations. On the basis of the unsaturated infiltration theory, the soil and water potential function and their derivative formulas are deduced by Richards's common soil hydraulic constitutive equation, offered to the unsaturated penetration numerical calculation to use.(2)Studied Philip's infiltration rate formula, on the basis of reasonable non-time difference variant computation model, put forward simpler simulation analytical formulas between infiltration depth and humidity, meanwhile, established a new calculation method, transform functional relation between infiltration depth and humidity (such as exponential, logarithmic, power function, and so on) into linear function. Then used the least square method and the appropriate computer program to calculate its correlation factor, and gave high degree of correlation simulating formulas.(3)Made an unsaturated seepage equipment in order to measuring unsaturated soil infiltration depth and drawing the relational curves between infiltration depth and humidity, further elaborated the law of unsaturated seepage, at the same time, introduced the test principle and the device operation. Finally, through the measurement of infiltration depth data, this paper demonstrated and concluded that unsaturated permeability depth simulating formulas are desirable and convenient.