Composite soil layer vertical seepage failure mode discrimination method

The invention discloses a composite soil layer vertical seepage failure mode discrimination method. The method comprises the following steps: (1) numbering the soil layer and acquiring soil layer calculation parameters; (2) calculating a critical water head difference according to the critical hydraulic gradient; (3) determining a total water head difference, calculating a calculation bearing water head difference of each soil layer, and starting a first soil layer seepage failure mode discrimination cycle; (4) comparing the soil layer critical water head difference with the soil layer calculation bearing water head difference, and distinguishing the situations according to three conditions; and (5) starting corresponding discrimination cycles according to different discrimination conditions of each soil layer. The concept of bearing water head difference, critical water head difference and not bearing additional water head in soil layer calculation is provided, wherein the concept of seepage force transmissi