The prevention and control of seepage deformation in soft foundations mainly involves adopting effective anti-seepage and drainage pressure-relief measures for the foundation. Foundation anti-seepage can be divided into:
　　(1) Vertical anti-seepage (vertical anti-seepage includes constructing cutoff tooth walls, installing sheet pile curtains, clay-cement grouting curtains, concrete diaphragm walls, caissons and open caissons, etc.).
　　(2) Horizontal anti-seepage (horizontal anti-seepage commonly uses clay blankets. In addition, to reduce seepage through the dam body or the exit gradient and prevent seepage deformation of the downstream foundation or toe, treatment measures such as filter layers, filter weighting berms, or relief wells are adopted).