Plastic blind drains are underground engineering facilities used for immersion treatment of pollutants and lowering the groundwater level. They are made of materials such as polypropylene (PP) and are usually located underground. They consist of a series of interconnected pipes, Wells and sieve holes.

Plastic blind ditches are in the form of a three-dimensional network, with various structural forms such as rectangular, hollow matrix, and hollow circular. Their void ratio is 80-95%, making them suitable for both spatial composition and management, and they are lightweight. Their compressive strength is more than ten times that of tubular resin structures, so there is no need to worry about them being damaged by soil pressure.

Blind ditches refer to the use of the concave-convex form similar to Braille to change the slope of water flow, allowing water to remain in the blind ditches and thereby reducing the immersion and corrosion of the dam body by groundwater. The reasons why the blind ditches of the dam should be connected to the drainage ditches are as follows: it can make the position of the blind pipes accurate and reasonable, so that the blind pipes can run as far as possible in the low-lying areas of the base surface and the places with water outlet points