Drainage system for multistage slope of extremely thick complex loose accumulation layer

The invention relates to a drainage system for a multistage side slope of an extremely thick complex loose accumulation layer, which comprises a water collection and drainage system and a maintenance pipe, and the water collection and drainage system is pre-buried in the side slope along the trend of the multistage side slope, is communicated with a ditch at the bottom end of the side slope, and comprises a plurality of drainage rooms which are communicated with one another; the top end of the maintenance pipe is provided with an end cover, and the bottom end of the maintenance pipe is communicated with the water collection and drainage system; the drainage house comprises an arc-shaped non-porous plate, a horizontal porous plate and geotechnical cloth, the arc-shaped non-porous plate is connected with the horizontal porous plate, the arc-shaped non-porous plate serves as the bottom face of the drainage house, the horizontal porous plate serves as the top face of the drainage house, and ...