The invention relates to a slope self-drainage anchor rod and a construction method. The self-drainage anchor rod comprises a hollow anchor
pipe, an anchorage device, a
cushion plate and a
siphon, wherein one end of the hollow anchor
pipe is open, the other end of the hollow anchor
pipe is closed, the hollow anchor pipe is wrapped in a filter screen, threads are arranged at the open end of the hollow anchor pipe, water-pervious holes are formed in the rear middle of the hollow anchor pipe, the rear segment of the hollow anchor pipe and a
slurry outlet pipe are perpendicularly connected, the end of the
slurry outlet pipe is sleeved with a
sleeve valve and a
geotextile bag, and on the two sides of the
slurry outlet pipe, the
geotextile bag is clamped and fixed to the hollow anchor pipe through hoops; the lower side of the hollow anchor pipe is obliquely placed in a slope, the relative
height difference between the pipe opening of the hollow anchor pipe and the pipe bottom of the hollow anchor pipe is kept smaller than 7 m, pulp solidifies in the
geotextile bag and is anchored in stable soil, and the front segment of the hollow anchor pipe is anchored to the
cushion plate through the anchorage device; a water suction pipe of the
siphon is inserted in the hollow anchor pipe and stretches to the bottom, the water suction pipe is connected with a drainage pipe and a
balance water outlet device through connector bent pipes on the slope, and a water inlet of the water suction pipe is as high as a water outlet of the
balance water outlet device. The slope self-drainage anchor rod is simple in structure, can achieve anchoring and draining at the same time and is good in drainage effect, easy and convenient to construct and low in manufacturing cost.