Drainage grouting pipe and method of use thereof

A drainage grouting pipe, comprising a perforated steel pipe (1), a plurality of elastic anti-filtration geotextiles (2), a movable stopper (3) and a grouting pipe (4), wherein the perforated steel pipe (1) consists of a front conical tip (1-1), a middle grouting section, a rear hole-free section (1-2) and a steel pipe seal (1-4), and the middle grouting section is provided with a plurality of grouting holes (1-3);

• a surface of the middle grouting section of the perforated steel pipe (1) is seamlessly and circumferentially wrapped by the plurality of elastic anti-filtration geotextiles (2);
• gaps are formed between adjacent elastic anti-filtration geotextiles (2) for injecting grout in the perforated steel pipe (1) into a geotechnical layer of concern;
• the elastic anti-filtration geotextile (2) is formed by sequentially superposing an upper layer of elastic fiber composite geotextile (2-1), a middle layer of elastic nonwoven fabric (2-2), and a lower layer of elastic fiber composite geotextile (2-1);
• the elastic fiber composite geotextile (2-1) consists of warp yarns (2-1-1), weft yarns (2-1-2), and elastic fibers (2-1-3);
• the warp yarns (2-1-1) and the weft yarns (2-1-2) are superposed and crossed with each other forming a criss-cross pattern, and elastic fibers (2-1-3) are woven between adjacent warp yarns (2-1-1) and between adjacent weft yarns (2-1-2);
• the warp yarns (2-1-1), the weft yarns (2-1-2) and the elastic fibers (2-1-3) are provided with pores between each other;
• the grouting pipe (4) extends into the perforated steel pipe (1), and its end is fixedly connected with the movable stopper (3) in a form of a sleeve, and an outer side of the movable stopper (3) is circumferentially wrapped by a rubber ring, through which is the movable stopper (3) is closely attached to an inner wall of the perforated steel pipe (1);
• the movable stopper (3), the middle grouting section of the perforated steel pipe (1), and the front conical tip (1-1) enclose a grouting space communicated with the grouting pipe (4), and the grouting position is located by pulling and inserting the grouting pipe (4);
• the steel pipe seal (1-4) is configured to seal the perforated steel pipe (1), and is provided with a central through-hole and a plurality of water holes (1-4-1), wherein a rubber sealing ring (1-4-2) is attached to the inner wall of the central through-hole, and the grouting pipe (4) passes through the central through-hole and displacement of the grouting pipe (4) is limited by the rubber sealing ring (1-4-2).