Impermeable secant pile and construction method

The impervious secant pile comprises a plurality of plain piles, meat piles are arranged between the adjacent plain piles, and the adjacent plain piles and the meat piles are meshed to form a meshing area; the occlusion area is formed by pouring impermeable concrete; the plain piles except the occlusion area are common concrete piles; and the reinforced piles except the occlusion area are reinforced concrete piles. The invention further discloses a construction method of the anti-seepage secant pile. According to the invention, the occlusion area is poured by adopting the impervious concrete, so that firstly, the impervious grade and the strength grade of the occlusion area are improved, and the pile material performance of the occlusion part is enhanced; secondly, anti-seepage concrete is poured in the occlusion area, and the defect that cracks are prone to occurring at the joint face of new concrete and old concrete between the occlusion area and the plain pile is overcome; and thirdly, the two cambered sur