Integrally-arranged and externally-wrapped double-layered water discharging body and middle concrete combined pile and construction method

The present invention relates to a built-in double outer drainage and the intermediate concrete piles in combination, by the inner annular drainage body pile, pouring concrete thin Piles, outer annular drainage body pile, pile tip precast, reinforced concrete precast lid plates; precast pile tip provided at the bottom of the composite pile, the pile is provided with four apex surface an annular groove for limiting the positions of the immersed tube; precast reinforced concrete cover plate disposed on top of the composite pile, the inner cover is provided with drainage branch pipe . In the present invention the inner and outer concrete pipe pile drainage body disposed a uniform thickness, can accelerate the rate of consolidation of the soil between the piles, to improve the bearing capacity of the foundation soil, it may also be provided to prevent break when hit by a pile o squeezing effect due to piles and other diseases, with good technical and economic benefits. The present invention further provides a method for the construction of composite piles.