U-shaped groove opening composite structure

The invention provides a U-shaped groove opening composite structure. The U-shaped groove opening composite structure comprises a bottom plate, side walls, a crown beam and surrounding piles. The twoside walls are arranged on the two sides of the bottom plate correspondingly, and a U-shaped structure is jointly formed by the bottom plate and the two side walls. The two rows of surrounding piles are arranged, and each row of surrounding piles are arranged on the outer sides of the two side walls correspondingly. The tops of each row of surrounding piles bear the crown beam. The sides, close tothe side walls, of the crown beam are provided with outer protruding parts, inner concave parts are arranged on the outer side walls of the side walls, each outer protruding part is connected with the corresponding side wall inner concave part in a matched manner, and accordingly the side walls resist vertical floating force. Two connecting beams are used for connecting the corresponding side walls and stop blocks, and ac