Valve type expanding pile shoe, prestressed pipe pile grouting device and construction method

The invention discloses a valve type expanding pile shoe, a prestressed pipe pile grouting device and a construction method, and belongs to the technical field of pipe sinking construction of prestressed pipe piles. The valve type expanding pile shoe comprises an upper connecting plate, a lower connecting plate, a connecting cylinder, a valve and an air bag. And the valve type expanding pile shoe is fixedly connected with the pile end of the prestressed pipe pile. The valve is connected with the lower connecting piece in a hinged mode and can rotate relative to the lower connecting piece. The periphery of the connecting cylinder is wrapped with an air bag capable of expanding to extrude the valve to unfold. During construction, after the prestressed pipe pile is sunk to reach the preset depth, the air bag is inflated and expanded through the inflation pump to open the valve to form an expanded pile shoe, slurry flows in the expansion direction of the valve to form an expanded head, and therefore the bearing c