Low-strain double-speed signal averaging detection method for building hollow pile

The invention provides a low-strain double-speed signal averaging detection method for a building hollow pile. The low-strain double-speed signal averaging detection method for the building hollow pile is applied to a pile body of the building hollow pile. The method comprises the steps of determining a knocking point on the surface of the pile top of the building hollow pile; arranging two or more signal acquisition devices on the surface of the pile top of the building hollow pile as measurement points for the pile body of the hollow pile, wherein an included angle of 45 degrees is formed between the position where one of the signal acquisition devices is arranged and the knocking point, and an included angle of 135 degrees is formed between the position where the other signal acquisition device is arranged and the knocking point; when knocking action at the knocking point is received, obtaining a measurement point signal from each signal acquisition device, and obtaining a double-speed test curve containin