Measurement device for pile displacement and method for use of the same

A system for measuring the displacement of a driven pile, in relation to a fixed reference, the system comprising:

• a support structure transversely spaced from a displacement axis of an associated driven pile to be displaced;
• a radio frequency transmitter including a signal generator of a given frequency and a transmitter antenna, the transmitter antenna securable relative to one of the associated driven pile to be displaced and the support structure used as a fixed reference for the measurement of the displacement of the associated driven pile along the displacement axis,
• when in the secured position the transmitter antenna being positioned on and thereby defining both a transmitter axis parallel to the displacement axis and a center line perpendicular to the displacement axis, the transmitter antenna being configured to emit a radio frequency signal of the given frequency;
• the system further comprising a first radio frequency receiver having a first receiver antenna securable relative to the other of the associated driven pile and the support structure;
• and a second radio frequency receiver having a second receiver antenna securable relative to the other of the associated driven pile and the support structure, when in the secured position, the first and second receiver antennas being positioned along a receiver axis parallel to the displacement axis and the first and second receiver antennas being spaced along the receiver axis on either side of the transmitter antenna and the first and second receiver antennas being spaced along the receiver axis on either side of the center line by a receiver spacing such that the first and second receiver antennas are generally equidistant to the transmitter axis, the receiver axis being transversely spaced from the transmitter axis by an axis spacing, the first and second receiver antennas being configured to detect the radio frequency signal emitted by the transmitter;
• wherein the support structure is fixed relative to an associated ground layer and extends upwardly from the associated ground layer;
• the transmitter antenna, first receiver antenna and/or second receiver antenna that is/are fixed relative to the associated driven pile to be displaced moving with the associated driven pile as it is displaced;
• the system further including a computing system in communication with the first and second receiver antennas and configured to receive a first signal from the first receiver and a second signal from the second receiver, the computing system further including a phase detector configured to detect the differences in phase between the first and second signals;
• and,
• a computer processor to calculate the displacement of the associated driven pile based on the differences in the phase of the first and second signals.