High-Speed Visual Measurement System of Pile Penetration and Rebound Movement for Construction

A number of piles should be driven into the ground by a hammering process in order to make the ground under the structure safe and strong when construction companies build a high structure such as building and bridges. It is essential to determine whether piles are penetrated into the ground enough to support the weight of the structure since ground characteristics at different locations are different each other. This paper proposes a high-speed real-time visual measurement approach for pile movement under hammering by combining a high-speed line-scan camera with a specially designed mark to recognize two-dimensional motion parameters, position and orientation, of a pile. A mark stacking white and black right-angled triangles is used for the measurement, and movement information for vertical distance, horizontal distance and rotational angle is determined simultaneously. Especially, a high-speed line-scan CCD camera whose line rate is greater than 10 KHz improves the measurement performance of dynamic characteristics of a pile at impact instant dramatically.