A Low-cost Method for Visualization of Small Deformation in Structures Using a Mirror

抄録

In recent years, an “On-site Visualization” method has been proposed to measure the deformation of structure, and to visualize the measured results by different colors of light in real-time for personnel conducting field measurement. Based on this concept, a mechanical method is introduced in this paper to monitor small deformations in tunnel structures such as the cracks of concrete lining. It consists of a rotational structure, which is used to transform the linear relative displacement into the movement of rotation. The other component is a small rectangular mirror which is mobilized to rotate by the rotational structure. An observer can see the reflected image of the colored mark by means of the mirror from a certain distance. If the mirror rotates as the displacement increases, the reflected image of the mark would move at the same time and eventually disappear from the mirror. As a result, the displacement can be identified visually by the changing reflected image of the colored mark and its value can be read directly from the width of the shifted mark. The mirror size and the distance between the observer and the mirror determine the accuracy of the method for measurement. In this paper, the fundamental experiments were carried out to verify the feasibility and effectiveness of the method. The authors believe that this mechanical method could improve the safety management of tunneling, mining and rock slope engineering.