External strain gauging method for geotextiles

摘要

Measurement of geotextile deformation allows an in-depth understanding of the behavior of geotextiles. However, strain gauging on geotextile poses a challenge as geotextiles are soft and have an uneven fibrous surface. A new strain gauging method is proposed to minimize or eliminate the limitations of the present strain measurement methods. This new method makes use of the idea of attaching gauges "externally" to a thin plastic strip whose ends are connected to the geotextile via two end plates. Hence, the region of geotextile where the strain is measured remains virtually unaffected. The results show that the proposed method is able to measure the true global strain developed in the geotextile with a correction factor much lower and more consistent than that in conventional strain gauging methods. Additional pin joints on both end plates of the proposed system allow the system to realign itself slightly to follow the direction of resulting loading. Hence, the stress registered will be close to the stress in the principal direction and the shearing force can be minimized.