A study of deformation and stress of geogrids based on optical fiber sensing technology

As a new type of sensing technology, the optical fiber sensing technology are characterized by high accuracy and sensitivity, and are suitable for deformation measurement. At present, due to the lack of effective packaging protection methods, the deformation monitoring of geogrids by using optical fiber sensors is seldom conducted. In this paper, the packaging structure of the optical fiber sensor is designed. The package structure may solve the problem of coordinated deformation between the optical fiber sensor and geogrids, and prolong the life of the optical fiber sensor. Based on the reinforced soil slope model test, the number of reinforcement layers and spacing of geogrids are selected as variables to study the deformation and stress characteristics of geogrids. The results show that the deformation of upper reinforcement is larger than that of lower reinforcement along the vertical direction, and the maximum strain of the reinforcement is in the area below the loading point. Newly increased geogrids can effectively share the deformation of initial geogrids and limit the lateral normal displacement of the slope, especially the displacement of the upper and middle parts of the slope. Geogrids can remarkably improve the ultimate bearing capacity of slope. This also study indicates that the optical fiber sensor can sensitively monitor the tiny deformation and stress of geogrids. The packaging structure can effectively remedy the shortcomings of the traditional testing methods.