Displacement Monitoring Based On FBG Sensing Technique And Stability Analysis Of Soil Slope

Landslide is a serious global natural disaster which can cause destruction of buildings, congestion of traffic, casualties and economic losses. Inorder to reduce the damage caused by landslide, scholars have focused the slope safety monitoring and forecasting for many years. With the rapid development of sensing technique, high techniques are applied to monitor and analyze slope stability.In this thesis, influence perception rate was analyzed considering pasted fiber Bragg grating by using ABAQUS. The perception st rain rate is mainly affected by thickness, elastic modulus and Poisson’s ratio. At the same time, the pasted length of fiber sensor is also investigated. To eliminate the influence of matrix material and decrease the thickness of the bonding layer, bare fi ber Bragg gratings are chosen in this study. The temperature self-compensation can be achieved by reasonably distributing the fiber grating sensor s. Through numerical simulation and indoor calibration, the displacement calculation accuracy can be improved by extrapolation. Meanwhile, the traditional displacement integral algorithm is improved as the segmented displacement superposition method whose calculation accuracy is higher than that of the conventional displacement integration algorithm, especially when the deformation is small.Then, accordingtothe limit equilibrium method,the integral solution method for calculating the slope stability coefficient can be achieved. And the correctness of the integral algorithm is verified by analyzing the factors affe cting the stability of slope. Meanwhile, the slip surface searching functions are established based on the displacement information to calculate the safety factor of slopes by the numerical simulation.Finally, a slope model test was conducted to analyze t he slope displacement monitoring based on FBG sensing technique. The displacement monitored by the fiber bragg grating sensor are verified through comparing the deformation measured by PIV technique. Meanwhile, the potential slip surfaces of the slope are calculated. The slope stability factors has been calculated by the theoretical method according to the displacement increment objective functions, which are compared with the results calculated by Geo Studio-slope/w. Thus, the feasibility of monitoring slope displacement and analyzing slope safety using the fiber Bragg grating sensor are validated.