Long-term Monitoring And Trend Analysis Of Maiiagou Landslide In Three Gorges Project Based On DFOS

Landslide is a high frequency of geological disasters,to the people's lives and property to bring significant losses and threats.The monitoring of landslide is of great significance to the research and prediction of landslide formation,and the continuous innovation of landslide monitoring technology is an important way to improve the level of landslide disaster prevention and mitigation.In this paper,the multi-field DFOS monitoring system of Majiagou landslide in the Three Gorges is constructed by distributed optical fiber sensing technology(DFOS)in the Majiagou landslide of the Three Gorges.The performance test of FBG inclination sensor is carried out.As a result,the theoretical model of the gray system of Majiagou landslide is established,and the development trend of the landslide is predicted.The main achievements of this paper are as follows:(1)Design the overall monitoring scheme of DFOS monitoring and the specific monitoring scheme of deformation field,water field and temperature field.(2)The performance test of FBG inclination sensor was carried out,and the feasibility of the technique applied to landslide monitoring was verified,and the further improvement of the sensor was put forward.(3)The gray system theory is introduced into the slope stability analysis,and the feasibility of the method in the slope stability analysis is demonstrated.The gray system theory model of landslide deformation is established and the modeling steps are introduced.(4)Based on the monitoring project of Majiagou landslide in the Three Gorges,the DFOS monitoring system of Majiagou landslide in the Three Gorges Project was designed and established.The new technology of landslide sensing cable laying and the matters needing attention in the monitoring process were introduced.(5)The DFOS monitoring data of the five-year Majiagou landslide in the Three Gorges are analyzed,and the monitoring results of each field are analyzed.A multi-field data association rule is established between the water field and the deformation field.The results show that the reservoir water level is the most influential factor of the stability of the landslide.When the reservoir water level is increased,the displacement rate decreases and the stability of the landslide increases.When the reservoir water level decreases,the displacement rate increases and the stability of the landslide decreases.(6)Based on the DFOS monitoring data,the theoretical calculation model of the gray system of Majiagou landslide is established,and the development trend of Majiagou landslide is predicted.The results show that the Majiagou landslide still belongs to the creep landslide.