Monitoring Research And Analysis For Slope Stability In Road Broaden Project On Distributed Optical Fiber Sensing Technology

Study on slope stability is always important in road engineering. The complex rock and soil properties of slope makes the research still not very satisfying. Slope instability which pose a great threat to economy and life security should be monitored and studied. Scientific monitoring has important guidance function to study the deformation mechanism of the slope and the potential landslide threat. This paper which rely on slope monitoring of road widening project in Qingdao try using BOTDA technology associated with indoor slope model test and finite element analysis in long-term follow-up survey of slope anchor. The main contents and results are as followed:(1) Through demonstration on conclusions of slope monitoring, slope stability analysis and distributed optical fiber sensing technology along with theoretical principle of BOTDA. The advantages of BOTDA method in slope monitoring are expounded.(2) By using the finite element numerical simulation and strength reduction method with ABAQUS on the model the analysis of the displacement and stress of the slope and the anchor is made to gain the slope deformation law. The deformation of bolt near the top of the slope is the largest and reduced to the bottom. Stress is concentrated at the front in the bolt. It’s basically the same with experiment so that the reliability of the BOTDA method is verified.(3) An indoor slope model is designed to analyze the strain distribution law of bolt along the line in different horizons. it shows that the strain extreme points appears at structural weakness plane and the anchor head. With the Peak loads, the upper part wedge installed firstly. BOTDA is sensitive at the capture of load parts.(4) Three dimensional monitoring system for optical fiber is developed to carry out a long-term monitoring of the actual engineering slope. It concludes that anchor bolts of post engineering is influenced by seasonal factors and there exists presence of strain concentration effect in the anchor head. This paper summarize the law of strain and strain of different slope, different height, different time and different depth. The data show good linear relationship between BOTDA and stress meter.(5) The results of laboratory tests, numerical simulation and engineering practice are of high unity. It proves the accuracy and reliability of BOTDA which worthy of further development in slope monitoring.