The Feasibility Study On Prestress Monitoring Of Anchor Cable Based On The Sensing Technology Of The Fiber Bragg Grating

The prestressed anchor cable reinforcement technology has been widely used as one 0f the supporting methods in the high slope reinforcement of geotechnical engineering,which owes to its economic and effective characters.The deep study of prestressed anchor cable monitoring technology and its prestressing distribution laws can provide a more accurate data support for the supporting theory of the prestressed anchor cable to ensure the safe operation of anchoring work.In this paper,some of the current cable(rod)monitoring technology is introduced.The feasibility of the distributed fiber Bragg grating monitoring anchor is verified,based on the indoor pull-out test,and then the feasibility of cable damage detection of it is verified,and the effect of bent anchor hole to the transmission of the cable prestress is verified by laboratory test.In order to ensure that the fiber grating sensor can work normally in the anchorage section,which is the key part of anchor engineering,a number of indoor simulations are poured by cylindrical concrete to simulate the real environmental for the test and the fiber grating monitoring and protection device has been successfully developed.The pre-stress transmission law of the prestressed anchor cable is analyzed.The experiment results show that fiber Bragg grating monitoring anchor,which can monitor the damage of anchor cable,is useful for monitoring prestressed anchor cable.The cable prestress losses seriously with the increasing depth and the bent anchor hole also seriously affects the transmission of the cable prestress.As the fiber Bragg grating monitoring system can give 24-hour on-line monitoring,and its characteristics,such as corrosion resistance,emi-free,can meet the long-term service,so it can be widely used in geotechnical engineering for Safety monitoring of the slope support,and it can give a warning,before the cable fails to woke,to avoid the accidents.