Fiber optics based system of monitoring load-bearing building structures

Inspection of the technical condition of load-bearing structural elements of buildings and structures in the process of their construction and operation is an important issue at the present time. A fiber-optic monitoring system is proposed as a solution to the problem of early diagnostics of defects and damage to load-bearing building structures. We developed a scheme for testing fiber-optic sensors, which make it possible to control the stress-strain state of monolithic reinforced concrete structures. For testing, a series of monolithic concrete beams of rectangular cross section were reinforced with fiber optics during their manufacturing. The values of mechanical stresses and deformations arising in beams under loading were determined. Using the tested samples as an example, it was established that the proposed fiber-optic monitoring system (FOMS) makes it possible to control stresses and deformations (and to predict the appearance and growth of cracks) in various building structures. The main element of the system is a hardware-software complex capable of estimating the parameters of a light wave at the output of the optical fiber. The distance from the installation site of the data processing unit to the measurement point can cover the area of 30 km. At this, fiber-optic sensors operate without additional power supply from a laser with the power of up to 30 mW. The proposed monitoring system has a low cost of one measurement point, it is easy to install, which is a good alternative to the electronic beacon-recorder device and the development of optical digital technologies in construction.