Determination of the residual stiffness parameters of defective buildings on the basis of laser mappings of vibrations and solving the inverse problem of dynamics

The article describes a method for estimating the residual stiffness and the level of defect accumulation in buildings and structures based on the analysis of the values of the self-induced vibration parameters determined by a contactless method using a high-precision laser vibration meter. Laser mapping of the natural vibrations process during spectral transformation allows one to experimentally determine the actual dynamic parameters of the structure and the loss of stiffness properties during operation, which in turn determines the quantitative measure of the accumulated defects in the building. On the basis of solving the inverse problem of dynamics, a technique for determining the residual stiffness parameters from expressions of own frequency characteristics corresponding to lower-tone vibrations is developed. The proposed method allows for an integrated (comprehensive) assessment of the residual stiffness of the bearing structures of a building under horizontal impact, without disassembly of the enclosing structures with all the technological advan-tages of surveys arising from this circumstance.