Наука и техника (Dec 2015)
ON ASSESSMENT OF DILAPIDATION IN ELASTO-PLASTIC ELEMENTS OF BUILDINGS
Abstract
The paper proposes a method for assessment of threshold limit and current rates of dilapidation in building elements which is based on the second strength theory. The method is realized in accordance with the criteria of the maximum linear deformations and with due account of reduction in elasticity module value when material creeping occurs. The method is directed on practical assessment of dynamics pertaining to the values of rejection probability or destruction of building elements in the process of its operation during the period of its life cycle.In order to assess dilapidation in elasto-plastic elements of buildings it is necessary to make measurements of deformation growth according to external features, determine average deformation at the beginning of building operation and in specified period of time, threshold limit values of complete relative deformation that characterizes maximum allowable element dilapidation with account of plasticity. Further, а percentage dilapidation scale has been formed on the basis of remainder between average values of initial and threshold limit deformations and with due consideration of plasticity, rejection probability or conjugate conditions with other building elements. So in order to form the percentage dilapidation scale the deformation remainder has been divided by 100 % dilapidation and temporary dilapidation scale has been formed when the remainder is divided by value of element service life. The scales reflect dilapidation rate of the building element through probability growth of its destruction. In this context dilapidated operational period of construction elements and structures should not be included in their rated service life which firstly should guarantee the required security level.
