| Popis: |
Currently, in the road sector of the Russian Federation, there has been a modernization of the system of operation of the road complex. In this regard, there is a tendency to introduce new technologies for monitoring the condition of road pavements. One of these is the high-performance FWD dynamic loading drum set, which allows you to measure pavement trough bowls. In this paper, examples and models are given to evaluate the reliability of the results from the FWD installation, as well as the dependence of the experimental and software data on the deflection bowl of the road structure. The relevance of the study is due to the fact that a significant reworking of methods for calculating non-rigid pavements and the creation of a new method for predicting fatigue damage is being carried out. Nevertheless, the application of this empirical dependence requires an assessment of its adequacy and the possibility of using layers for structures and materials used in the practice of the Russian Federation. It is possible to solve this problem by comparing the actual values of tensile deformations with the calculated values determined on the basis of the mechanical-mathematical model of the stress-strain state of the road structure. The sections of the M-4 “Don” and M-3 “Ukraine” federal highways were chosen as experimental constructions that were used to work out methods for calculating tensile deformations. Measurements at these sites were carried out by installing shock loading FWD every 100 m. At the same time, at each impact impact, the plates of the coating deflection were recorded. Based on the resulting bowls of the deflections, tensile deformations were calculated at the lower boundary of the package of asphalt concrete layers. Next, a statistical processing of the measurements of the deflection bowl was made. To assess the adequacy of the results obtained, the American mathematical model MnLayer was applied. During the calculation, the main parameters of the stress-strain state, including tensile deformations, were determined. Analyzing the data obtained from the calculation of tensile stresses in mathematical models of given road structures, a comparative graph was constructed illustrating the dependence of the actual deflection cup indicators with those obtained in the MnLayer program. |
