The influence of the calculated temperature of the asphalt concrete coating layers on the shear stability of the subgrade

Анотація

Problem The strength of the pavement depends significantly on the climatic conditions, which must be taken into account both in the design process and at the stage of calculating the pavement and the working layer of the subgrade. Incorrect selection of design temperatures can lead to a mismatch between the design and actual operating conditions of the structure. Therefore, it is advisable to determine the effect of the calculated temperature of the asphalt concrete coating layers on the shear resistance of the subgrade. Goal. The goal is analysis of the effect of the calculated temperature of the asphalt concrete coating layers on the shear stability of the subgrade. Methodology. To achieve this goal, the finite element method was used to model the stress-strain state of the pavement structure from the action of the transport load. Results. An increase in the calculated temperature of asphalt concrete layers in the temperature range from 20 ºС to 35 ºС (the temperature range of the coating layers when calculating the construction of pavement according to the criterion of shear resistance of subgrade) for every 5 ºС leads to an increase in the main stresses (σ₁, σ₂, σ₃) in soil subgrade by 5 %. Originality. For the first time, an analysis is made of the influence of the calculated temperature of asphalt concrete coating layers on the stress-strain state and shear stability of the working layer of the soil of the subgrade. It was established that an increase in the design temperature for each 1 ºС leads to an increase in active shear stresses in the soil by 1 % and, consequently, to a 1 % decrease in the safety factor of the subgrade. Practical value. The results of this study were taken into account when developing the Handbook of climatic characteristics and climatic zoning of the territory of Ukraine for calculating non-rigid pavement.