Application of georadiolocation method for nondestructive control of the condition of hard-type roads

Abstract

Application of the georadiolocation method when inspecting hard-standing highways allows to measure the structural layers of the road and provides a continuous survey of the subgrade. The main advantage of this method is the high detail of the survey section and its productivity. GPR surveying is possible on the move with the use of a vehicle. The resolution capability of the survey depends on the frequency of the sounding pulse of GPR. To measure the structural layers of the pavement, as a rule, use antennas with central frequencies of 900 MHz and more, which provide an accuracy of measuring up to 1 cm. When determining the power and degree of homogeneity of drainage layer of soil, lithological partitioning of the embankment, search for local heterogeneities, which may be associated with different degrees of decompaction and humidity of soils, low-frequency antennas (500, 300 MHz) are used, allowing to study the section to a depth of 10 m at a resolution capacity of 0.3-0.5 m. To identify the layers on the GPR and determine the velocities of electromagnetic waves in the structural layers of the road, the drilling data are involved. Regression analysis is carried out on the boring data, which allows to reveal the character of functional connection between the thickness of the layers and the double travel time of electromagnetic waves. As the studies have shown, the correlation coefficient between these parameters is quite high (0.7 and more), which provides sufficient accuracy in determining the power of the structural layers.