ABSTRACT
The bearing capacity of pavement performance is basically influenced by the strength of underlying subgrade, which in turn is significantly affected by its moisture content; the level of its impact depends on the soil type. That is why pavement design specifications in most countries include seasonal (or monthly) adjustment factors for bearing capacity; however, the validity of these factors has been questioned due to the global climatic change. The presented Hungarian research work correlated the multi-decade time series deflection data of trial sections with the precipitation quantity and evaporation parameters of the period before the measurement in order to increase the accuracy of subgrade strength prediction. The investigation covered medium-trafficked, nearly terrain-levelled sections with moisture-sensitive subgrade soil types. Various subgrade strength indicators coming from FWD deflection bowl data performed in several time-points were correlated with the precipitation amount during 0–90 days before measurement and average daily temperature. Moisture balance (interpolated data of nearby meteorological stations to the measurement site) and evaporation were considered.
