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9.4.1.1 Routine Pavement Analysis In practice much routine pavement design is carried out as catalogue-based design. Nevertheless, routine structural analysis and design methods are used as supple­mental design methods where the pavement is considered as a multi-layered elastic system (Amadeus Project, 2000). The layers are characterised by Young’s modulus, Poisson ratio and thickness. The simplest […]

The purpose of this section is to introduce some of the constitutive models devoted to routine, as well as advanced, pavement analysis and design. For all these models, moisture or water pressure are not taken into account. They are written, here, in terms of total stresses — i. e. the effects of pore water pressure […]

With the use of numerical modelling, engineers aim to obtain the displacement fields as well as the stress values (effective stress, pore pressure and suction) in the road and earthworks sub-structure. The numerical modelling allows the understanding of the behaviour of the geostructure and the analysis of an optimal design. In order to be successful, […]

The materials that comprise the lower parts of the road and which form the subgrade are all geomaterials — particulate solids with pore spaces occupied by a combina­tion of water and air in varying proportions. The solid particles are, for the most part, crystalline. They are derived, ultimately, from geological sources. Individually the grains have […]

Lyesse Laloui[22], Robert Charlier, Cyrille Chazallon, SigurOur Erlingsson, Pierre Hornych, Primoz Pavsic and Mate Srsen Abstract This chapter deals with the effects of water on the mechanical behaviour of pavements. The analysis is based on constitutive considerations. Constitutive models devoted to both routine and advanced pavement analysis and design are introduced and both the resilient […]

Tjal2004, developed by VTI, monitors temperature at every 50 mm down to a depth of 2 m. Temperatures are collected twice an hour and distributed via the Internet. The temperature sensors are calibrated to give highest possible accuracy close to 0°C where freezing starts. Trucks, having mobile Internet, pick up the current freezing situation from […]

8.3.5.1 Introduction Spring-thaw load restrictions are often imposed to avoid severe pavement deteriora­tion during periods of reduced bearing capacity. Equipment that enables monitoring of the pavement strength situation is very important for a road’s traffic carrying capacity, as restrictions could be lifted as soon as the pavement regains its capacity. There are projects with this […]

Figure 8.10 and Table 8.1 show the weakening of a road structure after spring thaw. The stiffness modulus E2 of the whole pavement structure measured by the FWD is, on average, 13% lower in the spring time than it is before the next freezing period. According to the FWD indices, the reason is the weakening […]

Figure 8.9 shows the air temperature together with the volumetric water content at Dyrastadir in Nordurardalur in SW Iceland during spring thaw, monitored through an environmental program run by the Public Roads Administration in Iceland. One can clearly see that as the thawing period starts in early March the water content increases, initially close to […]

In cold climates, and with frost susceptible materials, freeze thaw phenomena play a major role in pavement deterioration. Figure 8.8 shows examples of measurements of deflection development, and of water content in the subgrade, performed in a full scale experiment, carried out in Quebec (Savard et al., 2005). The pavement structure consists of 18 cm […]