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In the European project SAMARIS, the predictions obtained with ORNI have been compared with the response of a low traffic pavement tested on the LCPC pavement test track. The pavement consisted of: • a bituminous concrete wearing course, with an average thickness of 66 mm; • A 50 cm thick granular base and sub-base (crushed […]

The modelling of permanent deformations of pavements is more complex than the modelling of the resilient behaviour because it is necessary to simulate the response of the pavement to large numbers of load cycles (typically 105-106 cycles), with variable loading and environmental conditions. A programme for the prediction of rutting of low traffic pavements, called […]

The pavement was modelled in 3D, considering visco-elastic behaviour for the bi­tuminous material, and the non-linear elastic Boyce model (Eq. 9.10) for the un­bound granular material and the soil. The material parameters for the bituminous layer were determined from complex modulus tests and the in-situ temperature of the bituminous layer was taken into account in […]

The experimental pavement structure is presented in Fig. 11.11. It had a length of 28 m, a width of 6 m and consisted of: • a bituminous concrete wearing course, with an average thickness of 85 mm; • a granular base (0/20 mm crushed gneiss) with an average thickness of 430 mm; • a subgrade […]

To model the resilient behaviour of pavements, the French pavement laboratory, LCPC, has developed a finite element program called CVCR, which is a part of the finite element code CESAR-LCPC (Heck et al., 1998; Heck, 2001a, b). This program allows the modelling of the response of pavements in 3D, under moving wheel loads, and incorporates […]

Erlingsson (2007) describes two thin pavement structures that were tested in ac­celerated testing by using a Heavy Vehicle Simulator. Both were surface dressed structures, one with 20 cm thick unbound base course layer and the other with the base course divided into a 10 cm bitumen stabilized base over 10 cm unbound base. Both structures […]

The significance of the coupling between heat and water transport will be illustrated using a freezing experiment performed by Mizoguchi (1990). He packed four iden­tical cylinders with Kanagawa sandy loam. Each cylinder was 20 cm long and had an internal diameter of 8 cm. The samples were prepared for the freezing test by bringing them […]

Hansson et al. (2005) made an attempt to illustrate the effect of a rain shower and fracture zone permeability on the subsurface flow pattern using a two-dimensional computer model; thus making the simulation domain more like reality (Fig. 11.6). The properties of the materials used in the various layers of the model road fulfil the […]

11.4.1 Modelling of Moisture Movements Alonso (1998) presents, on the basis of in-situ measurements, relevant aspects of the water content development of pavement layers and its effect on the mechanical characteristics of granular bases and subgrades. A general model for the coupled analysis of transfer processes (water, heat) and stress-strain behaviour of unsatu­rated compacted soils […]

The monolithic approach of coupled phenomena implies identical space and time meshes for each phenomenon. This is not always possible, for various reasons. The coupled problems may have different numerical convergence properties, generally associated with different physical scales or non-linearities. For example, a coupled hydro-mechanical problem may need large time steps for the fluid diffusion […]