Circular uniform pressure distribution has been traditionally utilised in the analysis of mechanical-based asphalt pavement. However, both the magnitude along tyre width and length shows non-uniformity. Thus, EverStressFE, a 3D software package, was applied to establish a numerical model of the flexible base asphalt pavement structure under non-uniform vertical tyre contact pressure. Comparisons were made among the distribution of non-uniformity and uniformity on pavement surface deflection, pavement structure shear strain, the tensile strain at the bottom of the asphalt concrete surface layer and the vertical compressive strain on the top of the subgrade. The control index on the design life of the pavement under the non-uniform vertical contact pressure was discussed. The results show that, compared with uniform distribution, convex non-uniform distribution produces larger deflection on the pavement surface and maximum tensile strain at the bottom of the asphalt concrete surface layer, while the concave one generates larger shear strain on the pavement structure. Meanwhile, the non-uniform distribution has a little effect on the vertical compression strain on the subgrade top except for the convex half sine wave non-uniform distribution. And the maximum tensile strain at the bottom along the driving direction is larger than that along the tyre width regardless of the wheel loading distribution. In addition, the damage for the flexible base asphalt pavement structure is permanent deformation, specifically the allowable number of load repetitions to limit rutting for convex half sine wave non-uniform distribution is the smallest among all the computational cases.

The appropriate selection of treatment methods for a soft soil subgrade is critical to highway widening projects. In this paper, plane strain conditions are considered in the analysis of prefabricated vertical drains (PVD) and dry jet mixing (DJM) columns. PLAXIS is used to develop the finite element models for the simulation of PVD and DJM treated embankments over soft soils for highway widening projects. The model results include the settlements during and after embankment construction and the lateral displacements of the subgrade. This paper also investigates the working mechanisms when the two subgrade treatment methods are adopted for the widening of embankments over soft soils by analysing the excess pore water pressure distribution in the soft soils. In-situ embankment tests are used to validate the proposed numerical model. The results show that the conventional PVD method causes a soil arching effect in the old embankment and excessive ground disturbance during construction despite the fact that this method can reduce the post-construction soil settlement and the lateral displacement during construction. In comparison, the DJM treatment can greatly reduce the settlement during construction, the settlement and differential settlement after construction, and the lateral displacements. Finally, several techniques are summarised to improve the conventional PVD method, providing practical value for widening highway embankments over soft soils.

The structural mechanics analysis of the Portland cement concrete pavement (PCCP) is considerably complicated and distinctive. From the application viewpoint, the capabilities and characteristics of two typical professional finite element software products, named KENSLABS and EverFE, are analyzed. The similarities and differences between these two programs are compared. The comparisons focus on some key factors of modeling and solution strategies, such as element type, meshing, traffic load and temperature curling, boundary conditions, and contact conditions. Based on one specific case example, the two software products were conducted to demonstrate their main functions. The research results clarify the performance of the two software products for structural analysis of cement concrete pavement and indicate each application conditions from their respective features, which can provide valuable references for software users and program developers.

In this study, considering the non-uniform action of actual wheel loads, the influence of bonding conditions at the surface layer/base and base/subbase interfaces on the structure of flexible base asphalt pavement was investigated. The mechanical response under two extreme bonding conditions – one with full slip and the other with complete continuity – was calculated by using the three-dimensional finite element software EverStressFE. Moreover, the dynamic evolution of the life of the pavement structure under different bonding conditions was comprehensively explored. The results show that the bonding conditions had different effects on pavement surface deflection, shear strain, flexural-tensile strain, and maximum vertical compressive strain at the top of the subgrade. The life of the pavement structure controlled by fatigue cracking and permanent deformation decreased non-linearly with the gradual deterioration of bonding conditions. The main mode of damages to the pavement structure alternated between permanent deformation and fatigue cracking, thereby increasing the difficulty of design, construction, and maintenance. Compared with the non-uniform action of wheel loads, the bonding conditions had a larger and independent impact on the structure of flexible base asphalt pavements.

An elastoplastic numerical model for calculating the consolidation settlement of wide embankment on soft ground is established using PLAXIS finite element software to investigate the settlement behaviour of soft ground under the wide embankment. The distribution rules are analysed and compared to narrow embankments, such as surface settlements of ground and embankment, lateral displacement of soft ground at the foot of embankment slope and excess pore pressure in soft ground. The influence rule of elastic modulus of soft ground on the settlement of soft ground under wide embankment is discussed. The results show that the settlement distributions of wide and narrow embankments on soft ground are “W” and “V” shapes, respectively. The maximum settlement of wide embankment is near the foot of the embankment slope, which is unequal to the settlement at the centreline of the embankment. The lateral displacement distribution rules of soft ground are both “belly” shaped at the foot of two types of embankments slope. However, the lateral displacement of the wide embankment is larger in each corresponding stage. During the construction period, the excess pore pressure in the soft ground under the wide embankment is much higher than that of the narrow embankment, so the post-construction consolidation time of the wide embankment is longer. Moreover, the macroscopic settlement rule of the wide embankment is still the same with the increase of elastic modulus of soft ground.