Soil arching in highway piled embankments subjected to moving shakedown limit loads

Abstract

Shakedown analysis provides the loading variation limit of a structure, under which the plastic deformation occurred in first loading cycles will cease to further develop and the structure will respond purely elastically to the remaining load cycles. This paper investigated the arching in highway piled embankments under moving shakedown limit loads, which was calculated by the shakedown solutions. The shakedown solutions for materials obeying Mohr–Coulomb criterion was firstly presented based on Melan’s shakedown theorem, which utilised elastic stress fields obtained from the full three-dimensional (3D) finite element (FE) method. Finally, the shakedown limit load for pure rolling condition (i.e. only normal load) was applied onto the surface of pavement as a moving vehicle load. The FE results under moving shakedown limit loads captured similar trend with those under the static loads in terms of settlement and vertical stress, but gave the normalised settlement and vertical stress 33 and 24% larger. The soil arching remained existed in the highway piled embankments under moving shakedown limit loads, but was reduced. The inclusion of moving shakedown limit loads increased the vertical stress of the embankment and thus resulted in a reduction of the maximum value of lateral earth pressure coefficient by approximately 38%.

Keywords:

• Soil arching
• shakedown limit loads
• highway piled embankments
• finite element analysis