Soil Arching Effect in Piled Embankments Under Moving Shakedown Limit Loads

Most research conducted so far has investigated the behavior of soil arching in piled embankment under static loads, knowledge on their dynamic behaviors under transient loads of moving vehicles is rather limited in the literature, and therefore it deserves more research attention. This paper presented an investigation of the soil arching effect in the piled embankment under shakedown limit loads. A 3D FE model combined with Melan’s lower-bound shakedown theorem is firstly presented, in which the shakedown limits were calculated as the minimum shakedown multiplier among all layers of the piled embankment by means of a self-equilibrated critical residual stress field. It showed that the shakedown limit loads decreased with the increase of the frictional coefficient, which decreases by approximately 77% when increasing μ from 0.2 to 1.0. The shakedown limit loads for the condition of μ = 0 were then applied onto the surface of pavement as the external traffic loads, which moved at a speed of 60 km/h for 40 cycles. The settlement at the surface of the pavement was found to increase gradually within the first a few load cycles, and then approaches to approximately a steady value, indicating that the piled embankment in a shakedown status. Finally, the soil arching effect under the moving shakedown limit loads was investigated in terms of the settlement profile, vertical stress and earth pressure coefficient both under static and dynamic loads. It showed that the soil arching effect remained existed, while was significantly reduced under the shakedown limit loads.