Degradation of soft subgrade soil from slow, large, cyclic heavy-haul road loads: a review

Abstract

Extraction of resources in remote locations can require temporary haul roads to transport extremely large, slow-moving, indivisible loads (e.g., plant, oil–gas production modules, and reactors, weighing in excess of 1000 t) without interruptions. Poor subgrade soils may experience larger cyclic strains and greater cyclic degradation under these conditions than under conventional roads, yet the short engineering life precludes many foundation-strengthening options due to cost. As there is little research into this unique situation, this paper synthesizes research from a broad range of applications to discuss implications on expected soil response. Reference is made to critical state theory and discrete element method (DEM) modelling to develop fundamental concepts considering particle-scale interactions. Cyclic failure is proposed to be a kinematically unstable process, triggered by shear banding on the Hvorslev surface, tensile liquefaction or fabric-governed meta-stable liquefaction; the latter is particularly influenced by stress history and anisotropy. This paper finds pore-water pressure accumulation under load and dissipation between loads are key to cyclic degradation and furthermore to be dependent upon load duration, principal stress rotation, and repetition frequency. For meta-stable, liquefiable soils in particular, inclination of principal stresses is at least as important in assessing failure risk as magnitude of stresses.

Routes for exceptional loads: a new soil mechanics perspective

“…Such an approach would likely be unjustifiably costly and impractical for a temporary road. A better understanding of strength degradation from load and recovery from consolidation in medium/large-strain regimes, as discussed by Krechowiecki-Shaw et al (2016), could achieve a more economic and practical design.…”

“…By taking this into account, an economic observational design, similar in philosophy to that q @ 30% Routes for exceptional loads: a new soil mechanics perspective Krechowiecki-Shaw, Royal, Jefferson and Ghataora of the Cape Kennedy causeway to transport Apollo mission rockets (Peck, 1969), could be achieved: vehicles only traverse once the subgrade strength has sufficiently recovered. For this approach, the following aspects of subgrade behaviour, discussed further by Krechowiecki-Shaw et al (2016), need to be understood.…”

Investigation on shakedown response-behavior of thawed subgrade soils under long-term traffic loading

“…The subgrade is regarded as the support layer for the pavement or railway structures and undertakes the dynamic stress induced by the moving traffic loadings (Beskou and Theodorakopoulos, 2011;Krechowiecki-Shaw et al, 2016;Bian et al, 2018;Cui et al, 2022;Cui et al, 2023a;Cui et al, 2023b;Cui et al, 2024). Under long-term cyclic loadings, the accumulative plastic deformation of subgrade soils gradually increases, where the accumulative plastic deformation induced by long-term traffic loading accounts for the majority (75%-90%) of the total permanent deformation of the subgrade (Li and Selig, 1996;Chai and Miura, 2002;Puppala et al, 2009;Cui et al, 2014;Cai et al, 2018;Lu et al, 2018;Zhang et al, 2020a;Zhao et al, 2024).…”

Study on Optimization of Design Parameters for Precast Pipe Pile Treatment of Soft Soil Subgrade on the Jianghan Plain

“…As China's transportation infrastructure develops rapidly, the construction of highways continues [1] [2]. Currently, major issues limiting social development and the increase in human activities and traffic trips include the scale and condition of current roadways, since many roads have long been in a dilapidated condition and can no longer meet people's travel needs, posing enormous challenges to the carrying capacity of public roads [3] [4] [5]. To ease the strained road environment and improve urban capacity, China has prioritized building city ring expressways in its major central and southern regions.…”