Analysis of one‐dimensional nonlinear rheological consolidation of saturated clay considering self‐weight stress and Swartzendruber's flow rule

Abstract

Considering the nonlinear rheological properties of saturated clay, the modified unified hardening (UH) constitutive relation was introduced to describe the nonlinear rheological deformation. Meanwhile, Swartzendruber's flow law was used to simulate the non-Darcian flow of pore water in the progress of rheological consolidation. Consequently, a nonlinear rheological consolidation model (NRCM), for one-dimensional consolidation, that simultaneously incorporates nonlinear stress-strain-time relationship, Swartzendruber's flow, self-weight stress, and variable permeability coefficient has been developed here. The finite volume method (FVM) was utilized to solve the NRCM system, and its effectiveness was verified by comparing with the existing consolidation data. The parametric analysis results indicate that the soil's nonlinear rheological effect induced the excess pore water pressure (EPWP)'s accumulation in the initial loading. This phenomenon became more significant when considering the self-weight stress or as the initial overconsolidated parameter, soil thickness, and seepage parameter increased. In contrast, it weakened with the increase of external loading. Additionally, considering the self-weight stress slowed down the whole dissipation of EPWP in the initial period of loading. Nevertheless, it accelerated the nonlinear consolidation process in the middle and late loading stages.

One‐dimensional nonlinear creep consolidation of soft soils with time‐dependent drainage boundary under construction load

“…It is more obvious under the instantaneous load, which shows that the EPP increases and reaches a certain extreme value before it gradually dissipates. In this regard, scholars 18,32,45 have discussed it under the action of constant load, and the mechanism of this phenomenon is also discussed in more detail in Section 4.3 below. The influence curves of the loading rate on the land settlement are given in Figure 8.…”

“…30 Liu et al 31 used nonlinear creep equations to consider the time effect of the secondary consolidation coefficient, which made the modified nonlinear stress-strain-time equation overcome the disadvantage of unlimited creep over time. Cui et al 32 preliminarily studied the nonlinear creep consolidation mechanism of soft soils based on the modified UH model, but they also ignored the role of construction load and the TDD boundary capacity of boundary conditions.…”

“…This non-Newtonian index flow (NNIF) rule has few parameters and describes the reported data well, 33 so it has gradually gained recognition and popularity among scholars in recent years. Based on this nonlinear flow relationship, researchers 24,32 have preliminarily investigated the influence of the NNIF flow parameter on nonlinear consolidation and viscoelastic consolidation of saturated clay ground. Therefore, in this model, the NNIF rule is further adopted to simulate the NDF characteristic of pore water flow during soft soil creep consolidation.…”

An analytical model for 2D consolidation of unsaturated soil with semi‐permeable boundaries considering self‐weight stress and time‐dependent loading

“…Pu et al found that self-weight stress affects the transportation behavior of contaminants by influencing the consolidation behavior of soil. Besides, Pu et al 29 pointed out that the self-weight stress can greatly change the void ratio and consolidation efficiency when analyzing the benchmark problem for 1D self-weight consolidation. In the study of 1D nonlinear rheological consolidation, Cui et al 30 identified that neglecting the effect of self-weight will overestimate the dissipation of EPWP (excess pore water pressure) in the early stage of loading and underestimate the dissipation of EPWP in the later loading stage.…”

1D elastic viscoplastic consolidation analysis of bi‐layered soft ground under time‐dependent drainage boundary and ramp load

“…investigated the consolidation of single‐layer elastic soil based on this NDF flow model considering the stress variation with time. Cui et al 33–35 . respectively studied the influence mechanism of this NDF rule on the 1D viscoelastic and elastic visco‐plastic consolidation process of homogeneous soft ground.…”