A large-strain model was developed to study the consolidation behavior of soil deposits improved with prefabricated vertical drains and subjected to surcharge and vacuum preloading. The smear effect resulting from the installation of drains was incorporated in the model by taking the average values of permeability and compressibility in the smear zone. The dependence of permeability and compressibility on void ratio and the effects of non-Darcian flow at low hydraulic gradients were also incorporated in the model. The creep effect was also taken into account for secondary consolidation of soft soil deposits. The model was applied to two different embankments located at Suvarnabhumi International Airport, Thailand, and Leneghan, Australia. It was observed that the creep effect led to an additional settlement of 12%-17% after the primary consolidation phase. The study further demonstrated that creep settlements increased with the non-Darcian effect. The difference between surface settlement results with and without the creep effect increased from about 12% to 15% when the non-Darcian parameter (n) increased from 1 to 1.6. However, beyond a threshold value of n >= 1.6, the influence of non-Darcian flow on creep settlement diminished. The value of average and actual effective stresses increased by about 13% and 17%, respectively, when the value of n increased from 1 to 2. However, the impact of n on effective stresses became negligible for values of n >= 2.5. The rate of consolidation decreased approximately by about four times when the permeability ratio ((k) over tilde (u)/(k) over tilde (s)) increased from 1 to 5.

Creep effect has a significant influence on the long-term settlement of foundations in the soft soil ground. Deep cement mixing (DCM) method is commonly used to treat soft soil to against the development of the foundation settlement. However, the long-term creep settlement of foundations reinforced by DCM columns is rarely considered in the industry. In this study, numerical investigations are conducted to analyze the settlement characteristics of PHC pipe pile foundations in soft clay treated by DCM column. The responses of pile long-term settlements and distribution of failure soil under vertical loads are examined. The numerical results show that the modified creep index mu* has a visible effect on the long-term settlement and stability of pile foundation. When mu* exceeds 0.01, there is a large risk of pile failure under long-term loading. The deep mixing method exhibits well in controlling long-term settlements of PHC pipe pile foundation, and improve the stability of the pile foundation effectively. From the economic consideration, the reasonable volume of soil reinforcement area is about 15 m3-20 m3. Finally, based on the numerical results, two prediction equations for the long-term settlement of PHC pipe pile foundations under two typical reinforcement radii are proposed in this study.

The delayed settlement of foundations due to soil consolidation, creep or particle breakage can alter the internal load distribution and differential settlements in a superstructure through soil-structure interaction (SSI). The study introduces a novel methodology to simulate time-dependent SSI that overcomes the complexity of incorporating the time-dependent behaviour of foundations into routine SSI analysis. The proposed approach represents the superstructure as a condensed stiffness matrix, and replaces the foundations and underlying soils with macro-element foundation models that encapsulate the foundation-soil interaction into load-displacement relationships derived from constitutive models. To examine the performance of the proposed method, a macroelement model for time-dependent analysis of shallow foundations on sand was integrated with structural analysis to simulate two tests performed in a geotechnical centrifuge on a 3D-printed aluminium framed structure supported by footings on sand. The simulated responses of the superstructure and foundations were found to agree well with those observed in the centrifuge tests. Parametric analyses were conducted to investigate the effect of loading history, load level on the superstructure, and creep tendency of soil on postconstruction load redistribution and differential settlements. The findings suggest that creep of foundations on sand facilitates load redistribution in the structure from heavily loaded sections to lightly loaded sections. Moreover, post-construction load redistribution depends on the differential creep between footings and should be considered for structures that are quickly constructed or at high levels of strength mobilisation (low factor of safety). Overall, the study highlights the potential of the proposed methodology in analysing the time-dependent SSI and its applicability in practical SSI analysis.

Overlying river can accelerate the creep of the inner dump, so to master the creep characteristics of the overlying river can provide a theoretical basis for mine safety and discharge optimization. Taking the overlying river inner dump of Yuanbaoshan open-pit coal Mine in China as the research object, a design scheme is proposed to divide it into rolling zone and non-rolling zone. Based on the creep model obtained by in-situ deformation monitoring and laboratory rheological test, the creep evolution law and deformation of overlying channel after soil discharge, slope morphology and advancing position are simulated and analyzed. The results showed that the creep variable in the (non-) rolling zone had a nonlinear upward trend with time, and the initial upward trend was large. The maximum vertical and horizontal creep in the rolling area was located in the middle and upper part of the rolling line, while the maximum vertical and horizontal creep in the dump was located in the middle and upper part of the non-rolling area, respectively. The post-construction settlement and horizontal discharging increased with the increase of the discharge height, and the convergence creep of the top ten years after construction increased approximately linearly with the decrease of the distance from the shoulder of the inner dump. The rolled sand and gravel backfill belonged to the foundation of uniform settlement deformation in general, and the change of slope shape had little effect on the deformation of the slope top in the rolled area. The geoglage elongation in the dam area met the requirements. On the premise of ensuring the stability of the dump, the slope angle of the inner dump can be appropriately increased to increase the capacity of the inner dump. The research results can provide guidance for the construction of inner dump in open pit.