Soil Creep Effect on Time-Dependent Deformation of Deep Braced Excavation

Abstract

This paper describes recent advances in the effect of soil creep on the time-dependent deformation of deep braced excavation. The effect of soil creep is generally investigated using the observational method and the plain-strain numerical simulation method. The observational method is more applicable for deep braced excavations in soft clays constructed using the top-down method. The plain-strain numerical simulation method can be conveniently used for parametric analysis, but it is unable to capture the spatial characteristics of soil creep effect on lateral wall deflections and ground movements. The additional lateral wall deflections and ground movements that are generated due to the soil creep effect can account for as large as 30% of the total displacements, which highlights the importance of considering the effect of soil creep in deep braced excavations through soft clays. The magnitude of the displacements due to soil creep depends on various factors, such as excavation depth, elapsed period, unsupported length, and strut stiffness. Parametric analyses have indicated several effective measures that can be taken in practice to mitigate the detrimental effect of soil creep on the deformation of deep braced excavation. Based on the literature review, potential directions of the related future research work are discussed. This paper should be beneficial for both researchers and engineers focusing on mitigating the adverse effect of soil creep on the stability of deep braced excavations.

RETRACTED: A novel back-analysis method for improving predictions of time-dependent ground settlements in deep excavations in soft soils

“…Due to a combined contribution of consolidation and creep of soft soils, the ground settlements induced by deep excavation in soft soils are often time-dependent. Field measurements have indicated that ground settlements persistently increase throughout the entire construction process, including the time required to excavate soil, the time required to install supports, and the elapsed time between them (e.g., [12,13,30]). Through a case study, Harahap and Ou [13] indicated that the contribution of creep to the deformation would increase with time, and that at the final excavation stage, 57.1% of the total ground settlement may result from the creep effect.…”

Soil Heterogeneity Effects on Bridge Piles Deformation under Shield Tunnelling Disturbance

“…The laws of motion of a continuous unity are converted into the discrete version of Newton's laws at the nodes using these methods, and the resultant system of ordinary differential equations is solved numerically using the explicit finite difference technique in time. Additionally, FLAC3D has been used in many tunneling-by-shield tunnel projects and proved to be highly accurate and reliable [54,55].…”

A Practical Design Method to Determine the Replacement Time of Light Embankment

“…At the beginning of the last century, some scholars [25][26][27][28][29] found that the deformation of soil continued to grow with the development of time after the completion of consolidation in tests, which was defined as secondary consolidation. Then, the consolidation of soil was divided into primary consolidation stage and secondary consolidation stage, and the secondary consolidation takes place after the completion of primary consolidation.…”