A new simplified Hypothesis B method for calculating consolidation settlements of double soil layers exhibiting creep

Summary This paper describes a robust and efficient methodology for predicting displacements, deformations, and stresses in geomaterials that are susceptible to creep. The methodology is based on two integration schemes, which consider substepping algorithms. The first scheme is used for integrating space‐time relations in a global sense, whereas the second scheme is used for integrating stress‐stain relations in a local sense. Different from previous studies, both integration schemes are easy to implement and general in the sense that they can be applied to any type of creep law. Through an in‐house finite element simulator, several numerical tests are performed. They include triaxial and wellbore closure analyses considering soft soils and salt rocks. The results show that the combination of both schemes leads to stable and accurate solutions with reduced computational time.

Section: Creep Laws In Geomaterialsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Integration schemes with substepping algorithms for creep analysis in geomaterials

Quevedo

Firme

Roehl

2019

“…Many geotechnical structures such as embankments, retaining walls, slopes, and tunnels show time‐dependent behaviour to some extent . The time‐dependent behaviour of fine grained soils such as clay and silt has been studied extensively in the past . For granular soil, however, the study on the time‐dependent behaviour has started only recently.…”

Section: Introductionmentioning

confidence: 99%

“…[1][2][3][4][5] The time-dependent behaviour of fine grained soils such as clay and silt has been studied extensively in the past. [6][7][8][9][10] For granular soil, however, the study on the time-dependent behaviour has started only recently. Clayey soil, usually referred to as isotach material, follows a classical deformation pattern with time.…”

Section: Introductionmentioning

confidence: 99%

Modelling the time‐dependent behaviour of granular material with hypoplasticity

Wang

Yin

et al. 2018

Summary This paper presents a constitutive model for time‐dependent behaviour of granular material. The model consists of 2 parts representing the inviscid and viscous behaviour of granular materials. The inviscid part is a rate‐independent hypoplastic constitutive model. The viscous part is represented by a rheological model, which contains a high‐order term denoting the strain acceleration. The proposed model is validated by simulating some element tests on granular soils. Our model is able to model not only the non‐isotach behaviour but also the 3 creep stages, namely, primary, secondary, and tertiary creep, in a unified way.

“…Borja and Choo considered the macro‐ and micro‐scales and simulated the “secondary compression” during 1‐D consolidation. Yin and Feng and Feng and Yin proposed a simplified Hypothesis B method to calculate the consolidation settlement for both single and double soil layers exhibiting creep. Wang, Sun, Li, and Ye provided a semi‐analytical solution to Terzaghi's 1‐D consolidation of a viscoelastic soil fractional derivative Kelvin‐Voigt model.…”

Section: Introductionmentioning

confidence: 99%

Study of the 1‐D consolidation behavior of two‐layered soft soils: Parametric studies using a rheological model with viscoplastic body

Zou

Xie

et al. 2018

Summary The governing equations for the coupled processes of consolidation and creep of two‐layered soft soils are established. The Nishihara rheological model is adopted to simulate the elasto‐viscoplastic characteristics of soft soils, disregarding the effects of the soil self‐gravity. A semi‐analytical theory combined with numerical and analytical methods is introduced to solve the governing equations of the one‐dimensional rheological model. The computational procedure and the approximate solutions for two‐layered soft soils subjected to surface loading are obtained for two drainage conditions. The solutions and the computational procedure are used to study the effects of the two layers and constitutive parameters on rheological consolidation behavior of soft soils. It can be concluded that two layers affect the rate of excess pore water pressure dissipation and settlement development. The parametric studies show that when the parameters of the upper layer remain constant, increases in the permeability and elastic modulus in the lower layer accelerate the dissipation of the excess pore water pressure, and meanwhile increases in the viscosity coefficient and viscoplastic limit slows down the dissipation of the excess water pressure.