Volume change behaviour of saturated clays under drained heating conditions: experimental results and constitutive modeling

Abuel-Naga, Hossam; Bergado, Dennes T.; Bouazza, Abdelmalek; Ramana, G. V.

doi:10.1139/t07-031

Cited by 177 publications

(113 citation statements)

References 24 publications

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“…The reason for this difference may be soil plasticity and contraction upon heating which has been observed in laboratory tests (e.g. Abuel-Naga et al, 2007;Sultan et al, 2002) and is not accounted for in these analyses. …”

Section: Resultsmentioning

confidence: 96%

Numerical modelling of thermo-active piles in London Clay

Gawecka

Taborda

Potts

et al. 2017

Proceedings of the Institution of Civil Engineers - Geotechnica

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Thermo-active foundations utilise heat energy stored in the ground to provide a reliable and effective means of space heating and cooling. Previous studies have shown that the effects of temperature changes on their response are highly dependent on their interaction with the surrounding ground. Consequently, it is necessary to consider this interaction and include both the thermal and mechanical behaviour of the ground in design. This paper addresses this issue by performing state-of-the-art finite-element analyses using the Imperial College Finite Element Program, which is capable of simulating the fully coupled thermo-hydro-mechanical behaviour of porous materials. First, the Lambeth College pile test is analysed to demonstrate the capability of the adopted modelling approach to capture the observed response under thermo-mechanical loading. Subsequently, a detailed study is carried out, demonstrating the impact of capturing the fully coupled thermo-hydro-mechanical response of the ground, the use of appropriate boundary conditions and the uncertainty surrounding thermal ground properties. It is demonstrated that the modelling approach has a large impact on the computed results, and therefore potentially on the design of thermo-active piles. Conversely, the effects of thermal conductivity and permeability of the soil are shown not to influence the pile behaviour significantly.

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Section: Resultsmentioning

confidence: 96%

Numerical modelling of thermo-active piles in London Clay

Gawecka

Taborda

Potts

et al. 2017

Proceedings of the Institution of Civil Engineers - Geotechnica

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“…Model parameters λ =0.178, κ =0.046 and γ =0.135 can be obtained from ref. [18]; e 0 =0.72 and M 0 =0.87 can be obtained from ref. [12].…”

Section: 1 Test Results and Model Predictions Imentioning

confidence: 99%

“…[34]; γ =0.065 is obtained from ref. [18]; suppose ν =0.3. It can be seen in Figure 17 that the proposed model can describe the undrained triaxial stress-strain behavior of normally consolidated MC clay well.…”

Section: Test Results and Model Predictions IIImentioning

confidence: 99%

“…After the discussion on experimental phenomena, a thermoplasticity stress-strain relationship was established and the mathematical formulation of thermoplastic yield function was introduced too. The work of Abuel-Naga et al included some isotropic and anisotropic consolidation tests as well as drained and undrained triaxial tests of several different saturated clays [17,18], and then a thermomechanical model was built based on the modified Cam-clay model [19]. Through application of a temperature-controlled triaxial apparatus, triaxial tests through three different stress paths under different temperatures were carried out by Chen et al [20] to demonstrate that the transformation and strength characteristics of clays were affected a lot by temperature change.…”

Section: Introductionmentioning

confidence: 99%

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UH model considering temperature effects

Yao

Yang

Niu

2010

Sci. China Technol. Sci.

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The influences of temperature on the mechanical behavior of saturated clays are discussed first. Based on the concept of true strength and the revised calculation method of the potential failure stress ratio, the equation of the critical state stress ratio for saturated clays under different temperatures is deduced. Temperature is introduced as a variable into the UH model (3-dimensional elastoplastic model for overconsolidated clays adopting unified hardening parameter) proposed by Yao et al. and then the UH model considering temperature effects is proposed. By means of the transformed stress method proposed by Yao et al., the proposed model can be applied conveniently to 3-dimensional stress states. The strain-hardening, softening and dilatancy behavior of overconsolidated clays at a given temperature can be described using the proposed model, and the volume change behavior caused by heating can also be predicted. Compared with the modified Cam-clay model, the proposed model requires only one additional parameter to consider the behavior of the decrease of preconsolidation pressure with an increase of temperature. At room temperature, the proposed model can be changed into the original UH model and the modified Cam-clay model for overconsolidated clays and normally consolidated clays, respectively. The considered temperature range here is from the melting point to the boiling point of the pore water (e.g. the experimental temperatures (20°C-95°C) mentioned in this paper are within this range). Comparison with existing test results shows that the model can reasonably describe the basic mechanical behavior of overconsolidated clays under various temperature paths. clays, constitutive model, overconsolidation, temperature Citation:Yao Y P, Yang Y F, Niu L. UH model considering temperature effects.

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“…The LY yield curve can be determined by the preconsolidation pressure changes with soil temperature at a constant plastic condition. Based on the experimental results of Hueckle & Baldi (1990) [6], the fitted exponential expression for the LY yield curve is adopted here: Experimental results reported from different types of soils shows that the thermally induced volumetric strain at a constant elevated temperature depends primarily on the stress history (OCR) [8,28]. As the soil changes from a normally consolidated state to an over-consolidated state, the thermally induced contractive volumetric strain keeps decreasing and beyond a certain OCR value it exhibits dilative behavior.…”

Section: Yield Conditionsmentioning

confidence: 99%

Volume change behavior of unsaturated soils under non-isothermal conditions

et al. 2011

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With the development of modern geotechnical engineering practices such as the construction of high level radioactive waste repositories, exploitation and utilization of geothermal resources, energy-saving buildings and underground storage of CO 2 , research into the influence of temperature on the basic mechanical properties of unsaturated soils has become an important issue internationally. By using the work expression and considering the influence of temperature on the basic properties of unsaturated soils, the average soil skeleton stress, modified suction and temperature were selected as state variables of generalized forces in thermodynamics and the soil skeleton strain, saturation and entropy were chosen as state variables of generalized flows conjugate to the variables of generalized forces. Based on the nonlinear multi-field coupled model and by using existing experimental results, an elastic-plastic constitutive model of unsaturated soils under non-isothermal conditions was developed to analyze the influence of temperature on the deformation properties of unsaturated soils. The model was used to predict and analyze the influence of suction and temperature on the deformation properties of unsaturated soils under isotropic conditions, and was successfully verified using experimental results.

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Volume change behaviour of saturated clays under drained heating conditions: experimental results and constitutive modeling

Cited by 177 publications

References 24 publications

Numerical modelling of thermo-active piles in London Clay

Numerical modelling of thermo-active piles in London Clay

UH model considering temperature effects

Volume change behavior of unsaturated soils under non-isothermal conditions

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