The importance of boundary conditions on the modelling of energy retaining walls

Makasis, Nikolas; Narsilio, Guillermo A.; Bidarmaghz, Asal; Johnston, Ian; Zhong, Yu

doi:10.1016/j.compgeo.2019.103399

Cited by 41 publications

(16 citation statements)

References 40 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A 3D finite element model developed by the University of Melbourne is employed in this study, using the finite element software package COMSOL Multiphysics to simulate and evaluate the thermal response of GSHP systems [8][9]. The model couples the governing equations of heat transfer (energy balance) and fluid flow (momentum and continuity), and considers conductive heat transfer within the soil, the concrete and pipe walls and convection within the pipes due to the circulating fluid.…”

Section: Numerical Simulations 31 Overviewmentioning

confidence: 99%

“…The model couples the governing equations of heat transfer (energy balance) and fluid flow (momentum and continuity), and considers conductive heat transfer within the soil, the concrete and pipe walls and convection within the pipes due to the circulating fluid. More information and the complete governing equations can be found in [8][9].…”

Section: Numerical Simulations 31 Overviewmentioning

confidence: 99%

“…Thermal insulation is adopted for the induced excavation space in front of the wall. This is considered as a safer approach in terms of operational limits of heat pumps [4] and imposing minimum effect to the thermal comfort within the station in real cases. The model width in the x direction is set to be 1.8 m (the centre-to-centre spacing between the piles).…”

Section: Numerical Simulations 31 Overviewmentioning

confidence: 99%

“…A notable difference between energy piles and energy pile walls, however, is the fact that that the latter systems are not fully surrounded by the ground throughout their depths. This introduced excavation space can be a very significant factor affecting the thermal performance of the energy walls since it can both limit the available thermal storage as well as can introduce an underground space through which heat transfer needs to be carefully assessed [4]. Therefore, it is worth investigating the influence of the embedment depth and the sensitivity of the thermal performance on energy pile walls.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Thermal response of energy soldier pile walls

et al. 2020

Self Cite

View full text Add to dashboard Cite

Utilising foundation systems as heat exchangers has received significant public interest worldwide, as these energy geo-structures can constitute a clean, renewable, and economical solution for space heating and cooling. Despite their potential, the thermal performance of energy retaining walls, especially soldier pile walls, has not been sufficiently studied and understood and thus further research is required. This work utilises the first ever energy soldier pile wall in the currently under-construction Melbourne CBD North metro station as a case study. A section of this wall has been instrumented and monitored by the University of Melbourne. Full scale thermal response tests (TRTs) have been conducted on a single thermo-active soldier pile at two different excavation levels. Thermal response testing field data results are presented in terms of mean fluid temperatures and further analysed to show the potential impact of the excavation level on the structure’s thermal performance. To further explore this impact of excavation depth (or pile embedment depth) and the long-term thermal performance of energy pile walls, a detailed 3D finite element numerical model is developed in COMSOL Multiphysics and validated against the field-testing results. The simulation suggests that thermally activating all the soldier piles in the station can provide enough energy to fulfil the heating and cooling demand of the station and to satisfy partial heating demand to the surrounding buildings. Furthermore, results suggest that current energy pile design approaches may be adapted for designing energy pile walls.

show abstract

Section: Numerical Simulations 31 Overviewmentioning

confidence: 99%

Section: Numerical Simulations 31 Overviewmentioning

confidence: 99%

Section: Numerical Simulations 31 Overviewmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Thermal response of energy soldier pile walls

et al. 2020

Self Cite

View full text Add to dashboard Cite

show abstract

“…Two different conditions were assumed for the wall-air interaction along the exposed face: no heat flux takes place across this boundary (NF) and a wall face maintained at constant temperature equal to the initial temperature ( ) of 15°C (CT), i.e. similar to those adopted in [11].…”

Section: Introductionmentioning

confidence: 99%

Simplified methods for designing thermo-active retaining walls

et al. 2020

View full text Add to dashboard Cite

Thermo-active retaining structures are geotechnical structures employed to provide thermal energy to buildings for space heating and cooling through heat exchanger pipes embedded within the concrete structure. Consequently, the design of these structures needs to consider both the long-term energy efficiency as well as the thermo-mechanical response in terms of stability and serviceability. Transient finite element analyses can be carried out to evaluate the behaviour of thermo-active walls, where the heat exchanger pipes are explicitly modelled, thus requiring three-dimensional (3D) analyses. However, performing long-term 3D finite element analyses is computationally expensive. For this reason, in this study, new approaches are presented that allow the thermal or thermo-mechanical design of thermo-active walls to be carried out by performing two-dimensional (2D) plane strain analyses. Two methods, which are based on different design criteria, are proposed and their performance in replicating the three-dimensional behaviour is assessed. Furthermore, the factors affecting the 2D approximations for the two modelling approaches are evaluated, where particular emphasis is given to the influence of the simulated boundary condition along the exposed face of the retaining wall.

show abstract

Full‐scale experimental and theoretical investigation on wall stress for underground ecological group tanks with four‐circle tangential connections

Zhang,

Sun,

Yang

et al. 2024

Structural Design Tall Build

View full text Add to dashboard Cite

SummaryThe storage safety of edible oil is critical for global and Chinese food security. In this study, a practical underground four‐circle tangential group tank with the steel‐plate and concrete structure based on a grain storage warehouse was firstly introduced, and the measured hoop reinforcement stress of the outer tank wall is discussed. Secondly, a numerical model consistent with the practical underground group tank is established from the measured data. The distribution of the hoop reinforcement stress of the outer tank wall under earth pressure is extracted and analyzed thoroughly. Finally, formulas reflecting the properties of the hoop reinforcement stress distribution are presented based on the theoretical analysis, and their accuracy is verified by comparison with the measured data. It could be conducted from the experimental results and theoretical formulas that the outer tank wall is under compressive pressure station generally, and the compressive stress increases with the increasing of the ring angle until reaching a steady state. Moreover, the hoop stress curve follows a disproportional function approximately. The moment at 180° hoop with 1‐m plate belt follows the arc‐tangent function while the moment has a sudden‐change point at 120°, which has minor effect on the reinforcement of this tank wall. Consequently, additional attention should be paid to the effects of this sudden‐change phenomenon on the associated structures in in the process of designing of underground storage tanks.

show abstract

The importance of boundary conditions on the modelling of energy retaining walls

Cited by 41 publications

References 40 publications

Thermal response of energy soldier pile walls

Thermal response of energy soldier pile walls

Simplified methods for designing thermo-active retaining walls

Full‐scale experimental and theoretical investigation on wall stress for underground ecological group tanks with four‐circle tangential connections

Contact Info

Product

Resources

About