The Experts below are selected from a list of 207 Experts worldwide ranked by ideXlab platform
Donatella Sterpi - One of the best experts on this subject based on the ideXlab platform.
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investigation on the behaviour of a thermo active Diaphragm Wall by thermo mechanical analyses
Geomechanics for Energy and the Environment, 2017Co-Authors: Donatella Sterpi, Andrea Coletto, Luca MauriAbstract:Abstract The thermo-active Diaphragm Walls are traditional retaining structures that embed heat exchangers for the exploitation of the near surface geothermal energy, used in the thermal conditioning of buildings and infrastructures. The coupled energetic and structural function of these so called energy Walls requires some investigation in order to optimize the embedded circuit and assess the possible occurrence of significant consequences, in terms of temperature variations within the soils mass and thermal effects on the stress/strain state of the structure. In this contribution, the behaviour of an energy Wall is assessed by finite element thermal analyses, that allow to investigate the energy performance and the short and long term influence on the soil temperatures, and by finite element thermo-mechanical analyses, to highlight the Wall geotechnical and structural response. A one year cycle of heating/cooling operating mode of the geothermal system has been considered and the effects have been discussed in terms of soil–structure interaction and structural internal actions. The results show that the thermally induced mechanical effects are not negligible, especially as variations of the internal axial forces and bending moments. Although they seem to be not detrimental to the geotechnical and structural safety, they require a careful evaluation in order to predict possible situations of unexpected overstress conditions.
Luca Mauri - One of the best experts on this subject based on the ideXlab platform.
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investigation on the behaviour of a thermo active Diaphragm Wall by thermo mechanical analyses
Geomechanics for Energy and the Environment, 2017Co-Authors: Donatella Sterpi, Andrea Coletto, Luca MauriAbstract:Abstract The thermo-active Diaphragm Walls are traditional retaining structures that embed heat exchangers for the exploitation of the near surface geothermal energy, used in the thermal conditioning of buildings and infrastructures. The coupled energetic and structural function of these so called energy Walls requires some investigation in order to optimize the embedded circuit and assess the possible occurrence of significant consequences, in terms of temperature variations within the soils mass and thermal effects on the stress/strain state of the structure. In this contribution, the behaviour of an energy Wall is assessed by finite element thermal analyses, that allow to investigate the energy performance and the short and long term influence on the soil temperatures, and by finite element thermo-mechanical analyses, to highlight the Wall geotechnical and structural response. A one year cycle of heating/cooling operating mode of the geothermal system has been considered and the effects have been discussed in terms of soil–structure interaction and structural internal actions. The results show that the thermally induced mechanical effects are not negligible, especially as variations of the internal axial forces and bending moments. Although they seem to be not detrimental to the geotechnical and structural safety, they require a careful evaluation in order to predict possible situations of unexpected overstress conditions.
Zhiyong Xiong - One of the best experts on this subject based on the ideXlab platform.
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thermo mechanical behavior of energy Diaphragm Wall physical and numerical modelling
Applied Thermal Engineering, 2019Co-Authors: Shengshi Dong, Anh Minh Tang, Jeanmichel Pereira, Van Tri Nguye, Ping Che, Zhiyong XiongAbstract:Abstract The paper presents a study of the thermo-mechanical behavior of energy Diaphragm Wall. A physical model, which consists of a small-scale concrete Diaphragm Wall equipped with a heating exchange pipe, was used. A heating test was performed where hot water (at 50 °C) was circulated through a heat exchange pipe for 75 h. The results show that the temperatures in the Wall and in the soil increased quickly during the first 20 h and reached stabilization at the end of the experiment. The temperature increase induced increase of axial strain in the Wall and earth pressure at the soil/Wall interface. In addition to the experiment, a numerical model, using finite element analysis, was used to predict the behavior of the Wall during this experiment. The good agreement between the numerical and the experimental results allows the main phenomena that took place to be explained; heating induces thermal expansion of the Wall that results in the modification in stress in the Wall and at the soil/Wall interface. In addition, since the pipe was located closer to one side of the Wall, the thermal expansion of the Wall was not homogenous, and the Wall bent during heating.
Yi Rui - One of the best experts on this subject based on the ideXlab platform.
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Finite element modeling of thermo-active Diaphragm Walls
'Organisation for Economic Co-Operation and Development (OECD)', 2020Co-Authors: Yi Rui, Yi MeiAbstract:Abstract: There are two major challenges faced by modern society: energy security, and lowering carbon dioxide gas emissions. Thermo-active Diaphragm Walls have a large potential to remedy one of these problems, since they are a renewable energy technology that uses underground infrastructure as a heat exchange medium. However, extensive research is required to determine the effects of cyclic heating and cooling on their geotechnical and structural performance. In this paper, a series of detailed finite element analyses are carried out to capture the fully coupled thermo-hydro-mechanical response of the ground and Diaphragm Wall. It is demonstrated that the thermal operation of the Diaphragm Wall causes changes in soil temperature, thermal expansion/shrinkage of pore water, and total stress applied on the Diaphragm Wall. These, in turn, cause displacements of the Diaphragm Wall and variations of the bending moments. However, these effects on the performance of Diaphragm Wall are not significant. The thermally induced bending strain is mainly governed by the temperature differential and uneven thermal expansion/shrinkage across the Wall
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thermo hydro mechanical coupling analysis of a thermo active Diaphragm Wall
Canadian Geotechnical Journal, 2018Co-Authors: Yi RuiAbstract:Thermo-active Diaphragm Walls that combine load bearing ability with a ground source heat pump (GSHP) are considered to be one of the new technologies in geotechnical engineering. Despite the vast range of potential applications, current thermo-active Diaphragm Wall designs have very limited use from a geotechnical aspect. This paper investigates the Wall–soil interaction behaviour of a thermo-active Diaphragm Wall by conducting a thermo-hydro-mechanical finite element analysis. The GSHP operates by circulating cold coolant into the thermo-active Diaphragm Wall during winter. Soil contraction and small changes in the earth pressures acting on the Wall are observed. The strain reversal effect makes the soil stiffness increase when the Wall moves in the unexcavated side direction, and hence gives different trends for long-term Wall movements compared to the linear elastic model. The GSHP operation makes the Wall move in a cyclic manner, and the seasonal variation is approximately 0.5–1 mm, caused by two fac...
Andrea Coletto - One of the best experts on this subject based on the ideXlab platform.
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investigation on the behaviour of a thermo active Diaphragm Wall by thermo mechanical analyses
Geomechanics for Energy and the Environment, 2017Co-Authors: Donatella Sterpi, Andrea Coletto, Luca MauriAbstract:Abstract The thermo-active Diaphragm Walls are traditional retaining structures that embed heat exchangers for the exploitation of the near surface geothermal energy, used in the thermal conditioning of buildings and infrastructures. The coupled energetic and structural function of these so called energy Walls requires some investigation in order to optimize the embedded circuit and assess the possible occurrence of significant consequences, in terms of temperature variations within the soils mass and thermal effects on the stress/strain state of the structure. In this contribution, the behaviour of an energy Wall is assessed by finite element thermal analyses, that allow to investigate the energy performance and the short and long term influence on the soil temperatures, and by finite element thermo-mechanical analyses, to highlight the Wall geotechnical and structural response. A one year cycle of heating/cooling operating mode of the geothermal system has been considered and the effects have been discussed in terms of soil–structure interaction and structural internal actions. The results show that the thermally induced mechanical effects are not negligible, especially as variations of the internal axial forces and bending moments. Although they seem to be not detrimental to the geotechnical and structural safety, they require a careful evaluation in order to predict possible situations of unexpected overstress conditions.