Details
| Original language | English |
|---|---|
| Pages (from-to) | 435-444 |
| Number of pages | 10 |
| Journal | Energy Procedia |
| Volume | 149 |
| Early online date | 8 Sept 2018 |
| Publication status | Published - Sept 2018 |
| Event | 16th International Symposium on District Heating and Cooling, DHC 2018 - Hamburg, Germany Duration: 9 Sept 2018 → 12 Sept 2018 |
Abstract
Within the design process of district heating networks, the soil resistances in axial and lateral pipeline direction are commonly treated independently as friction resistance and bedding pressure. However, at curved segments or near ellbows, these resistances occur simultaneously and affect each other. The state of knowledge regarding this topic is summarized, and it is shown that only limited information exists for this case of loading. Therefore, a three-dimensional finite element model was developed, using the sophisticated concept of hypoplasticity as an advanced constitutive model for the bedding material. This soil model is able to account for dilatancy, barotropy and pycnotropy of granular soils. Subsequently, variations of the loading direction were performed for a reference system. The investigations give a good insight into the behaviour of district heating pipelines under combined loading, showing the interdependency of skin friction resistance and bedding pressure. We present a design approach which incorporates interaction terms, derived from the presented investigations. Results gained from these investigation are then transferred to the academic district heating network design tool IGtH-Heat, to evaluate in which manner the incorporation of coupling terms between bedding and friction resistance influences the pipe-soil interaction. Additionally, a temperature dependent formulation of maximum friction resistance is adopted to incorporate the effects of radial pipe displacement. Thereby we demonstrate that the predicted pipeline's displacement significantly change when these effects are taken into account. Using this new formulation, model predictions are compared to data from full scale field measurements.
Keywords
- buried pipelines, combined loading, numerical modelling, Soil-structure interaction
ASJC Scopus subject areas
Sustainable Development Goals
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In: Energy Procedia, Vol. 149, 09.2018, p. 435-444.
Research output: Contribution to journal › Conference article › Research › peer review
}
TY - JOUR
T1 - Numerical Investigations on District Heating Pipelines under Combined Axial and Lateral Loading
AU - Gerlach, Tim
AU - Achmus, Martin
AU - Terceros, Mauricio
N1 - Funding information: The presented research work was fund ed by the German Federal iM nistry of Economic Affairs and Energy under Grant number 03ET1335B. The support is gratefully acknowledged.
PY - 2018/9
Y1 - 2018/9
N2 - Within the design process of district heating networks, the soil resistances in axial and lateral pipeline direction are commonly treated independently as friction resistance and bedding pressure. However, at curved segments or near ellbows, these resistances occur simultaneously and affect each other. The state of knowledge regarding this topic is summarized, and it is shown that only limited information exists for this case of loading. Therefore, a three-dimensional finite element model was developed, using the sophisticated concept of hypoplasticity as an advanced constitutive model for the bedding material. This soil model is able to account for dilatancy, barotropy and pycnotropy of granular soils. Subsequently, variations of the loading direction were performed for a reference system. The investigations give a good insight into the behaviour of district heating pipelines under combined loading, showing the interdependency of skin friction resistance and bedding pressure. We present a design approach which incorporates interaction terms, derived from the presented investigations. Results gained from these investigation are then transferred to the academic district heating network design tool IGtH-Heat, to evaluate in which manner the incorporation of coupling terms between bedding and friction resistance influences the pipe-soil interaction. Additionally, a temperature dependent formulation of maximum friction resistance is adopted to incorporate the effects of radial pipe displacement. Thereby we demonstrate that the predicted pipeline's displacement significantly change when these effects are taken into account. Using this new formulation, model predictions are compared to data from full scale field measurements.
AB - Within the design process of district heating networks, the soil resistances in axial and lateral pipeline direction are commonly treated independently as friction resistance and bedding pressure. However, at curved segments or near ellbows, these resistances occur simultaneously and affect each other. The state of knowledge regarding this topic is summarized, and it is shown that only limited information exists for this case of loading. Therefore, a three-dimensional finite element model was developed, using the sophisticated concept of hypoplasticity as an advanced constitutive model for the bedding material. This soil model is able to account for dilatancy, barotropy and pycnotropy of granular soils. Subsequently, variations of the loading direction were performed for a reference system. The investigations give a good insight into the behaviour of district heating pipelines under combined loading, showing the interdependency of skin friction resistance and bedding pressure. We present a design approach which incorporates interaction terms, derived from the presented investigations. Results gained from these investigation are then transferred to the academic district heating network design tool IGtH-Heat, to evaluate in which manner the incorporation of coupling terms between bedding and friction resistance influences the pipe-soil interaction. Additionally, a temperature dependent formulation of maximum friction resistance is adopted to incorporate the effects of radial pipe displacement. Thereby we demonstrate that the predicted pipeline's displacement significantly change when these effects are taken into account. Using this new formulation, model predictions are compared to data from full scale field measurements.
KW - buried pipelines
KW - combined loading
KW - numerical modelling
KW - Soil-structure interaction
UR - http://www.scopus.com/inward/record.url?scp=85054062297&partnerID=8YFLogxK
U2 - 10.1016/j.egypro.2018.08.208
DO - 10.1016/j.egypro.2018.08.208
M3 - Conference article
AN - SCOPUS:85054062297
VL - 149
SP - 435
EP - 444
JO - Energy Procedia
JF - Energy Procedia
SN - 1876-6102
T2 - 16th International Symposium on District Heating and Cooling, DHC 2018
Y2 - 9 September 2018 through 12 September 2018
ER -