Railway tunneling in frozen ground on Bothniabana

Seppo Saarelainen, Leena Korkiala-Tanttu, Harri Kivikoski

Research output: Chapter in Book/Report/Conference proceedingConference article in proceedingsScientific

Abstract

A new railway line was under construction in north-eastern Sweden, along the shoreline of the Gulf of Bothnia.The terrain consisted of Postglacial clay and silt valleys, and ridges of Precambrian bedrock crossed the railway line.The railway level was about 20 m below the surface of the ground.For the design of freezing, a freezing analysis was carried out to determine the pipeline depths and distances, to estimate the necessary time for freezing and to determine temperatures within the frozen zone.To estimate the deformations, displacements and safety level, a mechanical analysis of the tunnel cross-section was carried out.Time- and temperature-dependent mechanical parameters were determined for the actual soils and design temperatures.The analysis was carried out for 12 different phases during tunneling.The estimated displacements for the tunnel arch were negligible, if the temperatures were at or below -15 °C.The freezing was started in May 2002, and completed in September 2002.Tunneling was started in September, and it was completed in November 2002, following with the casting of the final liner. The application of ground freezing in deep excavations and tunnelling in soft soils is not a new idea.It has been widely discussed in ground freezing symposia since the 1970s.There are certain reasons why ground freezing has proved to be recommendable: the applications do not cause any environmental impacts on the site, freezing can be rationally planned, designed and controlled, and it uses the ground itself as a structural element.Ground freezing causes, of course, certain permanent changes to the freezing soils after thaw.Frost action causes ice segregation in the frost-susceptible soils, and results in consolidation settlements after thaw.These can be pre-estimated and evaluated in relation to neighbouring structures, if needed. As a geotechnical procedure, ground freezing has been economically used as an alternative strengthening method, or as the only possible method at many sites.The frozen soil has dramatically higher strength and stiffness than the unfrozen soil.The mechanical behavior is highly dependent on the temperature below freezing point.In frozen soils, the strength and deformations are also time dependent, which means that they have clearly plastic properties that become more and more dominating when frozen temperature rises.Experience, anyhow, has showed that these characteristics allow in normal cases the engineering application of frozen ground as a temporary support in geotechnical engineering, if the specific properties and conditions are properly verified and controlled for the site.The displacements must be in given limits, and the overall safety must be high enough to maintain the continuous construction procedure until the final support has been completed. The Stranneberg tunnel was located in Sweden, at the western coast of the Gulf of Bothnia, five kilometres along the Bothniabana railway line from Örnsköldsvik towards Umeå (Figures 1 and 2).Construction planning for the freezing started in November 2001.Freezing took place in summer 2002 and excavation in the autumn of the same year.The tunnel (100 meters long, 10 meters high and 10 meters wide) required 40,000 cubic metres of soil and weak rock mass to be frozen.Freezing work on the tunnel started in early 2002 with the installation of freezing columns, and the tunnel broke through the frozen section in December 2002.VTT developed and carried out the coupled thermal and mechanical analysis and design of the tunnel, including laboratory determination of design parametres, and monitoring temperatures and displacements during the operation.Lemcon Ltd., the contractor, carried out the ground freezing, excavation, insulation, preliminary shotcreting, and cast the final liner.
Original languageEnglish
Title of host publicationApplied Material Research at VTT
Subtitle of host publicationSymposium on Applied Materials
Place of PublicationEspoo
PublisherVTT Technical Research Centre of Finland
Pages245-256
ISBN (Electronic)951-38-6312-3
ISBN (Print)951-38-6311-5
Publication statusPublished - 2006
MoE publication typeB3 Non-refereed article in conference proceedings
EventInternal Symposium on Applied Materials - Espoo, Finland
Duration: 8 Jun 20068 Jun 2006

Publication series

NameVTT Symposium
PublisherVTT
Number244
ISSN (Print)0357-9387
ISSN (Electronic)1455-0873

Conference

ConferenceInternal Symposium on Applied Materials
CountryFinland
CityEspoo
Period8/06/068/06/06

Fingerprint

Freezing
Tunnels
Soils
Excavation
Frozen soils
Temperature
Shotcreting
Geotechnical engineering
Silt
Distillation columns
Arches
Consolidation
Contractors
Wind tunnels
Ice
Environmental impact
Coastal zones
Insulation

Cite this

Saarelainen, S., Korkiala-Tanttu, L., & Kivikoski, H. (2006). Railway tunneling in frozen ground on Bothniabana. In Applied Material Research at VTT: Symposium on Applied Materials (pp. 245-256). Espoo: VTT Technical Research Centre of Finland. VTT Symposium, No. 244
Saarelainen, Seppo ; Korkiala-Tanttu, Leena ; Kivikoski, Harri. / Railway tunneling in frozen ground on Bothniabana. Applied Material Research at VTT: Symposium on Applied Materials. Espoo : VTT Technical Research Centre of Finland, 2006. pp. 245-256 (VTT Symposium; No. 244).
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title = "Railway tunneling in frozen ground on Bothniabana",
abstract = "A new railway line was under construction in north-eastern Sweden, along the shoreline of the Gulf of Bothnia.The terrain consisted of Postglacial clay and silt valleys, and ridges of Precambrian bedrock crossed the railway line.The railway level was about 20 m below the surface of the ground.For the design of freezing, a freezing analysis was carried out to determine the pipeline depths and distances, to estimate the necessary time for freezing and to determine temperatures within the frozen zone.To estimate the deformations, displacements and safety level, a mechanical analysis of the tunnel cross-section was carried out.Time- and temperature-dependent mechanical parameters were determined for the actual soils and design temperatures.The analysis was carried out for 12 different phases during tunneling.The estimated displacements for the tunnel arch were negligible, if the temperatures were at or below -15 °C.The freezing was started in May 2002, and completed in September 2002.Tunneling was started in September, and it was completed in November 2002, following with the casting of the final liner. The application of ground freezing in deep excavations and tunnelling in soft soils is not a new idea.It has been widely discussed in ground freezing symposia since the 1970s.There are certain reasons why ground freezing has proved to be recommendable: the applications do not cause any environmental impacts on the site, freezing can be rationally planned, designed and controlled, and it uses the ground itself as a structural element.Ground freezing causes, of course, certain permanent changes to the freezing soils after thaw.Frost action causes ice segregation in the frost-susceptible soils, and results in consolidation settlements after thaw.These can be pre-estimated and evaluated in relation to neighbouring structures, if needed. As a geotechnical procedure, ground freezing has been economically used as an alternative strengthening method, or as the only possible method at many sites.The frozen soil has dramatically higher strength and stiffness than the unfrozen soil.The mechanical behavior is highly dependent on the temperature below freezing point.In frozen soils, the strength and deformations are also time dependent, which means that they have clearly plastic properties that become more and more dominating when frozen temperature rises.Experience, anyhow, has showed that these characteristics allow in normal cases the engineering application of frozen ground as a temporary support in geotechnical engineering, if the specific properties and conditions are properly verified and controlled for the site.The displacements must be in given limits, and the overall safety must be high enough to maintain the continuous construction procedure until the final support has been completed. The Stranneberg tunnel was located in Sweden, at the western coast of the Gulf of Bothnia, five kilometres along the Bothniabana railway line from {\"O}rnsk{\"o}ldsvik towards Ume{\aa} (Figures 1 and 2).Construction planning for the freezing started in November 2001.Freezing took place in summer 2002 and excavation in the autumn of the same year.The tunnel (100 meters long, 10 meters high and 10 meters wide) required 40,000 cubic metres of soil and weak rock mass to be frozen.Freezing work on the tunnel started in early 2002 with the installation of freezing columns, and the tunnel broke through the frozen section in December 2002.VTT developed and carried out the coupled thermal and mechanical analysis and design of the tunnel, including laboratory determination of design parametres, and monitoring temperatures and displacements during the operation.Lemcon Ltd., the contractor, carried out the ground freezing, excavation, insulation, preliminary shotcreting, and cast the final liner.",
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Saarelainen, S, Korkiala-Tanttu, L & Kivikoski, H 2006, Railway tunneling in frozen ground on Bothniabana. in Applied Material Research at VTT: Symposium on Applied Materials. VTT Technical Research Centre of Finland, Espoo, VTT Symposium, no. 244, pp. 245-256, Internal Symposium on Applied Materials, Espoo, Finland, 8/06/06.

Railway tunneling in frozen ground on Bothniabana. / Saarelainen, Seppo; Korkiala-Tanttu, Leena; Kivikoski, Harri.

Applied Material Research at VTT: Symposium on Applied Materials. Espoo : VTT Technical Research Centre of Finland, 2006. p. 245-256 (VTT Symposium; No. 244).

Research output: Chapter in Book/Report/Conference proceedingConference article in proceedingsScientific

TY - GEN

T1 - Railway tunneling in frozen ground on Bothniabana

AU - Saarelainen, Seppo

AU - Korkiala-Tanttu, Leena

AU - Kivikoski, Harri

PY - 2006

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N2 - A new railway line was under construction in north-eastern Sweden, along the shoreline of the Gulf of Bothnia.The terrain consisted of Postglacial clay and silt valleys, and ridges of Precambrian bedrock crossed the railway line.The railway level was about 20 m below the surface of the ground.For the design of freezing, a freezing analysis was carried out to determine the pipeline depths and distances, to estimate the necessary time for freezing and to determine temperatures within the frozen zone.To estimate the deformations, displacements and safety level, a mechanical analysis of the tunnel cross-section was carried out.Time- and temperature-dependent mechanical parameters were determined for the actual soils and design temperatures.The analysis was carried out for 12 different phases during tunneling.The estimated displacements for the tunnel arch were negligible, if the temperatures were at or below -15 °C.The freezing was started in May 2002, and completed in September 2002.Tunneling was started in September, and it was completed in November 2002, following with the casting of the final liner. The application of ground freezing in deep excavations and tunnelling in soft soils is not a new idea.It has been widely discussed in ground freezing symposia since the 1970s.There are certain reasons why ground freezing has proved to be recommendable: the applications do not cause any environmental impacts on the site, freezing can be rationally planned, designed and controlled, and it uses the ground itself as a structural element.Ground freezing causes, of course, certain permanent changes to the freezing soils after thaw.Frost action causes ice segregation in the frost-susceptible soils, and results in consolidation settlements after thaw.These can be pre-estimated and evaluated in relation to neighbouring structures, if needed. As a geotechnical procedure, ground freezing has been economically used as an alternative strengthening method, or as the only possible method at many sites.The frozen soil has dramatically higher strength and stiffness than the unfrozen soil.The mechanical behavior is highly dependent on the temperature below freezing point.In frozen soils, the strength and deformations are also time dependent, which means that they have clearly plastic properties that become more and more dominating when frozen temperature rises.Experience, anyhow, has showed that these characteristics allow in normal cases the engineering application of frozen ground as a temporary support in geotechnical engineering, if the specific properties and conditions are properly verified and controlled for the site.The displacements must be in given limits, and the overall safety must be high enough to maintain the continuous construction procedure until the final support has been completed. The Stranneberg tunnel was located in Sweden, at the western coast of the Gulf of Bothnia, five kilometres along the Bothniabana railway line from Örnsköldsvik towards Umeå (Figures 1 and 2).Construction planning for the freezing started in November 2001.Freezing took place in summer 2002 and excavation in the autumn of the same year.The tunnel (100 meters long, 10 meters high and 10 meters wide) required 40,000 cubic metres of soil and weak rock mass to be frozen.Freezing work on the tunnel started in early 2002 with the installation of freezing columns, and the tunnel broke through the frozen section in December 2002.VTT developed and carried out the coupled thermal and mechanical analysis and design of the tunnel, including laboratory determination of design parametres, and monitoring temperatures and displacements during the operation.Lemcon Ltd., the contractor, carried out the ground freezing, excavation, insulation, preliminary shotcreting, and cast the final liner.

AB - A new railway line was under construction in north-eastern Sweden, along the shoreline of the Gulf of Bothnia.The terrain consisted of Postglacial clay and silt valleys, and ridges of Precambrian bedrock crossed the railway line.The railway level was about 20 m below the surface of the ground.For the design of freezing, a freezing analysis was carried out to determine the pipeline depths and distances, to estimate the necessary time for freezing and to determine temperatures within the frozen zone.To estimate the deformations, displacements and safety level, a mechanical analysis of the tunnel cross-section was carried out.Time- and temperature-dependent mechanical parameters were determined for the actual soils and design temperatures.The analysis was carried out for 12 different phases during tunneling.The estimated displacements for the tunnel arch were negligible, if the temperatures were at or below -15 °C.The freezing was started in May 2002, and completed in September 2002.Tunneling was started in September, and it was completed in November 2002, following with the casting of the final liner. The application of ground freezing in deep excavations and tunnelling in soft soils is not a new idea.It has been widely discussed in ground freezing symposia since the 1970s.There are certain reasons why ground freezing has proved to be recommendable: the applications do not cause any environmental impacts on the site, freezing can be rationally planned, designed and controlled, and it uses the ground itself as a structural element.Ground freezing causes, of course, certain permanent changes to the freezing soils after thaw.Frost action causes ice segregation in the frost-susceptible soils, and results in consolidation settlements after thaw.These can be pre-estimated and evaluated in relation to neighbouring structures, if needed. As a geotechnical procedure, ground freezing has been economically used as an alternative strengthening method, or as the only possible method at many sites.The frozen soil has dramatically higher strength and stiffness than the unfrozen soil.The mechanical behavior is highly dependent on the temperature below freezing point.In frozen soils, the strength and deformations are also time dependent, which means that they have clearly plastic properties that become more and more dominating when frozen temperature rises.Experience, anyhow, has showed that these characteristics allow in normal cases the engineering application of frozen ground as a temporary support in geotechnical engineering, if the specific properties and conditions are properly verified and controlled for the site.The displacements must be in given limits, and the overall safety must be high enough to maintain the continuous construction procedure until the final support has been completed. The Stranneberg tunnel was located in Sweden, at the western coast of the Gulf of Bothnia, five kilometres along the Bothniabana railway line from Örnsköldsvik towards Umeå (Figures 1 and 2).Construction planning for the freezing started in November 2001.Freezing took place in summer 2002 and excavation in the autumn of the same year.The tunnel (100 meters long, 10 meters high and 10 meters wide) required 40,000 cubic metres of soil and weak rock mass to be frozen.Freezing work on the tunnel started in early 2002 with the installation of freezing columns, and the tunnel broke through the frozen section in December 2002.VTT developed and carried out the coupled thermal and mechanical analysis and design of the tunnel, including laboratory determination of design parametres, and monitoring temperatures and displacements during the operation.Lemcon Ltd., the contractor, carried out the ground freezing, excavation, insulation, preliminary shotcreting, and cast the final liner.

M3 - Conference article in proceedings

SN - 951-38-6311-5

T3 - VTT Symposium

SP - 245

EP - 256

BT - Applied Material Research at VTT

PB - VTT Technical Research Centre of Finland

CY - Espoo

ER -

Saarelainen S, Korkiala-Tanttu L, Kivikoski H. Railway tunneling in frozen ground on Bothniabana. In Applied Material Research at VTT: Symposium on Applied Materials. Espoo: VTT Technical Research Centre of Finland. 2006. p. 245-256. (VTT Symposium; No. 244).