Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Using observational method to manage safety aspects of remedial grouting of concrete dam foundations
KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Soil and Rock Mechanics.ORCID iD: 0000-0001-5372-7519
KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Soil and Rock Mechanics.ORCID iD: 0000-0002-8152-6092
Department of Civil and Environmental Engineering, Aalto University.ORCID iD: 0000-0001-9646-5029
BGC engineering Inc.ORCID iD: 0000-0002-3556-3562
2016 (English)In: Geotechnical and Geological Engineering, ISSN 0960-3182, E-ISSN 1573-1529, Vol. 34, no 5, 1613-1630 p.Article in journal (Refereed) Published
Abstract [en]

As concrete dams age, the need for remedial grouting to reduce the seepage and uplift pressure in the rock foundations under them increases. Based on a case study of a Swedish dam with very low calculated safety against sliding, this paper discusses the application of the observational method (as defined in Eurocode 7) to manage safety aspects during remedial grouting. The studied case was complex in that grouting works posed the risk of causing increased uplift pressure, which could have induced sliding failure along a shallow, persistent, horizontal rock joint in the foundation. The approach applied in the studied case mainly followed the principles of the observational method, except in some highly significant safety aspects for which alternative procedures are suggested and discussed. Implementing these procedures along with the observational method offers a coherent framework to manage the safety aspects of the remedial grouting of concrete dam foundations that is in line with modern risk-informed dam safety policies.

Place, publisher, year, edition, pages
Springer, 2016. Vol. 34, no 5, 1613-1630 p.
Keyword [en]
observational method; Eurocode 7; dam safety; foundation; grouting;
National Category
Geotechnical Engineering
Research subject
Civil and Architectural Engineering
Identifiers
URN: urn:nbn:se:kth:diva-192817DOI: 10.1007/s10706-016-0069-8ISI: 000384332200024Scopus ID: 2-s2.0-84982279542OAI: oai:DiVA.org:kth-192817DiVA: diva2:972213
Note

QC 20160929

Available from: 2016-09-20 Created: 2016-09-20 Last updated: 2017-11-21Bibliographically approved
In thesis
1. Toward a reliability framework for the observational method
Open this publication in new window or tab >>Toward a reliability framework for the observational method
2016 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Constructing sustainable structures in rock that satisfy all predefined technical specifications requires rational and effective construction methods. When the geotechnical behaviour is hard to predict, the Euro­pean design code, Eurocode 7, suggests application of the observational method to verify that the performance is acceptable. The basic principle of the method is to accept predefined changes in the design during con­struction to comply with the actual ground conditions, if the current de­sign is found unsuitable. Even though this in theory should ensure an effective design solution, formal application of the observational method is rare.

Investigating the applicability of the observational method in rock en­gineering, the aim of this thesis is to identify, highlight, and solve the aspects of the method that limit its wider application. Furthermore, the thesis aims to improve the conceptual understanding of how design deci­sions should be made when large uncertainties are present.

The main research contribution is a probabilistic framework for the observational method. The suggested methodology allows comparison of the merits of the observational method with that of conventional design. Among other things, the thesis also discusses (1) the apparent contradiction between the preference for advanced probabilistic calculation methods and sound, qualitative engineering judgement, (2) how the establishment of limit states and alarm limits must be carefully considered to ensure structural safety, and (3) the applicability of the Eurocode defini­tion of the observational method and the implications of deviations from its principles.

Abstract [sv]

För att kunna konstruera en anläggning i berg, som uppfyller satta tek­niska krav, krävs det en rationell och effektiv konstruktionsmetod. När konstruktionens beteende är svårt att förutsäga, erbjuder den europeiska standarden Eurokod 7 den så kallade observationsmetoden. Denna metod tillåter i förväg förberedda förändringar i designen under konstruktions­tiden, om observationer av konstruktionens beteende indikerar att så behövs. På så vis anpassas konstruktionen till de faktiska förhållandena i marken. Trots att detta tillvägagångssätt i teorin ger en rationell design, används metoden sällan i enlighet med Eurokod 7.

Denna doktorsavhandling undersöker tillämpbarheten av observa-tionsmetoden när man bygger i och på berg. Målet är att belysa de aspekter som begränsar dess användning och i dessa fall föreslå förbätt­ringar som ökar tillämpbarheten. I ett vidare perspektiv syftar avhand­lingen även till att förbättra den konceptuella förståelsen för hur beslut bör fattas i designprocessen när det finns stora osäkerheter.

Avhandlingen visar hur observationsmetoden kan användas i ett san­nolikhetsbaserat ramverk. Metodiken ger användaren möjlighet att jäm­föra för- och nackdelarna med observationsmetoden och konventionell dimensionering. Avhandlingen diskuterar bland annat även (1) den skenbara motsatsen mellan användandet av sannolikhetsbaserade beräkningsmetoder för att lösa komplexa dimensioneringsfrågor och kvalitativa ingenjörsmässiga bedömningar, (2) hur larmgränser och brottgränstillstånd bör definieras för att ge tillräcklig säkerhetsmarginal, samt (3) hur Eurokod 7:s strikta definition av observationsmetoden påverkar dess användbarhet.

Place, publisher, year, edition, pages
Stockholm: Kungliga Tekniska högskolan, 2016
Series
TRITA-JOB PHD, ISSN 1650-9501 ; 1023
Keyword
Rock engineering, observational method, Eurocode 7, structural safety, reliability analysis, dam safety, Bergmekanik, observationsmetoden, Eurokod 7, sannolikhetsbaserad dimensionering, dammsäkerhet
National Category
Geotechnical Engineering
Research subject
Civil and Architectural Engineering
Identifiers
urn:nbn:se:kth:diva-192825 (URN)978-91-7729-128-2 (ISBN)
Public defence
2016-10-25, F3, Lindstedtsvägen 26, Stockholm, 10:00 (English)
Opponent
Supervisors
Note

QC 20160926

Available from: 2016-09-26 Created: 2016-09-20 Last updated: 2016-09-26Bibliographically approved

Open Access in DiVA

Spross et al 2016(2109 kB)42 downloads
File information
File name FULLTEXT01.pdfFile size 2109 kBChecksum SHA-512
d4780bc7a09dae01bc9eba1e7bbfcb79ac491401f34a41c7d84ba2a1cfe92bc13279de82b5148a42ddcee43acc56d4527c11baacf61bdfd0c87d21755e394609
Type fulltextMimetype application/pdf

Other links

Publisher's full textScopusPublishers webpage

Authority records BETA

Spross, JohanJohansson, FredrikUotinen, Lauri K.T.Rafi, Jalaleddin

Search in DiVA

By author/editor
Spross, JohanJohansson, FredrikUotinen, Lauri K.T.Rafi, Jalaleddin
By organisation
Soil and Rock Mechanics
In the same journal
Geotechnical and Geological Engineering
Geotechnical Engineering

Search outside of DiVA

GoogleGoogle Scholar
Total: 42 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 201 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf