Estimation of deformation and stiffness of fractures close to tunnels using data from single-hole hydraulic testing and grouting

PDF Version Also Available for Download.

Description

Sealing of tunnels in fractured rocks is commonly performed by pre- or post-excavation grouting. The grouting boreholes are frequently drilled close to the tunnel wall, an area where rock stresses can be low and fractures can more easily open up during grout pressurization. In this paper we suggest that data from hydraulic testing and grouting can be used to identify grout-induced fracture opening, to estimate fracture stiffness of such fractures, and to evaluate its impact on the grout performance. A conceptual model and a method are presented for estimating fracture stiffness. The method is demonstrated using grouting data from four ... continued below

Physical Description

887

Creation Information

Fransson, A.; Tsang, C.-F.; Rutqvist, J. & Gustafson, G. May 1, 2010.

Context

This article is part of the collection entitled: Office of Scientific & Technical Information Technical Reports and was provided by UNT Libraries Government Documents Department to Digital Library, a digital repository hosted by the UNT Libraries. More information about this article can be viewed below.

Who

People and organizations associated with either the creation of this article or its content.

Publisher

Provided By

UNT Libraries Government Documents Department

Serving as both a federal and a state depository library, the UNT Libraries Government Documents Department maintains millions of items in a variety of formats. The department is a member of the FDLP Content Partnerships Program and an Affiliated Archive of the National Archives.

Contact Us

What

Descriptive information to help identify this article. Follow the links below to find similar items on the Digital Library.

Description

Sealing of tunnels in fractured rocks is commonly performed by pre- or post-excavation grouting. The grouting boreholes are frequently drilled close to the tunnel wall, an area where rock stresses can be low and fractures can more easily open up during grout pressurization. In this paper we suggest that data from hydraulic testing and grouting can be used to identify grout-induced fracture opening, to estimate fracture stiffness of such fractures, and to evaluate its impact on the grout performance. A conceptual model and a method are presented for estimating fracture stiffness. The method is demonstrated using grouting data from four pre-excavation grouting boreholes at a shallow tunnel (50 m) in Nygard, Sweden, and two post-excavation grouting boreholes at a deep tunnel (450 m) in Aespoe HRL, Sweden. The estimated stiffness of intersecting fractures for the boreholes at the shallow Nygard tunnel are low (2-5 GPa/m) and in agreement with literature data from field experiments at other fractured rock sites. Higher stiffness was obtained for the deeper tunnel boreholes at Aespoe which is reasonable considering that generally higher rock stresses are expected at greater depths. Our method of identifying and evaluating the properties and impact of deforming fractures might be most applicable when grouting takes place in boreholes adjacent to the tunnel wall, where local stresses might be low and where deforming (opening) fractures may take most of the grout.

Physical Description

887

Source

  • Journal Name: International Journal of Rock Mechanics and Mining Sciences; Journal Volume: 47; Journal Issue: 6; Related Information: Journal Publication Date: 2010

Language

Item Type

Identifier

Unique identifying numbers for this article in the Digital Library or other systems.

  • Report No.: LBNL-3590E
  • Grant Number: DE-AC02-05CH11231
  • DOI: 10.1016/j.ijrmms.2010.05.007 | External Link
  • Office of Scientific & Technical Information Report Number: 989846
  • Archival Resource Key: ark:/67531/metadc1012277

Collections

This article is part of the following collection of related materials.

Office of Scientific & Technical Information Technical Reports

Reports, articles and other documents harvested from the Office of Scientific and Technical Information.

Office of Scientific and Technical Information (OSTI) is the Department of Energy (DOE) office that collects, preserves, and disseminates DOE-sponsored research and development (R&D) results that are the outcomes of R&D projects or other funded activities at DOE labs and facilities nationwide and grantees at universities and other institutions.

What responsibilities do I have when using this article?

When

Dates and time periods associated with this article.

Creation Date

  • May 1, 2010

Added to The UNT Digital Library

  • Oct. 14, 2017, 8:36 a.m.

Description Last Updated

  • Oct. 17, 2017, 8:14 p.m.

Usage Statistics

When was this article last used?

Yesterday: 0
Past 30 days: 0
Total Uses: 1

Interact With This Article

Here are some suggestions for what to do next.

Start Reading

PDF Version Also Available for Download.

Citations, Rights, Re-Use

Fransson, A.; Tsang, C.-F.; Rutqvist, J. & Gustafson, G. Estimation of deformation and stiffness of fractures close to tunnels using data from single-hole hydraulic testing and grouting, article, May 1, 2010; Berkeley, California. (digital.library.unt.edu/ark:/67531/metadc1012277/: accessed May 21, 2018), University of North Texas Libraries, Digital Library, digital.library.unt.edu; crediting UNT Libraries Government Documents Department.