Abstract
Precise evaluation of the permeability in a dam foundation is extremely important for reasonable dam foundation treatment. The Lugeon test of permeability assumes a laminar flow around a test section in a test hole. However, it is often pointed that the flow around the section is usually a turbulent flow. In such cases, the permeability is underestimated. To investigate this matter further, laboratory tests of permeability were conducted on single cracks of boring cores. In this experiment, water was used to evaluate the transfer condition from a laminar flow to a turbulent flow. Results show that the critical Reynolds numbers were on the order of several hundreds, which is much lower than the standard number of 2,000 for the flow between a pair of parallel plates. Subsequently, the progressive conditions of the turbulent flow in the Lugeon tests were evaluated using a new theoretical equation representing the relation between the injection pressure and flow rate under laminar and turbulent conditions on a radial flow model between parallel plates. The outcome indicated that the turbulent flow was highly developed in the tests. Based on the results presented above, the flow condition in a rock mass during grouting was evaluated. The evaluation model was the previous model expanded for use with non-Newtonian fluids. Using this model, a new injection method was proposed for grout particles to penetrate to the target area, and then subsequently settle and block up cracks from the far side toward the near side around a borehole. Using this method, the grout-flow condition is kept turbulent with high carrying power in the interval of penetration to the target area. Then the condition becomes laminar for settlement. The feasibility of this method was evaluated using results of calculations done with the model.
| Original language | English |
|---|---|
| Title of host publication | ISRM International Symposium - 8th Asian Rock Mechanics Symposium, ARMS 2014 |
| Publisher | International Society for Rock Mechanics |
| Pages | 2661-2670 |
| Number of pages | 10 |
| ISBN (Print) | 9784907430030 |
| Publication status | Published - 2014 |
| Event | 8th Asian Rock Mechanics Symposium, ARMS 2014 - Sapporo, Japan Duration: 2014 Oct 14 → 2014 Oct 16 |
Other
| Other | 8th Asian Rock Mechanics Symposium, ARMS 2014 |
|---|---|
| Country | Japan |
| City | Sapporo |
| Period | 14/10/14 → 14/10/16 |
Fingerprint
Keywords
- Grouting
- Laminar and turbulent flow
- Permeability
- Reynolds number
ASJC Scopus subject areas
- Geophysics
- Geochemistry and Petrology
Cite this
Evaluation of turbulent flow conditions in rock cracks and feasibility of a new grouting method for laminar and turbulent conditions. / Kishi, H.; Kakue, T.; Komine, Hideo; Murakami, S.
ISRM International Symposium - 8th Asian Rock Mechanics Symposium, ARMS 2014. International Society for Rock Mechanics, 2014. p. 2661-2670.Research output: Chapter in Book/Report/Conference proceeding › Conference contribution
}
TY - GEN
T1 - Evaluation of turbulent flow conditions in rock cracks and feasibility of a new grouting method for laminar and turbulent conditions
AU - Kishi, H.
AU - Kakue, T.
AU - Komine, Hideo
AU - Murakami, S.
PY - 2014
Y1 - 2014
N2 - Precise evaluation of the permeability in a dam foundation is extremely important for reasonable dam foundation treatment. The Lugeon test of permeability assumes a laminar flow around a test section in a test hole. However, it is often pointed that the flow around the section is usually a turbulent flow. In such cases, the permeability is underestimated. To investigate this matter further, laboratory tests of permeability were conducted on single cracks of boring cores. In this experiment, water was used to evaluate the transfer condition from a laminar flow to a turbulent flow. Results show that the critical Reynolds numbers were on the order of several hundreds, which is much lower than the standard number of 2,000 for the flow between a pair of parallel plates. Subsequently, the progressive conditions of the turbulent flow in the Lugeon tests were evaluated using a new theoretical equation representing the relation between the injection pressure and flow rate under laminar and turbulent conditions on a radial flow model between parallel plates. The outcome indicated that the turbulent flow was highly developed in the tests. Based on the results presented above, the flow condition in a rock mass during grouting was evaluated. The evaluation model was the previous model expanded for use with non-Newtonian fluids. Using this model, a new injection method was proposed for grout particles to penetrate to the target area, and then subsequently settle and block up cracks from the far side toward the near side around a borehole. Using this method, the grout-flow condition is kept turbulent with high carrying power in the interval of penetration to the target area. Then the condition becomes laminar for settlement. The feasibility of this method was evaluated using results of calculations done with the model.
AB - Precise evaluation of the permeability in a dam foundation is extremely important for reasonable dam foundation treatment. The Lugeon test of permeability assumes a laminar flow around a test section in a test hole. However, it is often pointed that the flow around the section is usually a turbulent flow. In such cases, the permeability is underestimated. To investigate this matter further, laboratory tests of permeability were conducted on single cracks of boring cores. In this experiment, water was used to evaluate the transfer condition from a laminar flow to a turbulent flow. Results show that the critical Reynolds numbers were on the order of several hundreds, which is much lower than the standard number of 2,000 for the flow between a pair of parallel plates. Subsequently, the progressive conditions of the turbulent flow in the Lugeon tests were evaluated using a new theoretical equation representing the relation between the injection pressure and flow rate under laminar and turbulent conditions on a radial flow model between parallel plates. The outcome indicated that the turbulent flow was highly developed in the tests. Based on the results presented above, the flow condition in a rock mass during grouting was evaluated. The evaluation model was the previous model expanded for use with non-Newtonian fluids. Using this model, a new injection method was proposed for grout particles to penetrate to the target area, and then subsequently settle and block up cracks from the far side toward the near side around a borehole. Using this method, the grout-flow condition is kept turbulent with high carrying power in the interval of penetration to the target area. Then the condition becomes laminar for settlement. The feasibility of this method was evaluated using results of calculations done with the model.
KW - Grouting
KW - Laminar and turbulent flow
KW - Permeability
KW - Reynolds number
UR - http://www.scopus.com/inward/record.url?scp=84962385245&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84962385245&partnerID=8YFLogxK
M3 - Conference contribution
AN - SCOPUS:84962385245
SN - 9784907430030
SP - 2661
EP - 2670
BT - ISRM International Symposium - 8th Asian Rock Mechanics Symposium, ARMS 2014
PB - International Society for Rock Mechanics
ER -