### Abstract

This paper describes the development of a new test for measuring the mode II fracture toughness for rock, K_{IIC}. The test is called the Modified Punch Through Shear test (MPTS), which is a modification of the PTS test developed by [4]. Laboratory MPTS tests on Columbia granite were conducted. The lab tests and finite element modeling reveal that a valid shear crack is produced. Tests conducted at different confining stresses show that the shear cracking strength is a function of confining stress. Tests at each confinement were repeated 7 times, and even though the scatter in the results is large, best-fit results for shear cracking strength as a function of confining stress were determined. PFC modeling has also been conducted to simulate in detail the development of tensile and shear cracks in the MPTS test. A clump model rather than the standard Circular Particle Interaction (CPI) model was used to improve the strength envelope.

Original language | English (US) |
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Title of host publication | Proceedings of the 41st U.S. Rock Mechanics Symposium - ARMA's Golden Rocks 2006 - 50 Years of Rock Mechanics |

State | Published - 2006 |

Event | 41st U.S. Rock Mechanics Symposium - ARMA's Golden Rocks 2006 - 50 Years of Rock Mechanics - Golden, CO, United States Duration: Jun 17 2006 → Jun 21 2006 |

### Other

Other | 41st U.S. Rock Mechanics Symposium - ARMA's Golden Rocks 2006 - 50 Years of Rock Mechanics |
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Country | United States |

City | Golden, CO |

Period | 6/17/06 → 6/21/06 |

### Fingerprint

### ASJC Scopus subject areas

- Geochemistry and Petrology
- Geophysics

### Cite this

*Proceedings of the 41st U.S. Rock Mechanics Symposium - ARMA's Golden Rocks 2006 - 50 Years of Rock Mechanics*

**Modified PTS test and clump modeling on mixed mode crack growth in granite.** / Lee, J. S.; Kemeny, John M; Ko, T. Y.

Research output: Chapter in Book/Report/Conference proceeding › Conference contribution

*Proceedings of the 41st U.S. Rock Mechanics Symposium - ARMA's Golden Rocks 2006 - 50 Years of Rock Mechanics.*41st U.S. Rock Mechanics Symposium - ARMA's Golden Rocks 2006 - 50 Years of Rock Mechanics, Golden, CO, United States, 6/17/06.

}

TY - GEN

T1 - Modified PTS test and clump modeling on mixed mode crack growth in granite

AU - Lee, J. S.

AU - Kemeny, John M

AU - Ko, T. Y.

PY - 2006

Y1 - 2006

N2 - This paper describes the development of a new test for measuring the mode II fracture toughness for rock, KIIC. The test is called the Modified Punch Through Shear test (MPTS), which is a modification of the PTS test developed by [4]. Laboratory MPTS tests on Columbia granite were conducted. The lab tests and finite element modeling reveal that a valid shear crack is produced. Tests conducted at different confining stresses show that the shear cracking strength is a function of confining stress. Tests at each confinement were repeated 7 times, and even though the scatter in the results is large, best-fit results for shear cracking strength as a function of confining stress were determined. PFC modeling has also been conducted to simulate in detail the development of tensile and shear cracks in the MPTS test. A clump model rather than the standard Circular Particle Interaction (CPI) model was used to improve the strength envelope.

AB - This paper describes the development of a new test for measuring the mode II fracture toughness for rock, KIIC. The test is called the Modified Punch Through Shear test (MPTS), which is a modification of the PTS test developed by [4]. Laboratory MPTS tests on Columbia granite were conducted. The lab tests and finite element modeling reveal that a valid shear crack is produced. Tests conducted at different confining stresses show that the shear cracking strength is a function of confining stress. Tests at each confinement were repeated 7 times, and even though the scatter in the results is large, best-fit results for shear cracking strength as a function of confining stress were determined. PFC modeling has also been conducted to simulate in detail the development of tensile and shear cracks in the MPTS test. A clump model rather than the standard Circular Particle Interaction (CPI) model was used to improve the strength envelope.

UR - http://www.scopus.com/inward/record.url?scp=69149092922&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=69149092922&partnerID=8YFLogxK

M3 - Conference contribution

AN - SCOPUS:69149092922

BT - Proceedings of the 41st U.S. Rock Mechanics Symposium - ARMA's Golden Rocks 2006 - 50 Years of Rock Mechanics

ER -