### Abstract

Discontinuity data of a 400 m tunnel located close to the proposed shiplock area were investigated to characterize the discontinuity geometry of the rock mass around the tunnel. Traces of 39 major discontinuities (faults and dykes) were found on the tunnel exposures. Over 2000 minor discontinuity (joint) trace data available showed that the rock mass can be separated into about 5 statistically homogeneous regions. Three to four joint sets were found to exist in each of these regions. Available theoretical probability distributions were found to be insufficient to represent the statistical distribution of orientation of joint clusters. For more than 94% of the joint sets, gamma distribution was found to be the best probability distribution for representing a joint size distribution. Exponential and gamma distributions turned out to be the best probability distributions for representing joint spacing distributions for the joint data studied here. Too many censored joint trace data showed a very significant effect of the trace length biases on the estimated mean trace length. This indicated that the 2 m wide exposures which were used for collecting the joint trace data are not sufficient to produce reliable estimates for joint size parameters for the Shiplock area To obtain better estimates, it is necessary to collect joint data for several exposures which are at least 4-5 m wide and have different orientations. When such data become available for the Three Gorges region, validation studies should be performed to check the applicability of the built-up models, in addition to performing the modelling. Rock Mechanics, Daemen & Schultz (eds).

Original language | English (US) |
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Title of host publication | 35th U.S. Symposium on Rock Mechanics, USRMS 1995 |

Editors | Daemen, Schultz |

Publisher | American Rock Mechanics Association (ARMA) |

Pages | 807-812 |

Number of pages | 6 |

ISBN (Print) | 9054105526, 9789054105527 |

State | Published - Jan 1 1995 |

Event | 35th U.S. Symposium on Rock Mechanics, USRMS 1995 - Reno, United States Duration: Jun 5 1995 → Jun 7 1995 |

### Other

Other | 35th U.S. Symposium on Rock Mechanics, USRMS 1995 |
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Country | United States |

City | Reno |

Period | 6/5/95 → 6/7/95 |

### Fingerprint

### ASJC Scopus subject areas

- Geophysics
- Geochemistry and Petrology

### Cite this

*35th U.S. Symposium on Rock Mechanics, USRMS 1995*(pp. 807-812). American Rock Mechanics Association (ARMA).

**Discontinuity network modeling of the rock mass around a tunnel close to the proposed permanent shiplock area of the three gorges dam site in China.** / Kulatilake, Pinnaduwa; Chen, Jianping; Teng, Jianren; Pan, Gang; Shufang, Xiao.

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

*35th U.S. Symposium on Rock Mechanics, USRMS 1995.*American Rock Mechanics Association (ARMA), pp. 807-812, 35th U.S. Symposium on Rock Mechanics, USRMS 1995, Reno, United States, 6/5/95.

}

TY - GEN

T1 - Discontinuity network modeling of the rock mass around a tunnel close to the proposed permanent shiplock area of the three gorges dam site in China

AU - Kulatilake, Pinnaduwa

AU - Chen, Jianping

AU - Teng, Jianren

AU - Pan, Gang

AU - Shufang, Xiao

PY - 1995/1/1

Y1 - 1995/1/1

N2 - Discontinuity data of a 400 m tunnel located close to the proposed shiplock area were investigated to characterize the discontinuity geometry of the rock mass around the tunnel. Traces of 39 major discontinuities (faults and dykes) were found on the tunnel exposures. Over 2000 minor discontinuity (joint) trace data available showed that the rock mass can be separated into about 5 statistically homogeneous regions. Three to four joint sets were found to exist in each of these regions. Available theoretical probability distributions were found to be insufficient to represent the statistical distribution of orientation of joint clusters. For more than 94% of the joint sets, gamma distribution was found to be the best probability distribution for representing a joint size distribution. Exponential and gamma distributions turned out to be the best probability distributions for representing joint spacing distributions for the joint data studied here. Too many censored joint trace data showed a very significant effect of the trace length biases on the estimated mean trace length. This indicated that the 2 m wide exposures which were used for collecting the joint trace data are not sufficient to produce reliable estimates for joint size parameters for the Shiplock area To obtain better estimates, it is necessary to collect joint data for several exposures which are at least 4-5 m wide and have different orientations. When such data become available for the Three Gorges region, validation studies should be performed to check the applicability of the built-up models, in addition to performing the modelling. Rock Mechanics, Daemen & Schultz (eds).

AB - Discontinuity data of a 400 m tunnel located close to the proposed shiplock area were investigated to characterize the discontinuity geometry of the rock mass around the tunnel. Traces of 39 major discontinuities (faults and dykes) were found on the tunnel exposures. Over 2000 minor discontinuity (joint) trace data available showed that the rock mass can be separated into about 5 statistically homogeneous regions. Three to four joint sets were found to exist in each of these regions. Available theoretical probability distributions were found to be insufficient to represent the statistical distribution of orientation of joint clusters. For more than 94% of the joint sets, gamma distribution was found to be the best probability distribution for representing a joint size distribution. Exponential and gamma distributions turned out to be the best probability distributions for representing joint spacing distributions for the joint data studied here. Too many censored joint trace data showed a very significant effect of the trace length biases on the estimated mean trace length. This indicated that the 2 m wide exposures which were used for collecting the joint trace data are not sufficient to produce reliable estimates for joint size parameters for the Shiplock area To obtain better estimates, it is necessary to collect joint data for several exposures which are at least 4-5 m wide and have different orientations. When such data become available for the Three Gorges region, validation studies should be performed to check the applicability of the built-up models, in addition to performing the modelling. Rock Mechanics, Daemen & Schultz (eds).

UR - http://www.scopus.com/inward/record.url?scp=60649114990&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=60649114990&partnerID=8YFLogxK

M3 - Conference contribution

SN - 9054105526

SN - 9789054105527

SP - 807

EP - 812

BT - 35th U.S. Symposium on Rock Mechanics, USRMS 1995

A2 - Daemen, null

A2 - Schultz, null

PB - American Rock Mechanics Association (ARMA)

ER -