## Abstract

We investigate the feasibility of estimating an in situ three-dimensional stress field by using data of drilling-induced tensile fractures (DTFs) observed in a single borehole. The principal assumptions in this investigation are that the rock is isotropic, homogeneous and elastic. A DTF is a longitudinal crack consisting of many small parallel cracks which are oblique to the borehole axis. A DTF is characterized by its circumferential position (θ_{mD}) along the borehole surface and the inclination (γ_{m}) of the small cracks with respect to the borehole axis. We show how it is possible to estimate the three-dimensional stress field by using the variation of Θ_{mD} and γ_{m} with respect to borehole orientation (i.e. azimuth and inclination of a borehole). Based on the variation of Θ_{mD} and γ_{m} as functions of borehole orientation which changes with depth, an inverse problem is formulated to estimate the three-dimensional stress field. Tests with synthetic data sets (Θ_{mD} and γ_{m}) show that it is feasible to estimate the three-dimensional stress field and that the statistical approach is appropriate for the inversion practically. Finally, we discuss a DTF data set (Θ_{mD} and γ_{m}) measured in a real borehole in the northern area of Japan Main Island and apply the inversion technique to estimate the stress field.

Original language | English |
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Pages (from-to) | 747-758 |

Number of pages | 12 |

Journal | International Journal of Rock Mechanics and Mining Sciences |

Volume | 35 |

Issue number | 6 |

DOIs | |

Publication status | Published - 1998 Jan 1 |

## ASJC Scopus subject areas

- Geotechnical Engineering and Engineering Geology