Method and system for measuring three-dimensional displacement

• US 5,623,108 A
• Filed: 06/07/1995
• Issued: 04/22/1997
• Est. Priority Date: 12/08/1993
• Status: Expired due to Term

• Current Assignee: National Institute of Advanced Industrial Science and Technology (Government of Japan)
• Original Assignee: Agency of Industrial Science & Technology (Government of Japan), Obayashi Corporation
• Inventors: Kosugi, Masayuki, Tamai, Akio
• Primary Examiner(s): RAEVIS, ROBERT R
• Application Number:
  US08/478,680
• Time in Patent Office: 685 Days
• Field of Search: 73/151, 73/784, 73/786, 73/865.8, 340/690, 33/DIG. 1, 33/DIG. 21, 33/544, 356/373, 324/207.23, 348/94, 348/95
• US Class Current: 73/865.8
• CPC Class Codes: E21B 47/00 Survey of boreholes or wells monitoring pressure or flow of drilling fluid E21B21/08
• CPC Class Codes: E21B 49/006 Measuring wall stresses in the borehole
• CPC Class Codes: G01B 11/16 for measuring the deformation in a solid, e.g. optical strain gauge
• CPC Class Codes: G01B 5/30 for measuring the deformation in a solid, e.g. mechanical strain gauge
• CPC Class Codes: H01L 27/14643 Photodiode arrays; MOS imagers

Abstract

A method for measuring three-dimensional displacement of a mass comprises the steps of providing a measuring object placed on the end surface of the mass, for reflecting at least a fraction of three-dimensional displacement of the mass, arranging a displacement measuring equipment for free displacement relative to the mass and in opposition to the measuring object, and measuring three-dimensional relative displacement of the mass by detecting relative displacement of sad displacement indicative means relative to the displacement measuring equipment by the latter. The method is implemented by a three-dimensional displacement measuring system comprises a measuring object placed on the end surface of the mass, for reflecting at least a fraction of three-dimensional displacement of the mass, a displacement measuring equipment arranged for free displacement relative to the mass and in opposition to the measuring object, for measuring three-dimensional relative displacement of the mass by detecting relative displacement of sad displacement indicative means relative to the displacement measuring equipment by the latter. The method and system is suitable for measuring displacement of a rock across a crack.

Claims

1. A method for measuring three-dimensional displacement of a mass, comprising the steps of:

placing a displacement indicating means on an end surface of the mass for reflecting at least a fraction of three-dimensional displacement of the mass;

arranging a displacement measuring means opposite to the displacement indicating means for free displacement relative to the mass; and

measuring relative three-dimensional displacement of the mass by detecting displacement of the displacement indicating means relative to the displacement measuring means with the displacement measuring means;

the displacement indicating means comprising a concave surface having an open end and a bottom, the concave surface comprising a curved surface converging from the open end to the bottom.

2. A method as set forth in claim 1, wherein the displacement measuring means comprises a displacement measuring apparatus arranged opposite to the concave surface and said step of measuring further comprises measuring the relative distance to the concave surface along a circumferential trace by rotating about a center axis of the concave surface while maintaining a given tilt angle relative to the center axis so as to circumferentially scan the concave surface.

3. A method as set forth in claim 2, which further comprises a step of analyzing the displacement of the circumferential trace on the concave surface that is associated with the displacement of the mass, on the basis of the relative distance measured by the displacement measuring apparatus.

4. A method as set forth in claim 3, wherein the mass comprises a first cylindrical member arranged at one side of a discontinuous surface of a bore hole, the bore hole being formed across the discontinuous surface, and the displacement measuring apparatus comprises a second cylindrical member positioned at the other side of the discontinuous surface, and said step of measuring further comprises measuring displacement of the first cylindrical member relative to the second cylindrical member across the discontinuous surface.

5. A three-dimensional displacement measuring system, comprising:

a displacement indicating means placed on an end surface of a mass for reflecting at least a fraction of three-dimensional displacement of the mass; and

a displacement measuring means, arranged for three displacement relative to the mass and opposite to the displacement indicating means, for measuring relative three-dimensional displacement of the mass by detecting displacement of said displacement indicating means relative to said displacement measuring means with said displacement measuring means;

wherein said displacement indicating means comprises a concave surface having an open end and a bottom, said concave surface comprising a curved surface converging from said open end to said bottom.

6. A system as set forth in claim 5, wherein said displacement measuring means comprises a displacement measuring apparatus arranged opposite to said concave surface for measuring the relative distance to said concave surface along a circumferential trace by rotating about a center axis of said concave surface while maintaining a given tilt angle relative to said center axis for circumferentially scanning said concave surface.

7. A system as set forth in claim 6, which further comprises means for analyzing the displacement of said circumferential trace on said concave surface that is associated with the displacement of said mass on the basis of the relative distance measured by said displacement measuring apparatus.

8. A system as set forth in claim 7, wherein said displacement measuring apparatus comprises non-contact measuring equipment that does not contact said concave surface in operation.

9. A system as set forth in claim 8, wherein said non-contact measuring equipment comprises a laser displacement gauge for radiating a laser beam obliquely to the center axis of said concave surface.

10. A system as set forth in claim 9, wherein said displacement measuring apparatus comprises a rotary table having a rotary shaft in alignment with the center axis of said concave surface, said rotary table being driven by a motor, and said laser displacement gauge being mounted on said rotary table.

11. A system as set forth in claim 8, wherein said mass comprises a first cylindrical member arranged at one side of a discontinuous surface in a bore hole, the bore hole being formed across the discontinuous surface, and said displacement measuring apparatus comprising a second cylindrical member positioned at the other side of said discontinuous surface.

12. A system as set forth in claim 11, wherein said first and second cylindrical members each comprises supporting legs and fixing rods that are adapted to be press fitted to the inner periphery of the bore hole.