Surveying at Oyu Tolgoi Copper/Gold Mine - Chris Hutchison - AIMS

More documents

Recommendations

Info

CONCLUSION (cont) At the 1300 level, the mine coordinate join near the shaft differed by 6 seconds (higher) than the gyro bearing. This shows a good comparison between the German gyro controlled coordinates of the wall stations at that level. The angular misclose in our traverse at 1300 level compared to the initial gyro showed only 11 arc seconds and, at the 512 level, the difference between the gyro orientations was 4 arc seconds. After adjustment of our traverse for the angular miscloses revealed by the gyro orientations and using the coordinates we transferred to the surface and into the mine, the new coordinate joins differed from the gyro bearing as follows: ‐ Surface calibration baseline coordinate grid ±0.0 seconds to gyro (datum line) ‐ Surface raise bore baseline coordinate grid ‐0.2 seconds equals gyro ‐ 512 level (shaft) coordinate grid +1.4 arc seconds equals gyro ‐ 512 level (raise bore) coordinate grid +1.0 arc seconds equals gyro ‐ 1300 level (shaft) coordinate grid ‐0.7arc seconds equals gyro ‐ 1300 level (inbye traverse end) coordinate grid +0.3 arc seconds equals gyro
CONCLUSION (cont) The raise bore positions at surface, 512 level and 1300 level are affected by the combined projection and height scale factors at their levels. The projection scale factor is a constant but, because of the mine location in the zone and the latitude of the mine, the height scale factor varied by about 200 mm per kilometre between the surface and the 1300 level. This fact is further complicated by the local Mine Surveyors not using either a projection or height scale factor in their traverses and the principal’s requirements that we provide plane rectangular (mine grid) coordinates for survey stations (including the raise bore sites) at each level. This led to there being a different local coordinate at each mine level for the raise bore site to maintain a truly vertical shaft hftowards the centre of the earth.
Page 1 and 2: SURVEYING AT OYU TOLGOI COPPER/GOLD
Page 3 and 4: OWNERSHIP & HISTORY (cont) • The
Page 5 and 6: GEOLOGY The South Gobi area lies ne
Page 7 and 8: SITE CONDITIONS Temperature at the
Page 9 and 10: SITE CONDITIONS (cont) Transport to
Page 11 and 12: SITE CONDITIONS (cont) Mongolia has
Page 13 and 14: PROJECT REQUIREMENTS AND PROJECT TE
Page 15 and 16: TECHNICAL SOLUTIONS • Due to the
Page 17 and 18: TECHNICAL SOLUTIONS (cont) • A Ge
Page 19 and 20: TECHNICAL SOLUTIONS (cont) • Rath
Page 21 and 22: TECHNICAL SOLUTIONS (cont) • Conn
Page 23: CONCLUSION (cont) • Our GAK1 gyro
Page 27 and 28: Acknowledgements • Thanks are due

Surveying at Oyu Tolgoi Copper/Gold Mine - Chris Hutchison - AIMS

Create successful ePaper yourself

Delete template?

Save as template?