OceanaGold Waihi North Project Vibration Performance Assessment Page 30 of 41 Project Number: HP2006-2 Heilig & Partners Save Date: 21/06/2022 5:55:00 PM ABN 56 082 976 714 File Name: WAI-985-000-REP-LC-0018_Rev 0 Figure 11 – OceanaGold’s web page showing measured vibration levels for each monitoring site 15.1. WUG Vibration Monitoring Vibration monitoring for blasting in WUG is proposed to avoid potential effects on Archey’s frogs. Monitoring the level of vibration at WUG is complicated by access requirements through the heavily vegetated terrain above the orebodies. Experience at other monitoring sites around Waihi have also shown that the movement of trees in windy conditions can lead vibration that routinely exceeds the vibration threshold level. The monitoring equipment requires either access to 240V power or 12V solar which necessitates consistent and unimpeded access to the sun. Given that 240V power will not be readily accessible at the surface above the mine, and the effectiveness of solar panels may be limited because of the heavy vegetation, an alternative monitoring approach is proposed. The proposed method for monitoring the vibration from the WUG blasting activities will include measuring vibration at selected locations within the underground mine and adjusting the level to reflect the value that would have been measured at the surface. These values will be compared to the permissible criterion. It is proposed to use the same monitoring equipment and assessment software that have been successfully used for previous of blast monitoring at the various Waihi orebodies, including the predictive modules used for the Amenity Effect Programme (AEP) calculations. It is proposed that vibration levels will be monitored from sensors placed within holes drilled from the upper levels of the underground mine development. Using algorithms consistent with those currently used for the AEP calculations, the level of vibration at representative locations on the surface will be extrapolated from the measured underground results. The approach mirrors the current monitoring arrangement at Waihi where vibration levels are measured at multiple locations and these data are used in determining the vibration that would have occurred at other properties around the mine. This approach of using the AEP algorithm allows prediction of vibration at many more locations than where the vibration has been directly measured. An example of the underground locations is shown in the following sketch.
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