OceanaGold Waihi North Project Vibration Performance Assessment Page 9 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 Whilst amenity-based limits are generally stated as a simple single value, frequency-based limits are better linked to structure response. The recommended limits in standards generally relate to the prevention of threshold cosmetic damage in the most susceptible of materials of the structure such as plaster and low-density building materials. Other materials including masonry, concrete block and mass concrete can withstand much higher levels of vibration without damage. An amenity-based vibration level applied to commercial buildings is typically less restrictive than that for residential properties. Where an alternative value is applied, a limit twice that of the residential value is common. Whilst countries like Australia and New Zealand apply vibration criteria for residential properties that are based solely on protection of amenity, some countries, like the USA, apply permissible values that eliminate structural damage without any consideration of personal amenity. It is common for the vibration conditions to be expressed either as a percentile value, such as 90% or 95% compliance, or as a relative number of successive blasts complying with a vibration value, e.g. 4 from 5 or 9 from 10 blasts. The percentile application of a vibration limit is to account for those unknown and varying influence factors, not to account for poor performance in designing and implementing blasting, and never to allow for a blast pattern designed to knowingly exceed the permissible vibration criteria. 6.1. Hauraki District Plan Section 8.3.2.1 of the Operative Hauraki District Plan provides commentary on the effects of ground vibration, how it may affect structures or personal amenity, and a series of permissible levels for different activities. Section 8.3.2.1 states: (1) Introduction – a. Ground vibration from land use activities can range in effect from structural damage to buildings (relatively extreme level of vibration) to disturbance of sleep and reduction of amenity as a result of people being able to perceive vibration. It is considered that ground vibration standards should be set in terms of human perception rather than in relation to the structural implications for buildings, thus ensuring that the amenity values of any area are not unreasonably compromised. b. Measurement of vibration is taken in the ground rather than in affected buildings, as buildings respond differently and thus the vibration response in the building may amplify ground vibration. It is beyond the scope of this standard to define that response. (2) Types of Ground Vibration a. Ground vibration may be continuous or transient, with transient vibration being either impulsive or intermittent vibration. b. Continuous vibration is vibration that remains uninterrupted over a given time period, typically a period of several minutes or more (e.g. vibration generated by construction equipment such as impact and vibratory rollers). c. Impulsive vibration is a short duration event, that involves the rapid build-up of vibration then decay, that may comprise a single pulse or a number of pulses (e.g. vibration generated by blasting) d. Intermittent vibration is a string of vibration incidents, each of short duration and separated by intervals of a much lower vibration magnitude e. Acceptable levels for continuous vibration are considerably less than those for transient vibration. (4) Transient Vibration2 2 Section (3) entitled Continuous Vibration has not been included in this report because of its irrelevance
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