Blasting vibration assessment of rock slopes and a case study

Authors: Kong, KWK Download Paper

DOI https://doi.org/10.36487/ACG_rep/1308_95_Kong

Cite As:
Kong, KWK 2013, 'Blasting vibration assessment of rock slopes and a case study', in PM Dight (ed.), Slope Stability 2013: Proceedings of the 2013 International Symposium on Slope Stability in Open Pit Mining and Civil Engineering, Australian Centre for Geomechanics, Perth, pp. 1335-1344, https://doi.org/10.36487/ACG_rep/1308_95_Kong



Abstract:
The most common types of blasting damage are caused by ground vibration. The sudden acceleration of the rock by the detonation energy acting on the drill hole generates an intense stress wave of both transverse and longitudinal wave motions in the surrounding rock. Key issues associated with the process of excavation and tunnelling include blast and, to a lesser extent, other construction vibration that affects the integrity of the surface structure and potentially slope stability. The stability of slopes subject to blasting induced ground vibration may be assessed by different approaches including the pseudo-static approach, the dynamic analysis, the empirical approach and the energy approach. For soil slope stability analysis, the Pseudo-static Approach and Dynamic Analysis are generally used. However, for rock slope stability assessment under blasting vibration effects, an energy approach is normally used. The energy approach, combined with the empirical correlation of shear strength and stiffness of rock joints developed by Barton (1990), with various joint characteristics, has been used in the analysis described in this paper. Peak particle velocity (PPV) of the potential rock block failure is a key parameter to determine the allowable charge weight per delay of the blast. Detailed discussion of the energy approach is presented in this paper and a case study illustrates the use of the method. The allowable charge weights per delay for rock blasting which may impact on the stability of slopes can be estimated using the simple energy approach. This approach can give controllable safety limits for the works. Thus, blasting works can be carried out safely with minimum to no damage or excessive ground movements to the slopes and other sensitive receivers, if the allowable PPV and charge weights are followed, and the specified monitoring works are carried out.

References: