Early curing age paste backfill exposures – the role of effective stress

Authors: Veenstra, RL; Grice, AG; Grabinsky, MW; Bawden, WF Download Paper

DOI https://doi.org/10.36487/ACG_rep/1504_25_Veenstra

Cite As:
Veenstra, RL, Grice, AG, Grabinsky, MW & Bawden, WF 2015, 'Early curing age paste backfill exposures – the role of effective stress', in R Jewell & AB Fourie (eds), Paste 2015: Proceedings of the 18th International Seminar on Paste and Thickened Tailings, Australian Centre for Geomechanics, Perth, pp. 329-340, https://doi.org/10.36487/ACG_rep/1504_25_Veenstra



Abstract:
This paper presents results from a numerical modelling exercise that looks at vertically exposing sub-28-day cemented paste backfill. The reason for this exercise is that underground mining operations would like to start exposing cemented paste backfill (CPB) earlier in order to increase production. However, these earlier exposures would mean that the pore water pressures in the stope may not have fully dissipated, hence entering an effective stress state versus a total stress state. The goal of this paper was to examine how effective stress impacts these early exposures. This was done by modelling the filling and the subsequent pore water dissipation within a stope. This modelled CPB was then vertically exposed, using both effective and total stress models, at various times ranging from immediately after filling to 28 days after filling. The results of these models were then compared in order to determine what difference there was between the overall outcome.

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