Effect Of Loading Rate On Consolidation Of Hydrating Cemented Paste Backfill

M. Shahsavari, M. Jafari, M. Grabinsky

In the proceedings of: GeoEdmonton 2018: 71st Canadian Geotechnical Conference; 13th joint with IAH-CNC

Session: Mining Geotechnics and Hydrogeology III

ABSTRACT: To reduce the surface footprint of mining operations and provide support for further excavations, the mined-out voids are backfilled with mine tailings. Over the past decade cemented paste backfill has gained popularity over other backfilling materials due to its high delivery rate and tight characteristics. Fresh CPB is held in the stope by a retaining structure (i.e. barricade). Barricade is subjected to lateral stresses and pore water pressures from within the CPB. A safe and economic design of the barricade is dependent on the proper knowledge of these stresses. The pore water pressure changes due to self-weight consolidation of the hydrating CPB. One of the parameters that affect the deformations and the rate of pore water pressure generation/dissipation is the backfilling rate. In this paper the effect of backfilling rate on consolidation characteristics and deformation of fresh and cured CPB is studied. CPB Samples with 5% binder content are loaded at 5, 10, and 20 kPa/hr loading rates to represent the typical in-situ backfilling scenarios of 0.25, 0.50, and 1.0 m/hr for a CPB with a unit weight of 20 kN/m3, respectively. The deformations are recorded while samples were loaded and cured at the same time. These tests provide more information on the deformation characteristics of an accreting hydrating material and confirm the measured field void ratios at the end of the backfilling.

RÉSUMÉ: Les gradins des mines sont souvent remblayés à réduire et à permettre le support pour des excavations futures. Durant la dernière décennie le remblai à pâte cimenté (RPC) a été de plus en barricade. La barricade est soumise aux contraintes latérales et à La conception sécurisée varie en fonction de la consolidation poids propre du RPC hydratant. Un des paramètres qui influence les déformations et mûri sont interrogés. Les échantillons de RPC avec 5 pourcent contenu de liant sont chargées à 5, 10 et 20 kPa/h à mesure de simuler des scénarios typiques de livraison de RPC 0.25, 0.50 et 1.00 m/h de 20 kN/m3. Les déformations sont enregistrées durant que les échantillons ont été chargés et mûris simultanément. Ces essais ont fourni nt les taux de porosité enregistrés sur le chantier après le remblayage.

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Cite this article:
M. Shahsavari; M. Jafari; M. Grabinsky (2018) Effect Of Loading Rate On Consolidation Of Hydrating Cemented Paste Backfill in GEO2018. Ottawa, Ontario: Canadian Geotechnical Society.

@article{geo2018Paper418,author = M. Shahsavari; M. Jafari; M. Grabinsky,title = Effect Of Loading Rate On Consolidation Of Hydrating Cemented Paste Backfill,year = 2018}