Partial reactivation of a DGSD of ignimbrite and tuff in an alpine glacial valley in Northern Italy

This paper describes the surveys, site investigations, field measurements and laboratory tests carried out to analyze the stability of a slope in the Isarco alpine glacial valley, in Northern Italy, where rocks and debris of ignimbrite and tuff outcrop. This valley is crossed by the major transport infrastructures connecting Italy to the central Europe: SS12 State Road,A22 (E45) Motorway, Verona-Brennero railway, high-speed railway network TNT-T5. Recently, large deformations of the pads of a viaduct were identified and were supposed to be caused by the downslope movement of the piers. In effect, subsequent investigations and measurements revealed the existence of sliding surfaces with movements smaller than 1 cm per year. Surveys identified that movements occur at the toe of a DGSD and back-analyses revealed that the residual shear strength estimated with shearbox tests is mobilized on the sliding surfaces

A new concept of backfill design—Application of wick drains in backfilled stopes

Backfilling represents an environmentally friendly mining waste disposal technique. It is increasingly used in underground mines all over the world. However, its primary purpose remains to improve ground stability and to reduce ore dilution. Previous investigations have shown that fill drainage plays a key role in backfill and barricade design. With a poor drainage system in the backfilled stope, the required dimension of barricade, which is constructed at the base of the stope near the drift entrance, has to be increased. A poor backfill drainage system can also lead to a significant increase in drainage waiting time and further reduction in mining productivity. In this paper, the drainage of conventional backfill design in backfilled stopes is briefly reviewed. For the first time, the application of the wick drain is introduced in the backfill within mine stopes. The drainage improvement from the introduction of the wick drain is illustrated using numerical modeling. Keywords: Mines, Backfill, Backfilled stopes, Drainage, Wick drain