Analysis of slag debris flow initiation based on laboratory tests of slag
Abstract
Accumulated slags and waste in mines are major physical resources for slag debris flow, which is a potential major disaster threatening mines safety. Initialed by the heavy rain, slag debris flow has happened in Ganjaing gully around Luanchuan county, China. Studies have been carried out for a further undersdanding on the formation and initiation mechanism of the slag debris flow. Slag samples with different fines content are collected from the gully and the slag strength and permeability have been investgated by direct shear tests and falling head permeability tests respectively.The results indicate that the fines content has a significant impact on both the strength and permeability characteristics of slags. With the fines content increasing, both the strength and the hydraulic conductivity of the slag decrease. And the strength of saturated slag samples is extremely weak, meaning that water will easily soften the slag. In addition, as the fines content increases, the hydraulic conductivity would decrease acceleratedly to a quite small constant. Based on the current invsestgation, it can be concluded that two different types of slag debris flow would form in the specific conditions, the shallow debris flows are mainly dominated by surface erosion, while the deep debris flows by bottom tearing and suffusion erosion, respectivily.
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