Mechanized Clearing of Debris-Flow Deposits with Coarse-Fraction Separation for Road Construction

Abstract

This study investigates a technology for the mechanized clearing of debris-flow deposits with simultaneous separation of coarse mineral material directly within an excavator working attachment. A modified bucket with a replaceable grated bottom is proposed to separate the debris-flow mass into a coarse mineral fraction and a fine clay-dust component. Based on granulometric analysis, discrete element method (DEM) simulations, and a computational assessment of productivity, the influence of grate opening size on separation efficiency and grate clogging was investigated. For the studied particle-size distribution, a rational grate opening range of 50-70 mm was identified. The fraction of particles larger than 10 mm accounted for 48.1% of the adopted model composition, indicating a substantial potential for subsequent use of the separated mineral material in road construction, subject to verification of its physical and mechanical properties. The computational assessment indicates that separating the fine fraction can reduce the volume of material requiring transportation by approximately 40-60%. For a reference debris-flow deposit volume of 10,000 m³, the estimated economic effect was approximately KZT 45.5 million. The proposed technology integrates clearing, preliminary classification, and preparation of coarse mineral material within a single mechanized operation, potentially reducing the volume of debris-flow material requiring disposal and the demand for transported natural aggregates.