Dynamic characterization of the migration of a mining pit in an alluvial channel

【摘要】 Research on in-channel sand mining is imperative as it may have a significant impact on channel morphology.Following this quest to quantitatively comprehend the phenomenon,experimental studies were done to investigate the dynamic characteristics of the migration of a mining pit.The evaluation of the migration rate of a mining pit in a physical scale model has found a rise in the migration rate of the pit’s upstream edge with increasing discharge.A wavelet analysis applied for analyzing scale-dependent migration of the bed profile of a mining pit also revealed similar findings.Additionally,the wavelet analysis examined the length-scale dependent migration of a mining pit and a decrease in the migration rate has been observed with an increase in the length scale.The plan form of a pit(length-to-width ratio)governs the erosion and deposition processes around the pit.Both physical and statistical approaches show an increase in the migration rate with an increase in the length-to-width ratio of the pit.An empirical formulation has been developed for calculating the migration rate of the upstream edge of a mining pit based on pit geometry(length-to-width ratio),average flow velocity,and critical shear stress of the bed material.The results also show a higher bed load transport rate in the channel subjected to mining as compared to a plain bed channel.更多还原

【Abstract】 Research on in-channel sand mining is imperative as it may have a significant impact on channel morphology.Following this quest to quantitatively comprehend the phenomenon,experimental studies were done to investigate the dynamic characteristics of the migration of a mining pit.The evaluation of the migration rate of a mining pit in a physical scale model has found a rise in the migration rate of the pit’s upstream edge with increasing discharge.A wavelet analysis applied for analyzing scale-dependent migration of the bed profile of a mining pit also revealed similar findings.Additionally,the wavelet analysis examined the length-scale dependent migration of a mining pit and a decrease in the migration rate has been observed with an increase in the length scale.The plan form of a pit(length-to-width ratio)governs the erosion and deposition processes around the pit.Both physical and statistical approaches show an increase in the migration rate with an increase in the length-to-width ratio of the pit.An empirical formulation has been developed for calculating the migration rate of the upstream edge of a mining pit based on pit geometry(length-to-width ratio),average flow velocity,and critical shear stress of the bed material.The results also show a higher bed load transport rate in the channel subjected to mining as compared to a plain bed channel.更多还原