Collapse settlement of dump soils revealed by studies on soil samples of modelled lithology and lump-size distribution

Abstract

The pa per deals with the col lapse set tle ment of dump soils i.e., made grounds com posed of the over bur den soils of min eral de pos its, which were worked out with the open-pit method, trans ported and de pos ited as a dumped fill. The prin ci pal aim of the stud ies was the anal y sis of fac tors con trol ling the col lapse set tle ment pro cess, mostly the struc tural model of dump soil and ex ter nal de ter mi nants: ini tial com pac tion, ini tial wa ter con tent and his tory of its changes in time as well as the his tory of load ing of stud ied soil be fore sat u ra tion. In or der to re flect the nat u ral struc ture of dump soils, ex per i ments were car ried out on sam ples of spe cially mod elled li thol ogy and struc ture. Hence, the sam ples rep re sented three ba sic struc tural mod els of such soils: non-co he sive, co he sive and tran si tional, partly co he sive/partly non-co he sive. At ten tion was paid to di ver si fied dy nam ics of col lapse set tle ment, which re sults from two clearly dif fer ent pro cesses: re build ing of soil struc ture and ad di tional con sol i da tion set tle ment. It was found that from the phys i cal point of view the col lapse set tle ment re sults from the re lease of elas tic en ergy de liv ered to the sam ple by load ing be fore in un da tion and ac cu mu lated at the con tact sur faces of soil lumps.