Investigating the Slide Mechanism of Heap Leaching Structures Based on Physical Modeling

Abstract

In this research, first, a brief review of heap leaching structures is presented. Then, some engineering properties of natural and geo-synthetic materials of a leaching heap bed are introduced. Next, physical models of these structures are tested using a tilting table, and the apparatus's ''scale factor'' for the evaluation of the probable slides in these structures is determined. Analyses have shown that the ''scale factor'' of the ''factor of safety'' for the above physical models against slide approximately equals 1; therefore, the slide mechanism in such structures can be studied using tilting table experimental models. On this basis, 12 physical models of leaching heaps were made and their stability checked with the apparatus. Next, using Morgenstern and Price method, the stability of the above models was evaluated and the analytical and physical results were compared for the verification of the limit equilibrium approaches. Comparisons have shown that the error of such methods in the stability analyses of leaching heaps is \8 %. As a real case study, the Shahr-e-Babak heap leaching structure failure and its stabilization methods have been presented. In this project, tensile cracks occurred in the upper section of the heap after loading the second ore lift, and a part of it slid. The heap was stabilized using a double textured geo-membrane liner and safety berms.

A Systematic Review of Physical Modelling Techniques, Developments and Applications in Slope Stability Analyses

“…Table 3 Various scale factors for tilting table apparatus, Amini et al [104] No the soil slope model in a geotechnical centrifuge. The study utilised Linear Variable Differential Transducers (LVDT); three were placed at the slope's crest to capture settlement data.…”

“…Their working principle has been covered by Stimpson [125], Barton and Bandis [126] and was applied by Alejano et al [127] to estimate the shear strength of natural unfilled rough joints. Khorasani et al [14] used a tilt table apparatus initially developed by Amini et al [104] for the analysis of multi-plane and toppling failures. Amini et al [8,128] later utilised it for the physical modelling of circular and slide-toe-toppling failure modes in soil and rocks, respectively.…”

“…The slope failure is induced by increasing the plane angle to the point of model failure. Based on the design by Amini et al [104], the parts of a tiltable table include a horse, compressor, compressed air source and fitting, angular velocity control device, device to read tilt angle and transducer to record model displacements. The tilt table apparatus does not involve external loads, and the model is expected to fail under gravity.…”