Findings of International Review of Soil Cover Design and Construction Practices for Mine Waste Closure

2006 ◽  
Vol 2006 (2) ◽  
pp. 1804-1822
Author(s):  
M. Rykaart ◽  
D. Hockley ◽  
M. Noel ◽  
M. Paul
Keyword(s):  
Soil Cover ◽  
Mine Waste ◽  
International Review ◽  
Cover Design ◽  
Design And Construction

Variations in moisture content for a soil cover over a 10 year period

2005 ◽  
Vol 42 (6) ◽  
pp. 1615-1630 ◽  
Author(s):  
Björn Weeks ◽  
G Ward Wilson
Keyword(s):  
Moisture Content ◽  
Soil Cover ◽  
Acid Rock Drainage ◽  
Lower Layer ◽  
Mine Waste ◽  
Waste Rock ◽  
Weather Data ◽  
Moisture Profile ◽  
Acid Rock ◽  
Cover Design

The Equity Silver mine is located in north-central British Columbia and is the site of a large, well-instrumented soil cover. The soil-cover site was designed to prevent the generation of acid rock drainage from the acid-generating waste rock disposed of at this site. The cover was designed to act as an oxygen barrier by maintaining a layer of saturated soil above the waste rock. The cover consists of a compacted till placed over the waste rock and covered with a non-compacted layer of the same material. Neutron probes and thermal conductivity sensors were used to monitor the moisture content of the cover soil over a 10 year period. Weather data at the site were also collected. A review of the data collected has shown that saturation was maintained in the lower, 0.5 m thick compacted layer of the cover, as per the original cover design. The upper cover layer (0.3 m of noncompacted till) was subject to seasonal variations in moisture content, with drying in the summer months and wetting in the fall and spring. Variations in the moisture of the upper layer correlated well with the weather data collected at the site. Spatial variations were noted in the water contents measured over the cover, but a nearly saturated lower layer appears to have been maintained throughout the area monitored.Key words: soil cover, neutron probes, moisture profile, mine waste covers.

Unsaturated sloping layered soil cover system: Field investigation

2011 ◽  
Vol 91 (2) ◽  
pp. 161-168 ◽  
Author(s):  
L. K. Tallon ◽  
M. A. O'Kane ◽  
D. E. Chapman ◽  
M. A. Phillip ◽  
R. E. Shurniak ◽  
...  
Keyword(s):  
Water Content ◽  
Soil Cover ◽  
Mine Waste ◽  
Field Performance ◽  
Field Investigation ◽  
Layered Soil ◽  
Slope Position ◽  
Cover System ◽  
Layering Effect ◽  
And Performance

Tallon, L. K., O'Kane, M. A., Chapman, D. E., Phillip, M. A., Shurniak, R. E. and Strunk, R. L. 2011. Unsaturated sloping layered soil cover system: Field investigation. Can. J. Soil Sci. 91: 161–168. Unsaturated soil cover systems are effective in minimizing the interaction of meteoric water with underlying mine waste. Studies detailing field-monitoring results of layered systems in sloping landscapes are scarce. The objective of this paper was to evaluate the field performance, defined as a reduction in percolation, of a sloping fine-over-coarse-layered cover system at a phosphate mine in the northwestern United States. Cover water content profiles were elevated in the underlying waste material during and after wet periods such as spring snow melt, suggesting that any layering effect of increasing storage capacity was lost. During dry periods, water content profiles suggested a slight benefit due to layering, as water contents were slightly elevated immediately above the cover/waste shale interface. Although there were incidental gains in performance due to layering, the majority of the infiltrating water was stored in the fine-textured layer. This layer was most responsible for limiting percolation into the underlying waste. There was little difference in performance due to slope position. The cover was sufficient in preventing net percolation into the underlying waste shale, and performance was at least partially improved by increased storage at layer interfaces.

scholarly journals Quantification of the inevitable: the influence of soil macrofauna on soil water movement in rehabilitated open-cut mine land

2015 ◽  
Vol 2 (2) ◽  
pp. 853-870 ◽  
Author(s):  
S. Arnold ◽  
E. R. Williams
Keyword(s):  
Soil Water ◽  
Water Movement ◽  
Mine Waste ◽  
Soil Development ◽  
Soil Macrofauna ◽  
Functional Dynamics ◽  
Cover Systems ◽  
Crucial Information ◽  
Mine Sites ◽  
Cover Design

Abstract. Recolonisation of soil by macrofauna (especially ants and termites) in rehabilitated open-cut mine sites is inevitable. In these highly disturbed landscapes, soil invertebrates play a major role in soil development (macropore configuration, nutrient cycling, bioturbation, etc.) and can influence hydrological processes such as infiltration and seepage. Understanding and quantifying these ecosystem processes is important in rehabilitation design, establishment and subsequent management to ensure progress to the desired end-goal, especially in waste cover systems designed to prevent water reaching and transporting underlying hazardous waste materials. However, soil macrofauna are typically overlooked during hydrological modelling, possibly due to uncertainties on the extent of their influence, which can lead to failure of waste cover systems or rehabilitation activities. We propose that scientific experiments under controlled conditions are required to quantify (i) macrofauna – soil structure interactions, (ii) functional dynamics of macrofauna taxa, and (iii) their effects on macrofauna and soil development over time. Such knowledge would provide crucial information for soil water models, which would increase confidence in mine waste cover design recommendations and eventually lead to higher likelihood of rehabilitation success of open-cut mining land.

Cover design for radioactive and AMD-producing mine waste in the Ronneburg area, Eastern Thuringia

2001 ◽  
Vol 21 (2) ◽  
pp. 175-184 ◽  
Author(s):  
Rimbert Gatzweiler ◽  
Silvia Jahn ◽  
Gert Neubert ◽  
Michael Paul
Keyword(s):  
Mine Waste ◽  
Cover Design

Design of a composite soil cover for an experimental waste rock pile near Newcastle, New Brunswick, Canada

1993 ◽  
Vol 30 (4) ◽  
pp. 578-587 ◽  
Author(s):  
Ernest K. Yanful ◽  
Alan V. Bell ◽  
Mark R. Woyshner
Keyword(s):  
New Brunswick ◽  
Soil Cover ◽  
Acid Rock Drainage ◽  
Mine Waste ◽  
Gas Diffusion ◽  
Climatic Conditions ◽  
Waste Rock ◽  
Freezing And Thawing ◽  
Gaseous Oxygen ◽  
Acid Rock

The Heath Steele Waste Rock Project was initiated in 1989 under Canada's Mine Environment Neutral Drainage (MEND) Program to develop and test strategies for managing acid-generating waste rock. The multiphase project involved the identification and selection of a few waste rock piles for field evaluation at the Heath Steele mine site located at about 50 km northeast of Newcastle, New Brunswick. As part of the evaluation, a 0.25-ha acid-generating pile, pile 7/12, was relocated and reconstructed on an impermeable synthetic membrane by end dumping from the perimeter and pushing into the middle section. The pile, which contains about 14 000 t of mine waste rock, has been producing an acidic seepage characterized by high dissolved iron (3.5–13.5 g/L) and sulphate (12.7–43.4 g/L) concentrations. Following the definition of the baseline acid-generating characteristics of the pile and laboratory investigation of potential soil cover materials in the vicinity of the site, a three-layer cover design is proposed. The design calls for a 60 cm thick saturated impermeable cover sandwiched between a 30 cm thick sand base and a 30 cm thick, overlying granular layer. The principal objectives of the design are to obtain a low gas diffusion coefficient to minimize oxygen fluxes and, also, to attain a low hydraulic conductivity to reduce infiltration into the pile. Both objectives can be achieved by compacting the impermeable cover at a density of 95% of Modified Proctor or greater and a water content slightly higher than the optimum value. The design of the cover and the anticipated resulting low gaseous-oxygen fluxes are confirmed by one-dimensional diffusion modelling. The potential for the impermeable layer to remain nearly fully saturated, even under an evaporative flux, is demonstrated by flow modelling. It is noted that the assessment of the durability of the cover with respect to variable climatic conditions (drying, freezing, and thawing) is a critical component of the performance evaluation. Key words : acid rock drainage, soil cover, capillary barrier, oxygen flux, infiltration.

Using Synthetic Climate Datasets for Geotechnical and Geoenvironmental Design Problems

2021 ◽  
Author(s):  
Rashid Bashir ◽  
Muhammad Abid Nawaz Sahi ◽  
Jitendra Sharma
Keyword(s):  
Numerical Simulations ◽  
Soil Cover ◽  
Normal Values ◽  
Expansive Soil ◽  
General Purpose ◽  
Swelling Potential ◽  
Design Problems ◽  
Historical Climate ◽  
Cover Design ◽  
Engineering Projects

Location-specific climate datasets are required for the design and evaluation of a number of civil engineering projects. It requires huge effort to compile a multi-year quality-controlled climate dataset. In this paper, a method of generating simulated daily climate variables of interest from readily-available climate normal using a general purpose weather generator SIMETAW is presented. The accuracy of this method is assessed by comparing the climate datasets generated using SIMETAW with the recorded historical climate datasets for nine different sites across Canada with climates ranging from semi-arid to pre-humid. This comparison was done using visual presentations as well as statistical analyses of the two datasets. It was found that the multi-year daily climate datasets generated by SIMETAW using just 12 monthly climate normal values are fairly similar to the recorded historical climate datasets. The usefulness of SIMETAW-generated climate datasets was demonstrated by using them in numerical simulations of three different design problems, namely, infiltration into soils, swelling potential of an expansive soil, and soil cover design. From the results of these numerical simulations, it is concluded that the SIMETAW-generated multi-year daily climate datasets are satisfactory for use in the geotechnical and geoenvironmental problems of the kind simulated herein.

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