Evolution of landform design concepts

Howard, Evan; Loch, R. J.; Vacher, C. A.

doi:10.36487/acg_rep/1008_08_howard

Cited by 4 publications

(4 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Nevertheless, not all concave shapes are mechanically stable, requiring a rational definition of those concave slopes that provide the desired degree of stability expressed in terms of a desired factor of safety (FS). For example, Howard et al (2011) point out the risk associated with the growing practice of shaping slopes to reflect natural regional landforms without appropriate stability and erosion analyses and without accounting for the limited precision of the construction equipment employed to build concave profiles. Hence, the objectives of this work are to (1) describe concave shapes that provide a desired degree of stability (a desired FS) for given soil properties, (2) provide a quantitative measure of the difference in soil loss (erosion) between concave and planar slopes that satisfy the same degree of mechanical stability, and (3) investigate the precision to which concave forms can be constructed and how this affects the desired slope stability.…”

Section: Introductionmentioning

confidence: 99%

Design of Stable Concave Slopes for Reduced Sediment Delivery

Jeldes

Drumm

Yoder

2015

J. Geotech. Geoenviron. Eng.

View full text Add to dashboard Cite

Constructed slopes are traditionally given a planar form. However, natural slopes are more likely to be concave in cross section. In addition, laboratory and computational studies have demonstrated that concave slopes yield less sediment than planar slopes. With current autoguided construction equipment, it is now possible to construct slopes with concave profiles and a more natural appearance, yet a simple method to describe such concave slopes for a given level of mechanical stability does not exist. This article begins with an examination of concave shapes satisfying a desired degree of stability and compares results with those from the FEM and limit-equilibrium method of analysis. An erosion model is used to demonstrate that the concave slopes proposed here yield 15-40% less sediment than planar slopes with the same factor of safety. Finally, a sensitivity analysis suggests that reasonable construction deviations do not compromise the stability of typical concave slopes.

show abstract

Section: Introductionmentioning

confidence: 99%

Design of Stable Concave Slopes for Reduced Sediment Delivery

Jeldes

Drumm

Yoder

2015

J. Geotech. Geoenviron. Eng.

View full text Add to dashboard Cite

show abstract

“…In Australia, there are clear requirements and guidelines to construct post-mining landforms that are safe, stable and non-polluting for humans, flora and fauna, and capable of sustaining land use after mining finishes. Howard et al (2011) make a synthesis for different Australian states, referring to laws for Western Australia and Queensland and guidelines in such a direction in New South Wales. In Canada, mining legislation requests the reconstruction of 'self-sustained' landforms and ecosystems that are compatible with a healthy environment and the maintenance of other human activities.…”

Section: Physical and Chemical Stabilisation In Mine Rehabilitationmentioning

confidence: 99%

Geomorphic landform design, landscape evolution modelling and geochemical stabilisation for mine closure at the LIFE RIBERMINE project, Spain and Portugal

Duque¹,

Palomino²,

Hancock³

et al. 2022

Mine Closure 2022: 15th Conference on Mine Closure

View full text Add to dashboard Cite

The environmental impact of mining on landscape systems is well recognised. New technologies for landscape reconstruction have been developed and advanced in recent decades alongside the recognition of the environmental impact and resultant societal expectation of a restored and integrated post-mining system. A post-mining landscape requires physical stability (and, if present, chemical stability). Australia, the United States, Canada, Chile and the European Union, among others, have mine regulations requiring non-polluting post-mining landforms. We describe mine closure actions in Spain and Portugal (LIFE RIBERMINE project) that integrate two geomorphic landform design techniques: (a) GeoFluv-Natural Regrade, for unconsolidated sandy waste dumps in Spain and pyrite waste deposits in Portugal, and (b) Talus Royal, for hard-rock residual highwalls in Spain. SIBERIA landscape evolution modelling has been used to evaluate the erosional stability of post-mining geomorphic landform designs in Spain. Acid mine drainage (AMD) chemical stabilisation and remediation measures were combined with geomorphic landform designs in Portugal. Design procedures of LIFE RIBERMINE took place in the years 2019 and 2020, being constructed in 2020, 2021 and 2022. Design and construction phases were executed as planned, with minor deviations. The monitoring procedures (lasting until 2029) are intended to verify the real effectiveness of such solutions. The improvement of the water quality downstream in the demonstration site of Spain (Santa Engracia mine, Peñalén) will be quantified by measuring the sediment emission-immission to water bodies. Erosion rate (sediment yield) at the Santa Engracia mine previous to LIFE RIBERMINE was 353 t ha -1 yr -1 . The target values after restoration should range between 4 and 15 t ha -1 yr -1 , forecasted by the SIBERIA modelling and measured by monitoring similar geomorphic-based solutions at nearby mines. Regarding turbidity, suspended sediment concentrations (SSC) at a pre-rehabilitation phase were 391 g l -1 and target values (baseline) are 24 g l -1 . In Portugal (Lousal, Grândola), where AMD is the main problem, it is expected that the dissolved potentially toxic elements' maximum concentration values of Pb (0.9 mg/L), Cd (0.5 mg/L), Zn (80 mg/L) and Cu (20 mg/L) are reduced to values at least closer to the values established by the Portuguese legislation for minimum water quality in surface waters (Pb -0.05 mg/L, Cd -0.01 mg/L, Zn -0.5 mg/L, Cu -0.1 mg/L). If the AMD treatment measures are effective, initial physicochemical values of pH (between 1.8 and 3.1) and conductivity (2.71-3.9 mS/cm) should also change to near common non-polluted water values (around pH -7, conductivity -0.75 mS/cm). LIFE RIBERMINE aims to significantly reduce mined land environmental contamination and to demonstrate the efficiency of a combination of some best available techniques for mine closure. The performance results can be used to consider applying the innovative rehabilitation and remediation designs to other min...

show abstract

“…In comparison, a process-based model such as WEPP operates on a daily time step, provides erosion predictions on an event basis (rather than annual rates only), predicts erosion changes along a slope length, and can account for erosion in rills. Howard et al (2013) provides a comparison of the RUSLE and WEPP models and how they can be used in mine site closure designs. The WEPP model was used to predict runoff and erosion based on the calibrated erodibility parameters derived from the field tests.…”

Section: Initial Erosion Modelling and Calibrationmentioning

confidence: 99%

Integration of field erosion measurements with erosion models and 3D civil design tools for development of erosion resistant cover systems

Peroor¹,

Howard²,

Braun³

et al. 2019

Proceedings of the International Conference on Mine Closure

Self Cite

View full text Add to dashboard Cite

Post-closure maintenance activities for various inactive copper tailings impoundments owned by BHP in Arizona (USA) require frequent erosion-related inspections and repairs. BHP assessed these recurring costs and post-closure hazards and commissioned a study of alternative methods to design a more robust, erosionresistant solution. The study combined field erosion testing, 2D and 3D erosion models, and landform design tools in an innovative way that allowed BHP to make an informed decision regarding improvements to the erosional stability of the tailings impoundments. The study started with field-based material testing. Simulated rainfall and overland flows were applied to 13 test surfaces representing different cover systems, and measurements of infiltration capacity, interrill and rill erodibility, flow shear stress, and sediment size and density distributions were made. The field measurements allowed calibration of parameters for the Water Erosion Prediction Project (WEPP) erosion model and SIBERIA landform evolution model for the different cover systems. The study team used the calibrated WEPP model to evaluate the erosion performance of linear and curvilinear embankment profiles and retained cover systems that met minimum erosion performance standards. The performance standards were established using data on the erosion of surrounding undisturbed vegetated hillslopes and a review of the published literature detailing erosion benchmarks for rangelands in southwestern USA. The design team developed 3D surfaces of the linear and curvilinear slope profiles developed from WEPP modelling, and more complex 3D surfaces developed from the GeoFluv TM software. These surfaces were subjected to 3D landform evolution modelling using SIBERIA. Inputs to the SIBERIA model and GeoFluv TM software were informed using data collected during the field studies. Each SIBERIA model iteration provided insight regarding short-term and long-term erosion performance for each 3D surface and cover system. The design team produced initial and sustaining capital cost estimates for the final engineering designs based on this output. This paper details the innovative approach taken to integrate field measures of erodibility, 2D and 3D models, and civil 3D design software to produce defensible long-term closure designs that are material and site specific, and cost-effective.

show abstract

Evolution of landform design concepts

Cited by 4 publications

References 0 publications

Design of Stable Concave Slopes for Reduced Sediment Delivery

Design of Stable Concave Slopes for Reduced Sediment Delivery

Geomorphic landform design, landscape evolution modelling and geochemical stabilisation for mine closure at the LIFE RIBERMINE project, Spain and Portugal

Integration of field erosion measurements with erosion models and 3D civil design tools for development of erosion resistant cover systems

Contact Info

Product

Resources

About