- Email: [email protected]
Gully erosion minimization on reclaimed surface mines using SSAST computer model
182A
SURFACE STRUCTURES:GROUNDWATER
954254 Application of the observational method to a deep basement excavated using the top-down method Y. Ikuta, M. Maruoka, M. Aoki & E. Sato, Geotechnique, 44(4), 1994, pp 655-664. In this paper, the observational construction method is proposed whereby the excavation sequence is modified and optimized during construction. An example of its application is given. The method can be used to revise and confirm the design assumptions, for example by back-analysing the initial excavation stages. The new design assumptions can then be used to predict the precise behaviour of the subsequent stages. The measured data are also used to rationalize the excavation work during the subsequent stages. (Authors)
954255 The observational approach to design of a sheet-piled retaining wall D. K. Young & E. W. L. Ho, Geotechnique, 44(4), 1994, pp 637-654. The Brickpit structure at the Channel Tunnel terminal at Folkestone comprises a reinforced earth embankment supporting the railway line close to the tunnel portal. A principal constraint on the design was the need to found the structure close to and substantially below the power cables which link the British and French national grids. Although other structural forms of retaining wall would have been stiffer, there were major attractions in the use of an anchored sheetpiled retaining wall. The paper describes the gound conditions and site investigations. The effects of the wall on the adjacent power cables are considered and an observational approach to construction is developed which incorporates finite element modelling, a field trial and construction monitoring. (from Authors)
Construction methods 954256 The planning, design and construction parameters of Hong Kong's new airport D. E. Oakervee, Proceedings - ICE." Transport, 105(4), 1994, pp 235-247. This paper outlines the forecast air traffic to Hong Kong in the 21st century and the decision to build a new international airport at Chek Lap Kok. It gives details of the planning, design and construction of this immense project. (Author)
954257 Strategic cover up ANON, Ground Engineering, 27(9), 1994, pp 14-15. Describes clean-up operations at an 80ha contaminated redevelopment site in Derby, UK. A slurry cut-off wall is being built to isolate the worst contaminated areas. Construction is being complicated by live services through the site. A granular blanket capillary break will cap the site and prevent upward migration of contaminants. (J.M.MeLaughlin)
Groundwater problems 954258 Gully erosion minimization on reclaimed surface mines using SSAST computer model R. A. McKenney & T. W. Gardner, Journal oflrrigation & Drainage Engineering - ASCE, 120(5), 1994, pp 910-924. The Stable Slope and Sediment Transport (SSAST) model, an event-based computer model, uses postmine hydrology and
median overburden grain size of a reclaimed-surface mine to calculate a stable slope for the longitudinal channel profile. Analyses indicate that SSAST can predict stable longitudinal channel profiles for reclamation of surface mines in the humid, temperate Northeastern US. Disequilibrium among slope form, surface hydrology, and erosional process on reclaimed surface coal mines can cause gully erosion and sediment loads that are significantly elevated above natural values. (Authors)
954259 Close-out - the risk of too much water C. V. McQuade, in: Managing risk. Proc. 4th open pit conference, Perth, 1994, (AIMM), 1994, pp 35-38. At many locations in Australia the decommissioning of mining operations will require the disposal of excess water. If the water is contaminated its disposal may be restricted by government guidelines. The timing of water disposal may be critical to the schedule of close-out. The uncertainty of the annual rainfall input to the water storage and disposal system may determine the success or failure of close-out. The uncertainty associated with any outcome can be used to determine the reliability of the system, or inversely its risk. The technique of Monte Carlo simulation, using the uncertainty in annual rainfall, is applied to quantify the risks associated with water disposal as part of the requirements for close-out in two case studies. Simulation modelling is able to provide information on the likely response of mine water management systems and the level of risk. This information is required to efficiently plan and manage the disposal of water for close-out. (from Author)
954260 Treatment of metal industrial wastewater by fly ash and cement fixation C. H. Weng & C. P. Huang, Journal of Environmental Engineering - ASCE, 120(6), 1994, pp 1470-1487. A process for the treatment of industrial wastewater containing heavy metals, using fly ash adsorption and cement fixation of the metal-laden adsorbent, was investigated. Results show that the fly ash can be an effective metal adsorbent, at least for Zn(II) and Cd(II) in dilute industrial wastewaters. Compressive strength and leaching tests results suggest that metal-laden fly ash can be considered for use in secondary construction materials. (Authors) 954261 Statistical analyses of compacted clay landfill finers. Part 1: model development S. 13. Donald & E. A. McBean, Canadian Journal of Civil Engineering, 21(5), 1994, pp 872-882. By examining the flux of leachate through a compacted clay liner of a typical engineered landfill, an acceptance protocol suitable for compacted clay landfill liners is derived. Determination of the equivalent hydraulic conductivity of the clay liner is accomplished by comparing the flux of lcachate through a homogeneous representation of the clay with the flux obtained by Monte Carlo analyses. Acceptance criteria are subsequently developed based on a statistical technique which calculates the confidence limits about a percentile of a probability distribution as well as about the mean of the distribution. The results indicate that the hydraulic conductivity of a compacted clay landfill liner follows a loguormai distribution and exhibits virtually no spatial correlation structure. In addition, for liners exhibiting a geometric mean conductivity of 10.7 cm/s and a standard deviation of 0.3, the geometric mean value is a conservative estimate of the hydraulic conductivity of the clay, provided the liner is constructed in a seriees of four 150 mm lifts. (Authors)
SURFACE STRUCTURES:GROUNDWATER
954254 Application of the observational method to a deep basement excavated using the top-down method Y. Ikuta, M. Maruoka, M. Aoki & E. Sato, Geotechnique, 44(4), 1994, pp 655-664. In this paper, the observational construction method is proposed whereby the excavation sequence is modified and optimized during construction. An example of its application is given. The method can be used to revise and confirm the design assumptions, for example by back-analysing the initial excavation stages. The new design assumptions can then be used to predict the precise behaviour of the subsequent stages. The measured data are also used to rationalize the excavation work during the subsequent stages. (Authors)
954255 The observational approach to design of a sheet-piled retaining wall D. K. Young & E. W. L. Ho, Geotechnique, 44(4), 1994, pp 637-654. The Brickpit structure at the Channel Tunnel terminal at Folkestone comprises a reinforced earth embankment supporting the railway line close to the tunnel portal. A principal constraint on the design was the need to found the structure close to and substantially below the power cables which link the British and French national grids. Although other structural forms of retaining wall would have been stiffer, there were major attractions in the use of an anchored sheetpiled retaining wall. The paper describes the gound conditions and site investigations. The effects of the wall on the adjacent power cables are considered and an observational approach to construction is developed which incorporates finite element modelling, a field trial and construction monitoring. (from Authors)
Construction methods 954256 The planning, design and construction parameters of Hong Kong's new airport D. E. Oakervee, Proceedings - ICE." Transport, 105(4), 1994, pp 235-247. This paper outlines the forecast air traffic to Hong Kong in the 21st century and the decision to build a new international airport at Chek Lap Kok. It gives details of the planning, design and construction of this immense project. (Author)
954257 Strategic cover up ANON, Ground Engineering, 27(9), 1994, pp 14-15. Describes clean-up operations at an 80ha contaminated redevelopment site in Derby, UK. A slurry cut-off wall is being built to isolate the worst contaminated areas. Construction is being complicated by live services through the site. A granular blanket capillary break will cap the site and prevent upward migration of contaminants. (J.M.MeLaughlin)
Groundwater problems 954258 Gully erosion minimization on reclaimed surface mines using SSAST computer model R. A. McKenney & T. W. Gardner, Journal oflrrigation & Drainage Engineering - ASCE, 120(5), 1994, pp 910-924. The Stable Slope and Sediment Transport (SSAST) model, an event-based computer model, uses postmine hydrology and
median overburden grain size of a reclaimed-surface mine to calculate a stable slope for the longitudinal channel profile. Analyses indicate that SSAST can predict stable longitudinal channel profiles for reclamation of surface mines in the humid, temperate Northeastern US. Disequilibrium among slope form, surface hydrology, and erosional process on reclaimed surface coal mines can cause gully erosion and sediment loads that are significantly elevated above natural values. (Authors)
954259 Close-out - the risk of too much water C. V. McQuade, in: Managing risk. Proc. 4th open pit conference, Perth, 1994, (AIMM), 1994, pp 35-38. At many locations in Australia the decommissioning of mining operations will require the disposal of excess water. If the water is contaminated its disposal may be restricted by government guidelines. The timing of water disposal may be critical to the schedule of close-out. The uncertainty of the annual rainfall input to the water storage and disposal system may determine the success or failure of close-out. The uncertainty associated with any outcome can be used to determine the reliability of the system, or inversely its risk. The technique of Monte Carlo simulation, using the uncertainty in annual rainfall, is applied to quantify the risks associated with water disposal as part of the requirements for close-out in two case studies. Simulation modelling is able to provide information on the likely response of mine water management systems and the level of risk. This information is required to efficiently plan and manage the disposal of water for close-out. (from Author)
954260 Treatment of metal industrial wastewater by fly ash and cement fixation C. H. Weng & C. P. Huang, Journal of Environmental Engineering - ASCE, 120(6), 1994, pp 1470-1487. A process for the treatment of industrial wastewater containing heavy metals, using fly ash adsorption and cement fixation of the metal-laden adsorbent, was investigated. Results show that the fly ash can be an effective metal adsorbent, at least for Zn(II) and Cd(II) in dilute industrial wastewaters. Compressive strength and leaching tests results suggest that metal-laden fly ash can be considered for use in secondary construction materials. (Authors) 954261 Statistical analyses of compacted clay landfill finers. Part 1: model development S. 13. Donald & E. A. McBean, Canadian Journal of Civil Engineering, 21(5), 1994, pp 872-882. By examining the flux of leachate through a compacted clay liner of a typical engineered landfill, an acceptance protocol suitable for compacted clay landfill liners is derived. Determination of the equivalent hydraulic conductivity of the clay liner is accomplished by comparing the flux of lcachate through a homogeneous representation of the clay with the flux obtained by Monte Carlo analyses. Acceptance criteria are subsequently developed based on a statistical technique which calculates the confidence limits about a percentile of a probability distribution as well as about the mean of the distribution. The results indicate that the hydraulic conductivity of a compacted clay landfill liner follows a loguormai distribution and exhibits virtually no spatial correlation structure. In addition, for liners exhibiting a geometric mean conductivity of 10.7 cm/s and a standard deviation of 0.3, the geometric mean value is a conservative estimate of the hydraulic conductivity of the clay, provided the liner is constructed in a seriees of four 150 mm lifts. (Authors)