Geonets

Abstract: (NOTE: Each chapter concludes with Problems and References.) 1. Introduction. Need for Landfills. Principal Landfill Requirements. Landfill Components and Configuration. Landfill Envelope. Composite Liners. Benefits of Double Composite Liners. Liner Linkage Mechanisms. Scope and Organization of Book. 2. Landfill Siting and Site Investigation. Siting Considerations. Location Restrictions. Siting Process. Site Investigation. Borrow Source Investigation. Field Hydraulic Conductivity Tests. Material Laboratory Tests. 3. Compacted Clay Liners. Overview Compacted Clay Liners. Compaction and Permeability Considerations. Design of Compacted Clay Liners. Influence of Clods on Hydraulic Conductivity. Effect of Gravel Content on Hydraulic Conductivity. Effect of Freezing and Thawing on Hydraulic Conductivity. Summary Comments Regarding Compacted Clay Liners. 4. Geomembranes. Composition and Thickness of Geomembranes. Current Uses of Geomembranes in Landfills. Tensile Behavior of Geomembranes. Friction Behavior of Geomembranes. Tension Stresses Due to Unbalanced Friction Forces. Tension Stresses Due to Localized Subsidence. Runout and Anchor Trenches. Assessment of Leakage through Liners. Concluding Comments Regarding Geomembranes. 5. Geosynthetic Clay Liners. Types and Current Uses of Geosynthetic Clay Liners. Hydraulic Conductivity. Ability to Withstand Differential Settlement. Shear Strength. Differences between Geosynthetic Clay Liners and Compacted Clay Liners. Contaminant Transport through Geosynthetic Clay Liner and Compacted Clay Liner. Comparison of Mass Transport through a GCL and CCL. Recommendations for Use of Geosynthetic Clay Liners. Summarizing Comments Regarding Geosynthetic Clay Liners. 6. Engineering Properties of Municipal Solid Waste. Constituents of Municipal Solid Waste. Unit Weight of Municipal Solid Waste. Moisture Content of Municipal Solid Waste. Porosity of Municipal Solid Waste. Hydraulic Conductivity of Municipal Solid Waste. Field Capacity and Wilting Point of Municipal Solid Waste. Shear Strength of Municipal Solid Waste. Compressibility of Municipal Solid Waste. 7. Leachate Generation and Evaluation in MSW Landfills. MSW Leachate Characterization. Factors Affecting Leachate Quantity. Estimation of Leachate Production Rate in an Active Condition. Estimation of Leachate Production Rate in a Postclosure Condition. Hydrologic Evaluation of Landfill Performance (HELP) Model. 8. Liquid Drainage Layer. Profile of Leachate Drainage Layer. Soil Drainage and Filtration Layer. Geotextile Design for Filtration. Geonet Design for Leachate Drainage. Estimate of Maximum Liquid Head in a Drainage Layer. 9. Leachate Collection and Removal Systems. Subbase Grading. Leachate Collection Trenches. Selection of Leachate Collection Pipe. Deformation and Stability of Leachate Collection Pipe. Sump and Riser Pipes. Leachate Removal Pumps. 10. Gas Collection and Control Systems. Gas Generation. Gas Composition. Factors Affecting Gas Generation. Gas Generation Rate. Gas Migration. Types and Components of Gas Collection Systems. Gas Control and Treatment. Design of Gas Collection System. 11. Final Cover System. Components of Final Cover System. Alternative Landfill Cover. Field Study of Landfill Covers. Soil Erosion Control. Effects of Settlement and Subsidence. Differential Subsidence Case History. 12. Landfill Settlement. Mechanism of Solid Waste Settlement. Effect of Daily Cover. Landfill Settlement Rate. Estimation of Landfill Settlement. Effect of Waste Settlement on Landfill Capacity. Other Methods for Estimating Landfill Settlement. Estimation of Landfill Foundation Settlement. 13. Landfill Stability Analysis. Types of Landfill Failures. Factors Influencing Landfill Stability. Selection of Appropriate Properties. Veneer Slope Stability Analysis. Subsoil Foundation Failures. Waste Mass Failures. Concluding Remarks. 14. Vertical Landfill Expansions. Considerations Involved in Vertical Expansions. Liner Systems for Vertical Expansion. Settlement of Existing Landfill. Estimation of Differential Settlement Due to Waste Heterogeneity. Vertical Expansion over Unlined Landfills. Design Considerations for Landfill Structures. Geosynthetic Reinforcement Design for Vertical Expansions. Stability Analysis for Vertical Expansion. 15. Bioreactor Landfills. Introduction. Liquids Managements Strategies. Concepts of Waste Degradation. Leachate Recycling Methods. Bioreactor Landfill Issues and Concerns. Performance-to-Date. Summary Comments. 16. Construction of Compacted Clay Liners. Subgrade Preparation. Soil Materials for Compacted Soil Lines. Compaction Objectives and Choices. Initial Saturation Specifications. Clay Liner Compaction Considerations. Compaction Specifications. Leachate Collection Trench Construction. Protection of Compacted Soil. Field Measurement of Water Content and Dry Unit Weight. Construction Quality Assurance and Quality Control Issues. 17. Installation of Geosynthetic Materials. Material Delivery and Conformance Tests. Installation of Geomembranes. Installation of Geonets. Installation of Geotextiles. Installation of Geocompostes. Installation of Geosynthetic Clay Liners. 18. Postclosure Uses of MSW Landfills. Athletic and Recreational Facilities. Industrial Development. Aesthetics. Concluding Remarks. Appendix I. Help Model Input and Output-Active Condition. Appendix II. Help Model Input and Output-Postclosure Condition. Index.

Abstract: A low friction slip-sleeve wrap for buried structures such as pipelines, pilings or the like The pipe is coated in a polymer coating such as HDPE or FBE, then wrapped in a polymer mesh such as geonet or geogrid without any friction-increasing means such as friction coatings or fillings or bonding of layers Finally, a layer of geotextile is wrapped over the polymer mesh layer In addition to the reduction of friction and shear transfer from the ground to the pipe or foundation element, which acts to protect the structure from damage due to earthquakes or land slippage, the low friction slip-sleeve wrap of the invention has several other advantages The porosity of the geotextile allows for cathodic protection The geogrids, geonets, and geotextiles used in the wrap are relatively inexpensive and readily available Moreover, the wrap can be applied in the field easily, with minimal time delay, and located as required along all or selected lengths of the pipeline or foundation element Because the wrapping can be applied easily in sections, it also can be used on large conduits, including large diameter water pipelines (greater than 4 ft) and tunnels

Abstract: In order to increase coefficients of friction and thereby enable steeper slopes and increased capacity to be provided in a waste containment landfill enclosure 1 with a side wall and base lining system 2 and a cover lining system 3, the lining systems have a geomembrane 4, 6, 16 in contact with a geonet 5, 7, 17 and a geonet 7, 17 in contact with a geotextile 8, 18. The geomembranes 4, 6, 16 and the geonets 5, 7, 17 have some of their contacting surfaces firmly retaining projecting particles of grit which have been engaged in the plastics material when the respective surface of the plastics material has been softened or melted. In order to further increase the steepness of the slopes, gritted geogrids 9, 19 are laid over the lining systems 2, 3 and secured in position.