Technology name: Subsurface Barrier Emplacement Development TECHNOLOGY DESCRIPTION: Where: In Situ Media: Arid Soils Targeted Contaminants: Non-Specific, mobile constituents. Contain mobile contaminants by injecting advanced barrier materials from horizontal directionally-drilled boreholes. This technology is commonly employed in civil construction and mining engineering. The use of directionally drilled horizontal boreholes comes from SNLs work in this area. A demonstration of emplacement is planned for FY93. Components- Subsurface, horizontal barriers are needed to provide interim containment of contaminants. The technology uses standard "off-the-shelf" equipment. This will employ some grouts already in use and some that are still under development. Procedures/Reliability- Subsurface barrier emplacement involves putting an impermeable barrier in below a landfill, which is composed of some kind of grouting material. It has to be emplaced without disturbing the landfill. There are two emplacement methods that are being tested. The first is permeation grouting, which uses a slight pressure to inject the grout and takes advantage of the natural porosity of the soil by letting it flow into the soil. The second is jet grouting by mixing, which takes a drill and rotates while injecting the grout. This intentionally fractures the soil and intermixes it with the grout. For both, the boreholes will be drilled approximately two to three meters apart. Input includes pre-barrier emplacement soil conditions especially permeability, soil porosity, grain size distribution, etc. Grout, through various techniques, is injected into the soil. Output includes an evaluation of barrier effectiveness especially, permeability, grout penetration, grout continuity, strength, etc. The main output is an impermeable subsurface barrier that blocks the downward migration of waste. The only limitations related to the emplacement of horizontal subsurface barriers from directionally drilled boreholes lies in the limitations of depth and directional control of the drilling technology. Emplacement techniques are being evaluated to select one that does not create waste. However, given that they entail injecting additional materials into the ground, it is not unreasonable to expect some kind of secondary waste stream. Production of primary wastes is not expected. However, secondary waste will collect in a barrel and be disposed of in drums according to standard procedures. Production of primary wastes is not expected. However, secondary waste will collect in a barrel and be disposed of in drums according to standard procedures. It is expected to be reliable, easily duplicated, and repeatable. This technology, once emplaced, should not require maintenance. General Applications and Limitations- Support/Infrastructure Requirements- Directionally drilled boreholes are necessary. Program Integration Issues and Compatibility with Other Technologies- The overall effectiveness of barriers using this technology has to be evaluated. It should be adaptable to other locations and soil conditions. By design, this technology will be compatible with drilling technology. Operator Staffing/Skill/Training/Physical Requirements- This technology uses standard or slightly modified equipment that is commonly used in civil construction. Standard safety practices as employed in the grouting industry will be employed. ACCEPTABILITY: Failures in the application of this technology will be controlled by secondary emplacement via additional boreholes. This approach is standard practice in ground improvement using grouting and is not considered an unusual occurrence. Emplacement of barrier material will continue until a continuous barrier is completed. Environmental and Aesthetic Impacts- The grouts will be chemically compatible with the local ecology.. Only noise from drilling. Natural Resource Usage- This technology will use chemically compatible grouts that will have minimal effect on natural resources. Energy demands are minimal. Land Use Impacts- Other Socioeconomic Impacts- This field is relatively new to Sandia. This technology is commonly employed in civil construction and mining industries. The subsurface barrier stabilizes and contains the materials within, making them benign and preventing their spread outwards. Therefore, the land outside the landfill is made safe from contamination and is suitable for unrestricted use. Minimal Small work crews are required for use of this technology. STATUS: Maturity- Future Development- Previous Applications (refs.)- Patents- None yet Industrial Partnerships- Denver Grouting; SHB Agra; S & S Harris; Golder Associates, Inc.; Brookhaven National Laboratory; Hanford National Laboratory Denver Grouting- permeation grouting emplacement; SHB Agra- sampling; S & S Harris- directional drilling; Golder Associates, Inc.- grout; Brookhaven National Laboratory- grout formulation an post-grout testing; Hanford National Laboratory- drilling an jet grouting equipment. Contracting and cost sharing. COMPETING TECHNOLOGIES: Vertical Cutoff Walls (Cutoff Walls) EFFECTIVENESS: This will ultimately limit the mobility of contaminants by containing them. COST: Start-up- It is intended that this demonstration will define expected costs for emplacement. Most likely, it would cost around $500K initially (not including drilling equipment). O&M- Operations and maintenance costs will be evaluated during the demonstration of subsurface barrier emplacement technologies. Informal cost sharing involved. Decommissioning- Life-cycle costs will be determined following the demonstration of subsurface barrier emplacement technologies. Regulatory Oversight- This technology aids in the achievement of regulatory cleanup milestones. The person who permits for Sandia has granted this project a permit based upon experimental exclusion. Thus, no real world track record has been established. RATE/SCHEDULE: This will be available following the subsurface barrier emplacement technologies demonstration (2-3 years). This depends on diameter wanted, soil characteristics and the type of grout. However, approximately 20-50 cm with jet grouting for a one and one-half meter diameter. Dependent on location, soil or ground conditions, etc. Approximately four to six months at any real waste site with its inherent problems and delays. SAFETY (worker exposure, safety impacts, etc.): No exposure to hazardous materials/hazards is expected. Standard grouting equipment and techniques are to be employed. No special requirements are envisioned. To be determined. Shouldn't have any accidents because it is underground. However, standard precautions against drilling risks should be taken. REFERENCES: Fiorotto, R.A. Improvement of the Mechanical Characteristics of Soils by Jet Grouting. Italy: Casagrande, Feb. 1992. ---. Diaphragm Walls. Italy, Casagrande, Sept. 1992. Weaver, K.D., E.D. Graf, and Committee 552. "Properties and Proportioning of Cement Base Grouts." 1993 Spring Convention on Geotechnical Grouting. 25 March 1993. Vancouver: ACI, 1993. Allan, M.L., and L.E. Kukacka. "Grout Treated Soil for Low Permeability Barriers Around Waste Landfills." submitted to the American Concrete Institute Materials Journal. Upton, NY: Brookhaven National Laboratory, Yen, Peter T. Recent Developments in Grout Materials. 1993 Spring Convention on Geotechnical Grouting. 25 March 1993. Vancouver, BC: 1993. Ingersoll-Rand Company. Downhole Drills and Bits: The Hole Story. brochure. Roanoke, VA: Ingersoll-Rand, 1990. Allan, M.L. and L.E. Kukacka. "Permeability and Microstructure of Plain an Polypropylene Fibre Reinforced Grouts." Submitted to Cement an Concrete Research. Upton, NY: Brookhaven National Laboratory, June 1993. Bruce, D.A. "Contemporary Practice in Geotechnical Drilling and Grouting. Proceedings for the First Canadian International Grouting Seminar. 18 April 1989. Toronto: FCIGS, 1989. Kosmatka, S.H. Cementious Grouts and Grouting. Portland: Cement Association, 1990. CONTACTS AND ADDRESSES: Department 6121 Developers: Sandia National Laboratories REPORTER: Andrew L. Thomas, Project Geologist Golder Associates Inc. 4104 148th Ave NE Redmond, WA 97552 USA Tel 206-883-0777, Fax 206-882-5498 Processed from ProTech on 8/4/94 at 15:33 VALIDATION: Technology information obtained from: ProTech v3.0, The Prospective Tech- nology Communication System [database on diskette], 1994, U.S. Department of Energy, Office of Environmental Restoration and Waste Management. Publically available from the National Technical Information Service, U.S. Department of Commerce, 5285 Port Royal Rd., Springfield, VA 22161. The ProTech v3.0 manual contains the following disclaimer: This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor Battelle Memorial Institute, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product or process disclosed, or represents that the use would not infringe privately owned rights. Reference herein to any specific commercial product process, or sevice by trade name, trademark, manufacturer or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof, or Battelle Memeorial Institute. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof. No additional validation has been performed on the technology data or description
Last Modified: Tuesday, March 25 1997 12:11