2018-12-26_REVISION - M2008078 (31)

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1.3 ABBREVIATIONS AND DEFINITIONS A. API -American Petroleum Institute B. ASTM- American Society for Testing and Materials C. Slurry Trench-A narrow,vertical-walled trench of specified width excavated by the slurry trench method and backfilled with specified materials to form a cutoff wall of low permeability. The terms "Slurry Trench"and"Slurry Wall"are used interchangeably in these specifications. D. Slurry Trench Method-A method of excavating a narrow,vertical trench using a slurry mixture to support the trench walls and prevent movement of groundwater into or through the excavated trench. E. Water-Bentonite Slurry- A stable colloidal suspension of powdered bentonite in water. The terms "slurry"and "water-bentonite slurry"are used interchangeably in these specifications. F. Soil-Bentonite(SB)Backfill-A homogeneous mixture of specified soil material, bentonite and water. The terms"soil-bentonite backfill" and"backfill"are used interchangeably in these specifications. G. Slurry Trench Specialist- An individual who has had proven and successful experience in slurry trench construction and is knowledgeable of: (1)the proper methods employed to mix slurry and backfill, (2) the use,testing and control of bentonite as a slurry, (3)construction equipment, (4)excavation and backfill operations, and(5)testing for slurry trench quality control. H. Working Platform- The working platform is the surface of compacted fill and/or excavated surface from which the slurry wall is constructed. The work platform is to be relatively level, stable. 1. Supplemental Fines—The soil that contains a significant percentage of fines content(passing the-#200 sieve or .075 min in the largest dimension)that is added to the excavated soil for the purpose of increasing the overall fines content of the soil-bentonite backfill. J. Key Depth- The depth to which the slurry trench is excavated into less weathered suitable bedrock providing the connection between the slurry wall and the less weathered bedrock. 1.4 SUBMITTALS A. The following information shall be submitted at least 4 weeks prior to construction. 1. Qualifications of Contractor a. The Contractor, shall submit evidence including resumes and references that he or his subcontractor is experienced and competent to construct a soil-bentonite slurry trench. The slurry trench company shall have at least five years of prior experience in constructing slurry walls,with at least five 'SB slurry walls of similar scope and magnitude. The Contractor shall have sufficient competent experienced personnel to carry out the operations specified. i. In particular, a slurry trench specialist hired by the Contractor shall supervise the construction, slurry preparation, and Contractor's quality control. The slurry trench specialist shall have at least three years of experience and/or three projects in successful construction of slurry walls,with at least two SB slurry walls of similar scope and magnitude. b. The company name, key contact, and qualifications of the Contractor's off-site laboratory shall be submitted. The laboratory will have previous experience with slurry wall backfill materials, experienced laboratory technicians,and flexible wall permeability testing equipment. 2. Work Plan- The Contractor shall submit a detailed operating plan describing his proposed construction equipment, procedures, and schedules. This shall include, but not be limited to,the Contractor's plan for: a. Coordinating the construction, maintenance and removal of working platforms, mixing pads, and haul roads with the Owner, general contractor or other contractors on site. b. Equipment set-up and site use layout including storage areas, haul roads and work platform dimensions. 31 66 17-2 Prowers Aggregate Operators, LLC West Farm Pit Phase 2 Slurry Wall Soil-Bentonite Slurry Walls