CE 5327 - GEOTECHNICAL PRACTICE FOR WASTE DISPOSAL Homework Assignment # 5 (Due 5:00pm Monday, February 21, 2005) 1. A contractor needs to purchase suitable clayey soil for a landfill soil liner construction project. The landfill liner covers 24 acres and the liner has a thickness of 2 ft. The specifications call for a compaction water content of 18% and a compacted dry density of 110 lb/ft 3 . At the borrow source the soil is sold by the ton, not by cubic yard. The water content of the stockpiled soil at the borrow source is 7.0% (a) How many tons of soil should the contractor purchase to have exactly the correct volume of compacted material? Calculate quantities for 1 sq yd of liner. (b) How much water should be added for each square yard of completed liner to bring the water content up to the specified value? [1 US ton = 2000 lbs. 1 acre = 43,560 sq ft] 2. TAC Chapter 335, Subchapter G: Locations Standards stipulate that “a landfill may not be located in areas where soil unit(s) within five feet of the containment structure have a unified soil classification of GW, GP, GM, GC, SW, SP, or SM.” The following results were obtained on two types of soils found within 5ft of a proposed hazardous waste landfill base. Classify the two soils according to USCS procedure and hence determine whether there should be a concern with respect to the suitability of the selected site. Percent Passing Sieve Size Soil A Soil B 1in. 100 ¾ in. 85 ½ in. 70 3/8 in. 100 60 No.4 76.5 48 No.10 60.0 30 No.40 39.7 16 No.100 10 No.200 15.2 2 Liquid Limit 30 Non- Plastic Plastic Limit 12 Non- Plastic 3. The following data is available for soils from 4 different sources. In each case determine whether the soil is suitable for clay liner construction. Use criteria specified by TCEQ. If they do meet the requirements, indicate your reasons for disqualifying the material. Also, mention what problems we may anticipate if we use the material for clay liner construction purposes. (a) 85.6% passing No. 10 sieve; 72.3% passing No.40 sieve. 58.8% passing No. 200 sieve; Liquid Limit is 42.5%, and Plasticity Index is 24.3%. (b) Grain-Size Analysis Results: US Std. Sieve Percent Passing 1 in. 100 3/4 in. 90 3/8 in. 82 No. 4 70 No.10 65 No. 40 54 No. 200 25 Liquid Limit = 29% Plastic Limit = 19% (c) and (d) Particle Size Analysis Data: Particle Size Percent Finer Soil C Soil D 63 mm 100 - 20 mm 76 - 6.3 mm 65 - 2 mm 59 - 600 μm 54 - 212 μm 47 100 63 μm 34 95 20 μm 23 69 6 μm 14 46 2 μm 7 31 Liquid Limit 26 42 Plastic Index 9 18 . CE 53 27 - GEOTECHNICAL PRACTICE FOR WASTE DISPOSAL Homework Assignment # 5 (Due 5: 00pm Monday, February 21, 20 05) 1. A contractor needs to purchase. 65 No. 40 54 No. 200 25 Liquid Limit = 29% Plastic Limit = 19% (c) and (d) Particle Size Analysis Data: Particle Size Percent Finer Soil C Soil D 63 mm 100 - 20 mm 76 - 6.3 mm 65. for clay liner construction purposes. (a) 85. 6% passing No. 10 sieve; 72.3% passing No.40 sieve. 58 .8% passing No. 200 sieve; Liquid Limit is 42 .5% , and Plasticity Index is 24.3%. (b) Grain-Size