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Shaw Environmental, Inc. Check using Giroud et al.(2000) equation: 8 =TRF e ,S / 1.8E-05 m2/sec sin ,Q + t TSL COS 2Q Global factor of safety = FS = 4.0 Factor of Safety Is > 2, therefore, Acceptable N:IGEOTECHNICAL\NCRCBSL-2007\Geonet Transmissivit)AModule INCRCSSL Modules 1-2 8 3 Geonet_100-gpad.xfs Page 1 of 1 NORTH COUNTY RECYCLING CENTER AND SANITARY LANDFILL FLOW CAPACITY OF THE EXISTING GEONET ON MODULES 1 AND 3 Required: Verify if the existing geonet is adequate to convey the anticipated peak leachate flow References: 1. Koerner, R.M., (1998). Designing with Geosynthetics, Fourth Edition. 2. Geosynthetic Research Institute. (2001). GRI Standard - GC8 3. Giroud, J.P., Zomberg, J.G., and Zhao, A. (2000). "Hydraulic Design of Geosynthetic and Granular Liquid Collection Layers", Geosynthetic International, Vol. 7, Nos. 4-5. Design Data: Infiltration rate in to the geonet based on Module 3 peak pumping rate q = 100 gpad or e = 0.0037 inch/day = 1.08E-09 m/sec Baseliner/geocomposite slope, perpendicular to the pipe: i1 = 2 % Pipe slope i2 = 1 % Effective slope in the direction of flow i = 2.236 % P = 0.022 radians Slope length perpendicular to the pipe, measured horizontally from pipe to the crest of slope L1 = 180 ft Effective slope length in the direction of flow, measured horizontally L = 201 it = 61.4 m Maximum waste height H = 165 it Waste unit weight y, = 901 pcf Maximum normal stress a = 14850 psi Geonet-geotextile thickness 240.00 mil Thickness of the liquid collection layer for geocomposite tcLc = 0.0061 m Measured index transmissivity at 16,000 psf normal stress and hydraulic gradient of 0.02 015 = 7.13E-05 m`/sec Reduction Factors: Note: (1) The values of RF;,,, RF, RFa, and RFa below may be selected based Koerner (1998) (2) The value of RFQ can also be determined using GRI Standard GC8 Reduction factor for intrusion due to elastic deformation RF;,, = 1.00 [A value of 1.0 is used for RFI„ because the test configuration is the same as in the field] Reduction factor for creep deformation RF, = 1.70 Reduction factor for chemical clogging/precipitation RF, = 1.75 Reduction factor for biological clogging RFb, = 2.00 Total reduction factor (TRF) TRF = RFI„ x RF, x RFa x RFa TSF = 6.0 Calculations: Total flow at the toe of geocomposite, q= e x L q= 6.64E-08 m2/sec Required transmissivity (without. TRF and a global factor of safety), 0 = q/sin p e = 2.97E-06 m2/sec Required transmissivity (without a global factor of safety) 015 = 8 x TRF 815 = 1.8E-05 m2 /sec Check using Giroud et al.(2000) equation: 8 =TRF e ,S / 1.8E-05 m2/sec sin ,Q + t TSL COS 2Q Global factor of safety = FS = 4.0 Factor of Safety Is > 2, therefore, Acceptable N:IGEOTECHNICAL\NCRCBSL-2007\Geonet Transmissivit)AModule INCRCSSL Modules 1-2 8 3 Geonet_100-gpad.xfs Page 1 of 1