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�i C Reduction Factors: Global factor of safety DESIGN OF GEOCOMPOSITE DRAIN TRANSMISSIVITY MODULES 5 THROUGH 11 NORTH COUNTY RECYCLING CENTER AND SANITARY LANDFILL Transmissivity drain based on infiltration rate (1) The values of RF;,,, RF,, RFu, and RFbc below may be Required: of geocomposite (2) The value of RF., can also be determined using GRI Standard GC8 References: 1. Koerner, R.M., (1998). Designing with Geosynthetics, Fourth Edition. RFI„ =q2.00 2. Geosynthetic Research Institute. (2001). GRI Standard - GC8 3. Giroud, J.P., Zomberg, J.G., and Zhao, A. (2000). "Hydraulic Design of Geosynthetic and RFS, = Granular Liquid Collection Layers", Geosynthetic international, Vol. 7, Nos. 4-5. Design Data: Infiltration rate in to the geocomposite drain q = 4660 gpad RFu = or e = 0.17 inch/day = 5.05E-08 m/sec RFa = Baseliner/geocomposite slope it = 331% P = 0.319 radians Slope length perpendicular to the pipe, measured TSF = FS x RFI" x RF, x RF. x RFw horizontally from crest to toe L = 180 ft 20.8 54.9 m Maximum waste height H = 255 It Waste unit weight Yt = I 90 pct Geocomposite thickness to = 300.00 mil Thickness of the liquid collection layer for geocomposite tcLc = 0.0076 m �i C Reduction Factors: Global factor of safety FS Note: (1) The values of RF;,,, RF,, RFu, and RFbc below may be selected based Koerner (1998) (2) The value of RF., can also be determined using GRI Standard GC8 Reduction factor for intrusion due to elastic deformation RFI„ =q2.00 Reduction factor for creep deformation RFS, = Reduction factor for chemical clogging/precipitation RFu = Reduction factor for biological clogging RFa = Total serviceability factor (TSF) TSF = FS x RFI" x RF, x RF. x RFw TSF = 20.8 Calculations: Total flow at the toe of geocomposite, q= e x L q= 2.77E-06 m2 /sec Required transmissivity, 0 = q/sin B B = 8.84E-06 m2 /sec Required index transmissivity, based on test using 15 -minute seating time using rigid boundary conditions, 81s = 8 x TSF 015= 1.8E-04 m2/sec Conclusions: Check using Giroud et al.(2000) equation: eL _ 0,5 = TSF sin (i + !Aa�L Cos 2/3 1.8E-04 m2isec TSF Required design transmissivity based on test using 100 -hour seating with site-specific boundary conditions, 0100 = 015/RF;,, 0100 = 1.1 E-04 m2/sec The proposed geocomposite should satisfy a index transmissivity (815) of 1.8E-04 m2 /sec when tested under rigid boundary conditions with seating time of 15 minutes The proposed geocomposite should satisfy a design transmissivity (8150) of 1.1 E-04 /sec when when tested under site-specific boundary conditions with seating time of 100 hours Test Conditions: Test normal stress Test hydraulic gradient a = 34425 psf I= 0.33 MIGEOTECHN/CALWCRCSSL-20071Geomt Tranwiss v tylAbdules 5-t M&I t_Geocomp 4660gpad.ads Page 1 of 1