Laserfiche WebLink
' <br />verified through construction observation and tasting. The original levee <br />was judged to be well compacted based on the field exploration program. <br />Both fill materials were assumed to have a moist density Of 135 p f. A <br />density of 1 p f was assumed for the foundation soils based on density <br />tests on samples Obtained from test holes. Due to the high percentage of <br />coarse grained particles, gravels, and cobbles, all three materials were <br />judged to have low compressibility. Results from direct shear tests <br />performed on samples of the levee fill and foundation soils are shown in <br />Figs. 13 and 14. An angle of internal friction o 33 degrees and a cohesion <br />of 47 psf were measured for the levee fill, and an angle of internal friction of <br />degrees and a cohesion of 1 psf were measured for the foundation <br />soils. Due to the limited size of laboratory equipment, test procedures <br />require gravel and cobble be scalped from the samples tested. The strength <br />of the materials is likely higher than that reflected by the laboratory <br />measurements due to the interlocking effect of gravels and cobbles. For <br />slope stability analysis, a friction angle of 45 degrees and a cohesion of 200 <br />psf were assumed for both the levee and the foundation soils. <br />Permabulit For seepage analysis, the permeability of saturated levee and <br />foundation soils was assumed to be on the order of 100 ftlyr based on field <br />and Iarboratory testing. The flog of grater through saturated soils is only one <br />part of the overall seepage analysis. Most of the levee is unsaturated, and <br />the flow in unsaturated soils was taken into account* Unsaturated soils <br />typically have perrneabilities that are I to 3 orders of magnitude less than <br />saturated soils depending on degree of saturation. We assumed the <br />unsaturated permeability was on the order of 'I ftlyr for seepage analysis. <br />.. The levee may be subject to flooding or earthquake loads <br />at some time during its life. The 100-year flood level and hydrograph data <br />supplied by Leonard Rice Consulting Water Engineers, Inc. were used to <br />construct the hydrograph shorn in Fig. 15, which was input as boundary <br />conditions in the gootehnial analysis of the flood condition. The State of <br />Colorado recommends a minimum pseudo- static load coefficient of 0.05 g <br />FLATIRON COMPANIES <br />LEVEE AT DEEFE FARM PIT <br />CT LIT 25,385 <br />