Question

NAME: Extra Credit. Design a graded granular filter to protect Soil "A". The gradation of Soil "A" is shown in the figure and has a dio of 0.02 mm, dis of 0.03 mm, a dso of 0.15 mm, a deo of 0.2 mm and a das of 1.0 mm. The soil will be placed at a relative density of 70%. There will also be a slotted pipe having slot widths of 6.4 mm (o.25 in) used within the drain system. Draw the "Acceptable Range for a Good Filter" on the grain size plot. Also determine an equivalent AOS (Oss) for a geotextile that could be used instead of a graded granular filter. (10 points) Grain Size Analysis Sals Eine U S Standard Sieve No e 200 1004000 90 80 70 30 20 i0 I0 lou Grain Size (m)

Answer 1