Question: 5 (15 points) A plate-bearing test using a 30-inch diameter flexible plate was performed on a subgrade. The lo

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Question 5 15 Points A Plate Bearing Test Using A 30 Inch Diameter Flexible Plate Was Performed On A Subgrade The Lo 1 (199.17 KiB) Viewed 50 times

Question: 5 (15 points) A plate-bearing test using a 30-inch diameter flexible plate was performed on a subgrade. The load required to cause a 0.2-inch surface deflection at the center of the plate was 10 psi. A 15 inch layer of crushed stone was then placed on top of this subgrade and a plate bearing test was performed again (same flexible plate as before). The stress needed to cause a surface deflection of 0.2 inch on top of the crushed stone plus subgrade structure at the center of the plate was 35 psi. Calculate the modulus values of the subgrade and base layers? (assume p = 0.5 for all materials). Answer: a. One Layer Analysis (Only Subgrade), Surface Deflection w 015 F 02 0 04 05 06 07 08 09 10 20 -0.25 20 Numbers on curves indicate r/a /2 F 80 10 b. Two Layers Analysis (Base and Subgrade), Surface Deflection or at r= 0 and z=0 10 08 5 811 = 1.5qa E2 F2 DI 06 05 04 03 1 Two-layer deflection factors V 0.1 va E/E 0.08 Vos 006 0.05 0.04 003 0021 0 056 1.0 42 5a ба 150 2.05 Ja Thickness of reinforcing lyer multiples of radius of contact) h/a