Question 05 A site has a level ground surface and a level groundwater table located 5 m below the ground surface, as shown in figure. The average void ratio of the clay layer is 1.10 and the saturated unit weight of the clay layer is 7.9 kN/m3. The unit weight of the sand above the ground water table is 18.7 kN/m3 and the saturated unit weight of the sand below the groundwater table is 19.7 kN/m3. A laboratory consolidation test performed on an undisturbed specimen obtained from the center of the clay layer indicated 100 kPa as the maximum past pressure and 0.83 as the compression index. Caclulate the primary consolidation settlement below 2 m thick clay layer if a uniform fill surcharge of 50 kPa is applied over a very large area at ground surface. Fill surcharge 50 kPa g.s. Sand 5 m g.w.t. 5 m 2 m Sand E

Question 05 A site has a level ground surface and a level groundwater table located 5 m below the ground surface, as shown in figure. The average void ratio of the clay layer is 1.10 and the saturated unit weight of the clay layer is 7.9 kN/m3. The unit weight of the sand above the ground water table is 18.7 kN/m3 and the saturated unit weight of the sand below the groundwater table is 19.7 kN/m3. A laboratory consolidation test performed on an undisturbed specimen obtained from the center of the clay layer indicated 100 kPa as the maximum past pressure and 0.83 as the compression index. Caclulate the primary consolidation settlement below 2 m thick clay layer if a uniform fill surcharge of 50 kPa is applied over a very large area at ground surface. Fill surcharge 50 kPa g.s. Sand 5 m g.w.t. 5 m 2 m Sand E

Principles of Geotechnical Engineering (MindTap Course List)

9th Edition

ISBN:9781305970939

Author:Braja M. Das, Khaled Sobhan

Publisher:Braja M. Das, Khaled Sobhan

Chapter11: Compressibility Of Soil

Section: Chapter Questions

Problem 11.16P

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Q1: A clay specimen was tested in a laboratory consolidation device, which was 12.7 mm thick and the top & bottom boundaries were drained. A 50% consolidation time on the specimen was obtained as 28.4 minutes, Determine the Following: a- The time for 50% consolidation in the field with a 2.5 m thickness where ‘only the top layer is drained. b- The time for 90% consolidation in the field with a 2.5 m thickness where only the top layer is drained. c- For the same field condition above, find the settlement after 1year, if the final consolidation settlement = 0.0345 m.
A 3.75m clay layer in the field (drained on one side) is normally consolidated. When the pressure is increased from 50 kPa to 150 kPa, the void ratio decreases from 0.9 to 0.75. The coefficient of permeability of the clay was 6 x 10^-7 cm/s.• How long (days) will it take to reach 50% consolidation?• What is the settlement when the soil reaches 50% consolidation?Final answer should be in 3 decimal places.
Yes A site has a level ground surface and a level groundwater table located 5 m below the ground surface. As shown in Fig., subsurface exploration has discovered that the site is underlain with sand, except for a uniform and continuous clay layer that is located at a depth of 10 to 12 m below ground surface. Below the groundwater table, the pore water pressures are hydrostatic in the sand layers (i.e., no artesian pressures). The average void ratio e of the clay layer is 1.10 and the buoyant unit weight γ of the clay layer = 7.9 kN/m3 . The total unit weight γ of the sand above the groundwater table = 18.7 kN/m3 and the total unit weight γ of the sand below the groundwater table = 19.7 kN/m3 . A laboratory consolidation test performed on an undisturbed specimen obtained from the center of the clay layer (Point A, Fig) indicates the maximum past pressure σ′ = 100 kPa and the compression index C = 0.83. Determine the primary consolidation settlement s of the 2 m thick clay layer if a…
A 3-m thick layer of saturated clay (two-way drainage) under a surcharge loadingunderwent 90% primary consolidation in 100 days. The laboratory test’s specimenwill have two-way drainage.a. Find the coefficient of consolidation of clay for the pressure range. b. For a 25 mm. thick undisturbed clay specimen, how long will it take to under-go 80% consolidation in the laboratory for a similar pressure range?
A clay sample underwent a consolidation test in the lab. The clay specimen has drainage on both sides and a height of 25.4 mm. Assume that the clay sample's preconsolidation pressure was less than 150 kPa prior to the consolidation test. The void ratio was 0.96 when the applied effective vertical pressure was 150 kPa. When the vertical effective pressure increased from 150 to 220 kPa, the void ratio at the end of consolidation and compression was 0.88. It was discovered that the sample needed 3 minutes to consolidate by 30%. Following the consolidation test, a swelling/unloading test was conducted, in which the vertical effective stress was lowered from 220 to 150 kPa and the end-of-swelling void ratio was determined to be 0.9. Required a. The compression index of the clay b. The swelling index of the clay C. The height of the clay sample at the end of compression d. The coefficient of consolidation of the clay e. The final height of the clay sample at the end of swelling
A sand sample having specific gravity of 2.7 has a saturated unit weight of 20 KN/m². Determine it void ratio.
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1. A soil sample has a maximum void ratio of 0.85 and minimum void ratio of 0.55. It was also found out that the porosity is 23%, moisture content is 12% and Gs = 2.65. Compute the dry unit weight of the sample. 2. Estimate the compression index of soft clay with moisture content of 56.4 percent. The liquid limit is 56 percent.
Figure below shows a soil profile. The uniformly distributed load on the ground surface is Δσ. 2Given Δσ = 150 kN/m , compression index (Cc) for clay layer is 0.30, and recompression index (Cs) for clay layer is 0.06. Estimate the primary consolidation settlement if the clay is normally consolidated (NC).Given:H1 =2.5m,H2 =2.5m,andH3 =3.5m.Sand: γdry(sand) = 15 kN/m3; γsat(sand) = 18 kN/m3 Clay: γsat(clay) = 19 kN/m3; Initial void ratio for clay, e0 = 0.65
A sample of silty clay has a volume of 14.88 cm3, a total weight of 28.81 gms, a dry weight of 24.83 gms and a specific gravity of 2.7. Determine the void ratio and the degree of saturation
The total density of sand in an embankment was found to be 1900kg/m^3 and the field water content was 12% . In the laboratory, the density of the solid was found to be 2660 kg.m^3, and the maximum and minimum voids ratio were 0.63 and 0.44, respectively What is the void ratio of the sand? Calculate the relative density of the sand in the field: