A proposed fill is to be placed on the soil profile shown in Figure 3.9. A consolidation test has been performed on a sample obtained from Point A, and this test indicates the preconsoli- dation pressure at that point is 200 kPa. Determine whether the silty clay stratum is normally consolidated or overconsolidated, and compute the o solidation ratio. The proposed fill has not yet been placed. Povercon- # Hint: Determine EFFECTI E STRESS ATA water > Tevel 12m Silty Y = 19.1 kNhm :1.0m Sand (SM): Y =202 kNm 20 M Silty Clay (CL) Y=17.8 kN/m Figure 3.9 Soil profile for Example 3.3.

A proposed fill is to be placed on the soil profile shown in Figure 3.9. A consolidation test has been performed on a sample obtained from Point A, and this test indicates the preconsoli- dation pressure at that point is 200 kPa. Determine whether the silty clay stratum is normally consolidated or overconsolidated, and compute the o solidation ratio. The proposed fill has not yet been placed. Povercon- # Hint: Determine EFFECTI E STRESS ATA water > Tevel 12m Silty Y = 19.1 kNhm :1.0m Sand (SM): Y =202 kNm 20 M Silty Clay (CL) Y=17.8 kN/m Figure 3.9 Soil profile for Example 3.3.

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 11.3P

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Similar questions

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.
The figure below shows the soil profile at a site where you plan to lower the water table. You have results from two consolidation tests, one from the upper 12 ft thick overconsolidated crust, and another from the lower 40 ft thick normally consolidated zone. You plan to lower the water table from its current 12 ft depth to 25 ft below ground surface. The consolidation properties for each layer are shown. (Assume that changes in GWT do not affect γt of clay). a. Compute the σ′v in the middle of each layer before and after the water table is lowered b. Determine the total settlement that will result from lowering the water table
Refer to the soil profile shown in Figure P2.12. The clay is normally consolidated. A laboratory consolidation test on the clay gave the results: If the average effective stress on the clay layer increase by 50 kN/m2.a. What would be the total consolidation settlement?b. If Cv = 9.36 x 10-4 cm2/sec, how long will it take for half the consolidation settlement to take place?
Laboratory tests on a 25-mm-thick clay specimen drained at the top and bot-tom show that 50% consolidation takes place in 8.5 min.a. How long will it take for a similar clay layer in the field, 3.2 m thick anddrained at the top only, to undergo 50% consolidation?b. Find the time required for the clay layer in the field described in part (a)to reach 65% consolidation.
A 20 mm-thick sample in a singly drained laboratory consolidation test reaches 75% consolidation in 5 houres . How long will it take to reach 75% consolidation for a 5 m-thick clay sandwiched between two sand layers in the field ?
A clay sample was consolidated in a triaxial cell under a backpressure of 50 kPa and cell pressure of 150 kPa. The drainage valve was then closed and the cell pressure was increased to 200 kPa when the pore pressure increased to 98 kPa. What is Skempton’s B-parameter? The above sample was then subjected to a vertical deviator stress, which was increased from zero under undrained conditions. The sample failed when the pore water pressure was 160 kPa and the deviator stress was 70 kPa. What is Skempton’s A-parameter at failure? Assuming the clay is normally consolidated, find the friction angle in terms of effective stresses.
The following figure show the relationship between the voids ratio and effective stress for a soil sample collected from the mid depth of a 6 m thick clay layer. The Cc and Cr values have been determined to be 0.3 and 0.04 respectively. For the given information: If the current effective stress at the mid depth is 70 kPa, calculate the ultimate consolidation settlement when the effective stress at mid depth increases by 10 kPa due to an applied load. If the coefficient of consolidation is 0.555 m2/s and the clay layer is single drained, calculate the time taken to reach 45% consolidation.
A clay soil tested in a consolidometer showed a decrease in void ratio from 0.9 to 0.8 when the pressure was increased from 0.2 to 0.45 kgf/cm2. If the coefficient of consolidation (cv) determined in the test for the given stress increment was 10 m2/year, Calculate the coefficient of permeability in cm/sec.
A sand sample having specific gravity of 2.7 has a saturated unit weight of 20 KN/m². Determine it void ratio.
In a consolidated drained tri-axial text on a normally consolidated clay soil, a deviator of 152 kPa was required to fail the sample when the confining pressure was 70 kPa. A. What was the angle of shearing resistance? B. Suppose that after consolidation under the 70 kPa confining pressure, the sample is placed in an unconfined compression apparatus and tested. Determine the resulting shear strength.
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