The results of a consolidation test on an undisturbed soil, sampled at a depth of 10 m below the ground level are as follows: Saturated unit weight : 16 kN/m³ Pre-consolidation pressure : 90 kPa The water table was encountered at the ground level. Assuming the unit weight of water as 10 kN/m³, the over-consolidation ratio of the soil is

The results of a consolidation test on an undisturbed soil, sampled at a depth of 10 m below the ground level are as follows: Saturated unit weight : 16 kN/m³ Pre-consolidation pressure : 90 kPa The water table was encountered at the ground level. Assuming the unit weight of water as 10 kN/m³, the over-consolidation ratio of the soil is

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

See similar textbooks

Similar questions

Soil
The average effective averburden pressure on 10 m thick homogeneous saturated clay layer is 150 kPa. Consolidation test on an undisturbed soil sample taken from the clay layer showed that the void ratio decreased from 0.6 to 0.5 by increasing the stress intensity from 100 kPa to 300 kPa. (G = 2.65) %3D The initial void ratio of the clay layer is
Q.4(a)(i) A laboratory consolidation test on a normally consolidated clay showed the following results: Load, 3( kN/m²) 140 212 Void ratio, e 0.92 0.86 The specimen tested was 25.4 mm in thickness and drained on both sides. The time required for the specimen to reach 50% consolidation was 4.5 min. A similar clay layer in the field 2.8 m thick and drained on both sides is subjected to a similar increase in average effective pressure (i.e. 5o = 140 kN/m² and Jo + 40 = - 212 kN/m²). Determine (a) the expected maximum primary consolidation settlement in the field. (b) the time required for the total settlement in the field to reach 40 mm. [Assume uniform initial increase in excess pore water pressure with depth]
An oedometer test on a saturated clay soil gave the following results: Cc = 0.2 and Cs = 0.04. The in-situ vertical effective stress in the field is 130 kPa. A building foundation will increase the vertical stress in the center of the clay by 150 kPa. The thickness of the clay layer is 2 m and its water content is 28%. Calculate the primary consolidation settlement of the clay layer in the field if: a). OCR = 4.5; b). OCR = 1.5.
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 cylindrical water tank weighing 1,000,000 N with a diameter of 3.5 m is expected to be placed on a 5 m thick clay layer that is fully saturated. Unit weights of the saturated clay layer and water are 19.4 and 9.81 KN/m respectively. Consolidation tests performed from sample taken from midpoint of the layer was found to have the properties shown in table 2. Table 2 Preconsolidation Stress (kPa) Co Cr eo 17 40 0.26 0.05 0.44 a. What is the ultimate settlement expected in the clay layer due to the water tank? b. If 99 mm of settlements were observed after one year of placing the tank, what is the Cv of the clay layer? Assume clay is singly drained.
In the laboratory test on a clay sample of thickness 25mm, drained at top only, 50% consolidation occurred in 11 minutes. Assume = 0.197, T = 0.405. Find the time required for the corresponding clay layer in the field of 3m thick and drained at top and bottom to undergo 50% consolidation. Also, find the time required to undergo 70% consolidation. TE %3D 70 50
The water content of a sample of saturated soil at a mean effective stress of 10 kPa is 85%. The sample was isotropically consolidated with a mean effective stress of 150 kPa. At the end of the consolidation, the water content was 50%. The sample was then isotropically unloaded to a mean effective stress of 100 kPa, and the water content increased by 1%. Given: Gs = 2.7, o'cs = 25°. a) Calculate and K. 10 b) Determine the failure stresses (p'f and gf) under CU test and CD test for the conditions.
A site is underlain by a saturated clay layer with thickness = 5m. A sample extracted from the center of the clay layer was recently tested for consolidation parameters. The results indicate that the compression index is 0.33, the recompression index is 0.09, and the void ratio is 1.2. The results also indicate that the layer is normally consolidated. Calculate the preconsolidation stress of the clay. Express your answer in kPa. Note: this is a short problem; read the problem statement carefully. Use unit water weight = 10 kN/m3.
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
3. A consolidated undrained test on a normally consolidated clay yielded the following results: 7.2 psi Pore pressure: Chamber confining pressure: 15 psi 12 psi Calculate the consolidated-undrained friction angle and the drained friction angle. Deviator stress at failure:
A clay soil, tested in a consolidometer, showed a decrease in void ratio from 1.20 to 1.10 when the presure was increased from 0.25 to 0.50 kgf/cm². Calculate the coefficient of compressibility (a) and the coefficient of volume compressibility (m). If the coefficient of consolidation (c) determined in the test for the given stress increment was 10 m²/year, calculate the coefficient of permeability in cm/s. O ferd ses osis ass sno If the sample tested at the site was taken from a clay layer 3.0 m in thickness, determine the consolidation settlement resulting from the given stress increment.