Principles of Foundation Engineering (MindTap Course List)
8th Edition
ISBN: 9781305081550
Author: Braja M. Das
Publisher: Cengage Learning
expand_more
expand_more
format_list_bulleted
Concept explainers
Question
Chapter 2, Problem 2.19P
To determine
Calculate the settlement at
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solutionStudents have asked these similar questions
2. A layer of compressible clay 6m thick overlies an impervious bedrock and carries an
overburden of pervious sand. A large structure founded in the sand causes the stress on every
horizontal section of the clay to increase to the same value.
In a standard laboratory oedometer consolidation test performed on a 19 mm thick clay
specimen, the void ratio changed from 0.765 to 0.750 under a corresponding increase in
stress. Consolidation was 70% complete after 30 min.
In the field,
a) Estimate the settlement of the structure.
b) Determine the time taken for one half of the consolidation settlement to take place
(Remember the lab test is for a doubly drained specimen.).
c) Determine how long it takes for 50% of the settlement to take place at a depth of 0, 2, 3,
5 and 6 m of the clay stratum.
d) If the clay were underlain by pervious sand, determine how long it takes for 50% of the
settlement to take place at a depth of 0, 2, 3, 5 and 6 m of the clay stratum.
A consolidated-undrained triaxial compression test was performed on a normalconsolidated clay sample. During the experiment, the confining pressure was 140 kPa, thedeviator stress was 125 kPa, and the pore water pressure was 75 kPa at the time of failure.According to the information given:i- Find the consolidated-undrained internal friction angle of the clay. ii- Find the drained friction angle of the clay
Refer to the soil profile shown in figure below. A laboratory consolidation test on the clay gave
the results:
o'c = 100 kPa
Cc = 0.4
Cs = 0.2Cc
If the average effective stress on the clay layer increases by 60 kN/m², what would be the total
consolidation settlement in cm.
Dry sand; e = 0.55 G,= 2.66:
Sand G₂ = 2.66 e = 0.48.
Clay w 34.78% G₂ = 2.74
Rock
1.5 m.
5 m
Water table;
Chapter 2 Solutions
Principles of Foundation Engineering (MindTap Course List)
Ch. 2 - Prob. 2.1PCh. 2 - Prob. 2.2PCh. 2 - Prob. 2.3PCh. 2 - Prob. 2.4PCh. 2 - Prob. 2.5PCh. 2 - Prob. 2.6PCh. 2 - Prob. 2.7PCh. 2 - Prob. 2.8PCh. 2 - Prob. 2.9PCh. 2 - Prob. 2.10P
Ch. 2 - Prob. 2.11PCh. 2 - Prob. 2.12PCh. 2 - Prob. 2.13PCh. 2 - Prob. 2.14PCh. 2 - Prob. 2.15PCh. 2 - For a normally consolidated soil, the following is...Ch. 2 - Prob. 2.17PCh. 2 - Prob. 2.18PCh. 2 - Prob. 2.19PCh. 2 - Prob. 2.20PCh. 2 - Prob. 2.21PCh. 2 - Prob. 2.22PCh. 2 - Prob. 2.23PCh. 2 - Prob. 2.24PCh. 2 - Prob. 2.25PCh. 2 - Prob. 2.26PCh. 2 - Prob. 2.27P
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, civil-engineering and related others by exploring similar questions and additional content below.Similar questions
- A saturated clay sample in an oedometer is under vertical pressure of 120 kPa and is at a normally consolidated state. The void ratio and the sample height at this stage are 1.21 and 18.40 mm respectively. When the vertical stress was increased to 240 kPa at the end of the consolidation, the thickness of the sample was reduced to 16.80 mm. When the vertical pressure was reduced to the original value of 120 kPa, the sample heaved to a thickness of 16.95 mm. Estimate both the compression index and recompression index of the clay. What would be the reduction in thickness from now if the vertical pressure was increased by 200 kPa? What is the average coefficient volume compressibility during this pressure increment?arrow_forwardA consolidated undrained triaxial test was performed on a normally consolidated clay with a critical state friction angle of 230. After an initial isotropic consolidation at a cell pressure of 50 kPa, drainage was turned off, the cell pressure was increased to 85 kPa, and the sample was loaded to ultimate conditions. A pore pressure of 55 kPa was measured at ultimate state. What value of major principal total stress was measured at the ultimate state?arrow_forwardA given saturated clay is known to have effective strength parameters of c' = 10 kPa and = 28°. A sample of this clay was brought to failure quickly so that no dissipation of the pore water pressures %3D could occur. At failure it was known that o KPa, o = 10 KPa and = 20 kPa. %3D (a) Estimate the values of o, and oz at failure (b) Use the Mohr circle to illustrate the effective stress and total failure stress.arrow_forward
- 4) In a oedometer test a specimen of a saturated clay 21 mm thíck reaches 50% consolidation in 10 minutes. How long would it take a layer of this clay 6 m thíck under the same drainage conditions to reach 90% f consolidation under the same stress and drainage conditions? Use the following relationships between the average degree of consolidation, U and time factor, T,: U =T, for Us 50% U =1-- for U>50% No need for calculation, please write only the results.arrow_forwardA standard oedometer test in the laboratory indicated that a 0.02 m thick clay specimen took 0.5 days to undergo 90% primary consolidation. How many days will a 2 m thick layer of identical clay sandwiched between sand layers and subjected to an identical stress increment take to undergo the same?arrow_forwardRefer 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?arrow_forward
- 1. The pressure versus void ratio data determined from a consolidation test on an undisturbed clay specimen are as follows: Applied Pressure (kPa) 20 40 80 160 320 640 1280 320 80 20 0 Void Ratio 0.953 0.948 0.938 0.920 0.878 0.789 0.691 0.719 0.754 0.791 0.890 (a) Plot this pressure versus void ratio data on a semi-logarithmic graph. (b) Determine the equations for the virgin compression curve and for the rebound curve for unloading starting at 1,280 kPa. (c) What are the corresponding compression and recompression indices for this soil? (d) Estimate the stress to which this clay has been preconsolidated. (After A. Casagrande.)arrow_forwardTable 1 given below presents the results of a conventional oedometer consolidation test conducted on a saturated clay sample with an initial height (thickness) and void ratio of H, = 20 mm and e, = 0.866, respectively. (a) Plot the consolidation curve in the semi-logarithmic space of void ratio and effective stress (or e-logo'). Determine the compression index C., recompression index C, and swell/rebound index C,. (b) Determine the past maximum effective stress (or pre-consolidation pressure) using the (maximum curvature) graphical method. (c) Determine the coefficient of compressibility m, for each of the loading/unloading stages. (d) Using the data provided in Table 2, which shows the relationship between displacement and time for the loading stage 160 kPa → 320 kPa, determine the coefficient of consolidation C, (using both methods discussed in the class) and the coefficient of permeability k for this loading stage. Table 2 Time, t (min) | Displacement, d (mm) Table 1 0.389 0.10…arrow_forward30. A fully saturated clay specimen is subjected to a pressure of 160 kPa in the consolidation test. After a period of time when the average pore pressure is 40 kPa, the degree of consolidation isarrow_forward
- 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]arrow_forwardAn 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.arrow_forwardData from an oedometer test using a clay specimen are plotted in the graph shown below. If the compression index is equal to 0.6, calculate the void ratio (e2) missing at Point C, which is associated with a vertical effective stress equal to 105 kPaarrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
- Principles of Geotechnical Engineering (MindTap C...Civil EngineeringISBN:9781305970939Author:Braja M. Das, Khaled SobhanPublisher:Cengage LearningFundamentals of Geotechnical Engineering (MindTap...Civil EngineeringISBN:9781305635180Author:Braja M. Das, Nagaratnam SivakuganPublisher:Cengage LearningPrinciples of Foundation Engineering (MindTap Cou...Civil EngineeringISBN:9781337705028Author:Braja M. Das, Nagaratnam SivakuganPublisher:Cengage Learning
Principles of Geotechnical Engineering (MindTap C...
Civil Engineering
ISBN:9781305970939
Author:Braja M. Das, Khaled Sobhan
Publisher:Cengage Learning
Fundamentals of Geotechnical Engineering (MindTap...
Civil Engineering
ISBN:9781305635180
Author:Braja M. Das, Nagaratnam Sivakugan
Publisher:Cengage Learning
Principles of Foundation Engineering (MindTap Cou...
Civil Engineering
ISBN:9781337705028
Author:Braja M. Das, Nagaratnam Sivakugan
Publisher:Cengage Learning