### Soil Mechanics - Compressibility of Soil, Consolidation & Compaction

1. The virgin compression curve for a particular soil is shown in the given figure. The compression index of the soil is
(a) 0.35
(b) 0.50
(c) 1.0
(d) 1.5 (IES 1994)
Hint: 2. When a stress is applied to a saturated soil, its volume reduces and effective stress
(a) decreases
(b) increases
(c) remains unaltered
(d) first decreases then increases

3. Compressibility of a soil sample decreases as the effective stress
(a) increases
(b) decreases
(c) first decreases then increases
(d) none of these

4. The slope of void ratio(e) versus effective stress plot is called
(a) compression index
(b) coefficient of compressibility
(c) coeff. of permeability
(d) coeff. of compressibility

5. In a soil sample if void ratio decreases with increases with stress, coefficient of compressibility will be
(a) positive
(b) negative
(c) any sign
(d) none of these

6. In a soil sample, with increase in effective stress, coefficient of compressibility
(a) decreases
(b) increases
(c) remains unchanged
(d) any of these

7. The void ratio-pressure diagram is shown in the given figure. The coefficient of compressibility is

(a) 0.0050 m²/t
(b) 0.073 m²/t
(c) 0.20 m²/t
(d) 0.25 m²/t (IES 1995)
Hint: 8. The e-p curve for a soil is shown in the above figure. The coefficient of compressibility(in m²/kN) of the soil is
(a) 4000
(b) 2000
(c) 2.5 x 10⁻⁴
(d)  1.25 x 10⁻⁴ (IES 2001)

9. Match List I(Property) with List II(Slope of the curve) and select the correct answer using the codes given below the lists:
List I
A. Coefficient of compressibility
B. Compression index
List II
1. Stress - deformation
2. Stress - void ratio
3. Volume - pressure
4. Log stress - void ratio
(a) A4,B2,C1
(b) A4,B3,C2
(c) A2,B4,C1
(d) A3,B4,C1 (IES 1996)

10. Terzaghi’s theory relates settlement with
(a) excess pore water pressure
(b) depth below the top clay layer
(c) time from the instantaneous application of a total stress increment
(d) all of the above

1. (b)    2. (b)    3. (a)    4. (d)    5. (b)
6. (a)    7. (c)    8. (c)    9. (c)    10. (d)

---
These questions are taken from the book "Objective Questions (Civil Engineering)". The Kindle edition of this book is available at just ₹ 99/- only!