300+ TOP SOIL MECHANICS LAB VIVA Questions and Answers

SOIL MECHANICS LAB VIVA Questions :-

1. What Is Meant By Elastic Limit?

The maximum extent to which a solid may be stretched without permanent alteration of size or shape.

2. State The Applications Of Modulus Of Elasticity?

Modulus of elasticity is related to the flexibility of the material. The value of modulus of elasticity is pretty important in case of deflection of different materials used in building construction.

3. What Is Meant By Poisson Ratio?

Poisson’s ratio, named after Siméon Poisson, is the negative ratio of transverse to axial strain. When a material is compressed in one direction, it usually tends to expand in the other two directions perpendicular or parallel to the direction of flow.

4. What Is Punching Shear?

Punching shear is a type of failure of reinforced concrete slabs subjected to high localized forces. In flat slab structures this occurs at column support points.

5. The Standard Sand Now A Day’s Used In India Is Obtained From?

Ennore (madras)

6. What Is Soil Analysis?

Soil analysis is the testing of soil to determine the nutritional and elemental composition of soil. It is generally tested for knowing the contents of nitrogen, potassium and phosphorus.

7. What Is The Difference Between Sill Beam, Tie Beam And Plinth Beam?

• Sill beam: – flexural member
• Tie beam: – fully compression member
• Plinth beam: – loading from bottom (soil mass) is UDL so
• Main reinforcement is in top of beam.

8. The Foundation In Which A Cantilever Beam Is Provided To Join Two Footings, Is Known As?

Strap footing

9. The Foundations Are Placed Below Ground Level, To Increase?

Strength
Work ability
Stability of structure

10. What Are The Causes Of Failure Or The Error Made In The Design Of The Failed Wall Is?

The main reason of failure of a wall is overturning.

11. What Is The Difference Between Grade Beam And Plinth Beam?

Plinth beam is a part of a structure can transfer loads to the adjacent columns, grade beam is a type of foundation system used to distribute the weight of a building over unstable soil. The grade beam may sit directly on the loose soil.

PERMEABILITY TEST :

1) List ‘k’ values for different types of soils.
2) How permeability test is done in the field?
3) Mention other permeability tests that can be done in the lab.
4) What is the application of permeability of soils?
5) Derive the expression for ‘k’ by falling head method.
6) Is hydraulic gradient constant in variable head test? Why?
7) How will you reduce observed permeability to permeability at standard temperature?
8) What is the necessity of two methods for determination of ‘k’ in lab?
9) Estimate discharge velocity in constant head test conducted. What is seepage velocity?
10) Time interval for flow from h1 to h0 should be same as that from h0 to h2. Why?

FIELD DENSITY –SAND REPLACEMENT METHOD (IS 2720 PART XXVIII-1974)

11) Depth of hole made in field is limited to 15 cm.Why?
12) Explain core cutter method for determination of in-situ density of soil.
13) Explain the significance of in-situ density soil density determination.

COMPACTION TEST (IS 2720 PART VII-1974)

14) What is the approximate value of degree of saturation at OMC?
15) How does amount of compaction affect maximum dry density and OMC?
16) What is the procedure for conducting modified proctor test?
17) What is the use of proctor’s needle? How is it used for compaction control in the field?
18) Explain how soil compaction is achieved?

CALIFORNIA BEARING RATIO TEST

19) How correction for initial concavity is done in load-penetration curve?
20) What is the application of CBR test results?
21) Write the procedure to find expansion ratios for a soaked test.
22) What is the need for adding surcharge weights?

CONSISTENCY LIMITS (IS 2720 PART V-1972, IS 9259-1979)

23) Draw plasticity chart and mark the soil tested and classify soil.
24) What is activity number?
25) Why clay exhibit plasticity while silt does not?
26) Indicate engineering uses of IP , IT , IL and IC
27) Is soil fully saturated at shrinkage limit?
28) Explain the one point method for liquid limit determination.
29) If the plastic limit is greater than or equal to liquid limit, how will you report IP of the soil?
30) If plastic limit can’t be determined for sandy soil, how will you report plasticity index?
31) Whether oven drying of sample before test is permitted? If not why?
32) Find compression index of given normally sensitive clay. What is the use of it?
33) How will you differentiate organic and inorganic soil using liquid limit test?

SOIL MECHANICS LAB VIVA Questions ::