07A80107 Soil Dynamics & Machine Foundations B.Tech Question Paper : scce.ac.in

Name of the College : SREE CHAITANYA COLLEGE OF ENGINEERING
University : JNTUH
Department : Civil Engineering
Subject Code/Name : 07A80107/SOIL DYNAMICS AND MACHINE FOUNDATIONS
Year/Sem : IV/II
Website : scce.ac.in
Document Type : Model Question Paper

Download Model/Sample Question Paper : https://www.pdfquestion.in/uploads/scce.ac.in/4906-07A80107-SOILDYNAMICSANDMACHINEFOUNDATIONS.pdf

SCCE Soil Dynamics & Machine Question Paper

IV B.Tech II Semester Examinations,April/May 2012
Time: 3 hours
Max Marks: 80

Related : Sree Chaitanya College Of Engineering 07A80106 Pavement Analysis & Design B.Tech Question Paper : www.pdfquestion.in/4907.html

Set No. 1

Answer any FIVE Questions :
All Questions carry equal marks :
1. Describe the three principles which make the basis of seismic wave propagation theory. [16]
2. Explain mechanical isolation with neat sketch. [16]
3. Explain the analysis of a block foundation subjected to pure rocking vibration.[16]

4. Discuss the following:
(a) Under damped system,
(b) Critically damped system,
(c) Over damped system. [16]

5. (a) Explain how the natural frequency of foundation soil system is estimated using the Barken’s analysis and IS code method.

(b) In Pauw’s analysis, the base of the machine is 2 2 m, penetrating 1.5 m below ground level. If the amplitude of vibration is 0.03 mm, apply the reduction factor for embedment and determine the likely amplitude. [8+8]

6. Explain with neat sketches how the shear wave velocity of soil strata is estimated using seismic up hole, down hole and cross-hole techniques. [16]
7. Derive the expressions for frequencies and amplitude for the case of undamped free vibrations of a two degrees freedom system. [16]

8. A machine of mass, M = 500 kg is mounted on a simply supported steel beam of length, L = 2m having a rectangular section with depth of 0.1 m, width of 1.2 m and Young’s modulus, E = 2.06 1011 N/m2. To reduce the vertical deflection, of the beam, a spring of stiness k is attached as shown in Figure 1.

Determine the value of k needed to reduce the deflection of the beam by:
(a) 25% of its original value
(b) 50% of its original value
(c) 75% of its original value. [16]

Set No. 2

Code No: 07A80107
R07
1. (a) Why dynamic soil properties are evaluated? List the various laboratory and field tests for dynamic soil properties.

(b) A block vibration test was performed on a block made up of M15 grade concrete of size 1m x 1m x 1m using vertical excitation. The unit weight of concrete is 24 kN/m3. For the results given below, determine the coefficient of elastic uniform compression and the damping ratio.

Also, determine the coefficient of elastic uniform compression if the foundation base area is 9 m2. [8+8]
Frequency (rpm) 600 700 800 900 950 1100 1125
Amplitude (mm) 0.12 0.32 0.64 2.40 2.08 1.68 1.36

2. Describe the wave propagation in an infinite, homogeneous, isotropic and elastic medium. [16]
3. Discuss about the dynamic response of embedded block foundations. [16]

4. Discuss Tschebotario’s reduced natural frequency. Describe the factors affecting coefficient of elastic uniform compression. [16]
5. Write in detail on modeling of machine foundation. [16]

6. An electric motor of mass 60 kg, rated speed 3000 rpm and an unbalance of 0.002 kg-m, is to be mounted on an isolator to achieve a force transmissibility of less than 0.25. Determine
(a) Stiness of the isolator
(b) Dynamic amplitude of the motor and
(c) The force transmitted to the foundation. [16]

7. Starting from fundamentals, obtain the equations of motion for over damped, critically damped and under damped systems and discuss their eect on amplitude of vibration. [16]
8. Obtain the necessary expressions for frequencies and amplitudes for the case of forced vibrations of a two degrees freedom system. [16]

Set No. 3

Soil Dynamics And Machine Foundations :
1. Describe the three principles which make the basis of seismic wave propagation theory. [16]
2. Explain mechanical isolation with neat sketch. [16]

3. Explain the analysis of a block foundation subjected to pure rocking vibration.[16]
4. Discuss the following:
(a) Under damped system,
(b) Critically damped system,
(c) Over damped system.

5. (a) Explain how the natural frequency of foundation soil system is estimated using the Barken’s analysis and IS code method.

(b) In Pauw’s analysis, the base of the machine is 2 2 m, penetrating 1.5 m below ground level. If the amplitude of vibration is 0.03 mm, apply the reduction factor for embedment and determine the likely amplitude. [8+8]

6. Explain with neat sketches how the shear wave velocity of soil strata is estimated using seismic up hole, down hole and cross-hole techniques.