Jawaharlal Nehru Technological University Hyderabad 2007 B.E Civil Engineering SOIL DYNAMICS AND MACHINE FOUNDATION-set4 - Question Paper

1. (a) elaborate the safe bearing pressures and how are they arrived at? [8]
(b) define the different kinds of machine foundations. [8]
2. Starting from fundamentals, find the equations of motion for over damped, crit-
ically damped and under damped systems. [16]
3. (a) Out line Barken?s method for finding natural frequency. [6]
(b) A machine weighing 100kg is supported directly on springs having a stiffness of
200kg/m. The unbalanced rotating mass outcomes in a disturbing force of 20kg
at a speed of 3000r.p.m. The damping factor is 0.1. Determine the amplitude
of vibration and the force transmitted to the foundation. [10]
4. (a) Why is vibration isolation needed [8]
(b) What do you understand by active isolation and passive isolation. [8]
5. elaborate the laboratory methods used to determine the dynamic properties of
soils? discuss them in brief. [16]
6. (a) discuss the step by step. procedure of pauw?s analogy. [8]
(b) In Pauw?s analysis, the base of the machine is two × 3.5 m, penetrating 1
m beneath ground level. If the amplitude of vibration is 0.002 cm, apply the
reduction factor for embedment and determine the likely amplitude. [8]
7. (a) How do you analyse a block foundation based on elastic half-space theory? [8]
(b) discuss Quinlan and Sung’s changes. [8]
8. discuss in detail the I.S.code method of design of hammer foundation. [16]

Earning:   Approval pending.