Find out the average resistance of the ground, Mechanical Engineering

Find out the average resistance of the ground:

In a construction of pile-driving for building, a pile driver of mass 25 kg freely drops through a height of 3 metre on the top of a pile having mass of 50 kg. If this is driven into the ground through 7.5 cm, find out the average resistance of the ground to pile driving and the amount of energy lost in impact.


WH   =  Weight of pile-hammer (driver) = 25 × g N

VH   = Velocity of driver before impact =

                                      2413_Find out the average resistance of the ground.png = 7.67 m / sec.

WP  = Weight of pile = 50 g N.

By Using principle of conservation of the momentum,

 (WH  VH )/g = ((WH + WP )/g) Vc

where, Vc is a common velocity of the pile along with hammer

∴ Vc  = 25 × 7.67 /75 = 2.56 m / sec.

Figure 8.7

Refer Figure showing ground resistance R

2157_Find out the average resistance of the ground1.png

R′ = Net upward resistance = R - WP  - WH

                                                = R - (75 g )

∴ (R - 75 g ) × 7.5 = ( (25 + 50) × (2.56)2/2

∴ R - 75 × 9.81 =75 × (2.56)2 /15

∴ R = 768.52 N

KE lost in impact = KE before impact - KE after impact

=25 × (7.67)2 / 2 -75 × (2.56)2 /2

= 735.36 - 245.76

= 489.60 N. m.

Posted Date: 1/29/2013 7:07:00 AM | Location : United States

Related Discussions:- Find out the average resistance of the ground, Assignment Help, Ask Question on Find out the average resistance of the ground, Get Answer, Expert's Help, Find out the average resistance of the ground Discussions

Write discussion on Find out the average resistance of the ground
Your posts are moderated
Related Questions
Define stress: Sol.: When body is acted upon by load or external force, it undergoes deformation (that is, change in shape or dimension) which increases gradually. At the ti

Functions of the Piston To transmit force of explosion to the crankshaft. To form a seal so that high pressure gases from the combustion chamber do not escape into th

a compound cylinder is composed of a tube of 250mm internal diameter at 25mm wall is shrunk on to a tube of 200mm internal diameter. the radial pressure at the junctio

(a) Show that the force exerted by a jet of water on an inclined fixed plate in the dissection of jet is given by fx = .a.v 2 . sin 2 θ. Where a is area of jet, v is velocity of j

Project is about Heat exchanger kit named TE 93.....Project guide has told us to do something with it..without modifying the project largely.....i came up with change of material o

how to find bending moment diagram of cantilever beam.any formula

Construction of Lacashire boiler: CONSTRUCTION : Consists of boiler shell which contains water and steam. Diameter can vary from 1.75 to 2.75 m and length can be 7.25 - 9 m

The auto component sector has also posted significant growth of 20 percent in 2003-04, and achieved a sales turnover of Rs. 30,640 crore (US$ 6.7 billion). Further, there is a pote

How CAD system communicate with control system The concept of a universal data exchange system is depicted in figure. In this figure, it is shown how various CAD systems commun