Shear Box Test Calcs Flashcards
How is the area of shear box calculated?
What are the typical dimensions and therefore the typical area?
Normally square, so one length squared or length x length
60mm x 60mm = 3600mm
What units should the area of the shear box be in?
What conversion factor is needed?
m^2
Divided by (1000 x 1000)
If the normal load is given in kg, how is it converted to newtons?
What units should the load be in? How is it converted to a these units?
How are the normal and shear loads converted to stresses?
x 9.81
Should be in kN, x 10 ^ -3
/ area of shear box (m^2)
When plotting the graph, which values are plotted on which axis?
X axis = normal stress
Y axis = shear stress at failure
What scale should the axis be drawn to?
1:1, each axis should be done to the same scale
After plotting the points, what must be done?
A line of best fit must be drawn, from this, the cohesion can be obtained and the angle of frictional resistance
How is cohesion obtained?
It will be the y-intercept point of the failure envelope
How is angle of frictional resistance obtained?
Measured using a protractor from the horizontal to the line of best fit
What units are given for cohesion, C?
kN/m^2
