shear stress
pore water pressure
direct bearing on effective normal stress because it can add or subtract to it
friction
loose packed with smooth surfaces slide easier past each other dense packed with rough surface have higher resitance to shear
shear strength
properties of matter that resist the stresses generated by gravitational force
coulomb equation for shear stress
s = c + ((delta n +- water pore pressure)* tan phi)
soil shear strength
saturated soil - fricitional strength reduced dry soil - medium moist - friction at max
effective normal stress
stress exerted at the solid to solid contacts across the shear surface delta n
coefficient of plane sliding friction
tan phi
shear strain
change of shape or volume produced by a stress
shear stress
body deforms by one part sliding over the other
normal stress
capacity to hold material together increasing the internal resistance to shear acts perpendicular to shear surface two elements: effective normal stress and pore water pressure
cohesion
caused by chemical cementation of rock and soil particles and electrostatic and electromagnetic forces