A 4.0m long steel, beam with a cross-sectional area of 1.0 x10-2m² and a young's modulus of
2.0 x1011 N/m2 is wedged horizontally between
two vertical walls. In order to wedge the beam,
it is compressed by 0.020mm. If the coefficient
of static friction between the beam and the walls
is 0.70 the maximum mass (including its own) it
can bear without slipping is :
(1) O
(2) 3.6kg
(3) 36kg
(4) 710kg

A5 foot by 5 foot box culvert is buried 6 feet beneath the surface of the ground. a crosssection of this very long culvert (into and out of the page) is illustrated below. assume that the soil in which the culvert is buried has the following properties: jt = 120 pcf, w = 12%, ko = 0.50, ka = 0.33, and kp = 3.00. calculate the total horizontal force per unit length of culvert (fh) felt on one of the vertical faces of the culvert.