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Cork Institute of Technology Bachelor of Engineering (Honours) in Structural Engineering - Stage 1
(Bachelor of Engineering in Structural Engineering – Stage 1) (NFQ Level 8)
(Time: 3 Hours)
Instructions: Attempt five questions This paper contains seven questions All questions carry equal marks Take g = 9.81 m/s2
Examiners: Mr. T. Corcoran Prof. P. O’ Donoghue Mr. B. O’ Rourke
Q. 1 The hinged plate shown in Figure Q. 1 has a uniform mass of 15kg and measures
0.7m x 0.45m. The tension in the supporting cable AB is 143.4 N. Determine the
moment due to this tension force about the origin, O.
Orthogonal x, y, z axes are in accordance with the right-hand rule, with origin, O as
indicated in the figure.
Q.2 The plane pin-jointed framework shown in Figure Q. 2 is supported by a pin at A and
a roller at D. The framework is subjected to a combination of vertical and horizontal
loads applied at the joints as indicated. Determine the support reactions. Use the
method of joints to calculate the forces in the members.
Indicate on a neat sketch of the framework the magnitude (kN) and type (tensile or
compressive) of each member force.
Q. 3 The beam shown in Figure Q. 3 is supported by a pin at A and a roller at C. The beam
is subject to a uniformly distributed load of 12 kN/m vertically along its full length
along with two additional vertical point loads of 12 kN and 9 kN as indicated in the
figure. Determine the reactions at A and C. Draw the shear force and bending moment
diagrams for the beam noting all significant values.
Q. 4 Fresh water in a channel is contained by a uniform 2.5m plate as shown in
Figure Q. 4. The plate is hinged at point A. Determine the weight of the gate (as
newtons per metre length of horizontal length into the paper) in order that it will open
when the water level reaches 0.9 m.
The density of fresh water may be taken as 1000 kg/m3.
Q. 5 A 4.0 m high square concrete column of cross-section 400mm x 400mm is reinforced
axially with 6 no. 20 mm diameter high tensile steel reinforcing bars. The applied load
acting axially on the column is 2500 kN in addition to its self-weight. Determine the
stresses in the concrete and the steel for the total load acting on the column. Determine
also the amount by which the column will shorten under this total load. You may
disregard the weight of the steel reinforcement.
Young’s modulus for concrete = 27 kN/mm2
Young’s modulus for steel = 205 kN/mm2
Unit weight of concrete = 24 kN/m3
Q. 6 A rock is allowed to fall from the edge of a cliff that is 122.5m high. Determine (a) its
velocity after 3 seconds, (b) the distance it will have travelled after 3 seconds, (c) the
length of time it takes for the rock to reach the base of the cliff, and (d) its velocity on
reaching the base of the cliff.
Q. 7 A pile driver with a mass of 1000 kg is set to fall freely through a distance of 5.0m
before striking a precast concrete pile of mass 500 kg. When the pile is almost fully
driven, the average resistance is 700 kN. Determine a) the striking velocity of the pile
driver, b) the common velocity of the pile driver and pile immediately after impact, c)
the penetration per blow at that stage and, d) the loss of kinetic energy at impact.