C.E. 321- W 96

Mid Term Exam 1

Feb. 5 - 9, 1995

_______________________ _____________________

Name Score

___________ _________ _____________________

Time Begin Time End Location

This exam is open book and open notes, however it must be an individual effort, no help can be sought or used from anyone else.

1. (14 points) Given the following structures, indicate whether they are stable or unstable

a)

b)

c)

for the trusses shown below, members are pin connected only where a is shown. The slanting members are not connected in d, f, and g where they cross.

d) e)

f) g)

2. (26 points) For the truss shown below, determine the influence lines for members Bb and bc.

B C

6 m

a b c d

6 m 6 m 6 m

3. (30 points) For the beam shown below

A) Develop influence lines for

the reaction at A,

the shear at point C (i.e. 8 ft to the right of A)

the moment at point C

the shear at point D ( i.e. 8 ft to the right of B).

the moment at point D.

(Specify the peak values on each diagram)

B) The beam is subjected to a uniform dead load of .8 k/ft, a uniform live load of 3 k/ft and a single concentrated live load of 15 kip. Show the placement of these loads on the beam to produce

The Maximum reaction at A,

the Maximum shear at point C (i.e. 8 ft to the right of A)

the Maximum moment at point C

the Maximum shear at point D ( i.e. 8 ft to the right of B).

the Maximum moment at point D.

C) For these loads, compute

The Maximum reaction at A,

the Maximum shear at point C (i.e. 8 ft to the right of A)

the Maximum moment at point C

the Maximum shear at point D ( i.e. 8 ft to the right of B).

the Maximum moment at point D

A C B D E

8 ft 8 ft

10 ft 30 ft 10 ft4) (30 points) Determine the absolute maximum live moment in the bridge due to the truck loading shown.

Show where these loads must be placed for this condition to prevail

Assume that the truck can travel in either direction.

8k 32k 32k

14 ft 14 ft

60 ft.