Structural Analysis Multiple Choice Questions on “Loading Conditions for Allowable Stress Design”.
1. With the allowable stress method, which conditions are computed?
a) Most severe loading conditions and inelastic stresses
b) Most severe loading conditions and elastic stresses
c) Feeble loading conditions and inelastic stresses
d) Feeble loading conditions and elastic stresses
Answer: b
Clarification: This method computes most severe loading conditions and elastic stresses but appreciably below the ultimate stresses.
2. Allowable stress method considers which type of loadings?
a) Simultaneous
b) Non- simultaneous
c) Mixture of both
d) Only dead loads
Answer: a
Clarification: It considers simultaneous loading possibilities to determine most severe loading conditions.
3. Live load and roof live loads are represented by the same symbol.
State whether the above written statement is true or false.
a) True
b) False
Answer: a
Clarification: L represents live load, while Lr is used to represent roof live load.
4. Which of the following simultaneous loading conditions are not necessary to be considered for the most severe situations:-
a) D + F
b) D + H + F + L + T
c) D + H + F
d) 0.6D + W + H
Answer: c
Clarification: Necessary conditions are mentioned in Section 2 of ASCE 7-02. These can be matched from there.
5. With which loads are impact effects considered?
a) Rain
b) Snow
c) Live
d) Fluids
Answer: c
Clarification: Impact effects occur when live loads are quickly applied. So, they are considered with them only.
6. Which of the following load do not vary appreciably with time?
a) Snow
b) Dead
c) Rain
d) Wind
Answer: b
Clarification: There is never a permanent presence of snow on a structure, nor is that of rain and wind.
7. If a full dead load is not acting during an earthquake or a severe wind storm, then chances of overturning of building will:-
a) Decrease
b) Increase
c) Remain same
d) Depend upon case
Answer: b
Clarification: Earthquake and wind load acts in lateral direction, enhancing overturning. While, dead load acts in the vertical downward direction resisting overturning.
8. When two or more loads are acting on a structure in addition to dead load, then ASCE permits the loads other than dead loads to be multiplied by a factor of (provided the result is not less than that produced by dead load and the load causing greatest effect)
a) 0.60
b) 0.65
c) 0.70
d) 0.75
Answer: d
Clarification: In these conditions, most likely loads other than dead one do not achieve their maximum values simultaneously. This assumption is validated by load surveys.
9. In the above question, using factor of 0.75 is:-
a) Compulsory
b) Compulsory in some case
c) Depends upon the engineer
d) Depends upon loads
Answer: c
Clarification: Factor of 0.75 is only helping in listing the minimum conditions to be considered.