250+ TOP MCQs on Equivalent Lateral Force Procedure for Estimating Seismic Loads-2 and Answers

Structural Analysis Questions and Answers for Freshers on “Equivalent Lateral Force Procedure for Estimating Seismic Loads-2”.

This figure is used in question 1-6.

The figure above shown is an incomplete diagram of a hospital consisting of reinforced concrete frames with rigid joints. Given that S_DS = 1.2g and S_DI = 0.5 g and w= 400k.

1. Find the fundamental natural period of this building?
a) 1.175
b) 1.275
c) 1.375
d) 1.475
Answer: c
Clarification: T_a = C_t h_n^x, C_t will be 0.02, x will be 0.9 and h_n will be 110 ft.

2. What will be the value of response modification factor (R)?
a) 6
b) 7
c) 8
d) 9
Answer: c
Clarification: Since it is made up of reinforced concrete beam, r will be approximately 8.

3. What will be the total static lateral base shear?
a) 66g
b) 450g
c) 327.27g
d) 427.27g
Answer: c
Clarification: Calculate v using the formula V = S_DSW/(TR/I) which comes out to be 327.27g and also find V_max and V_min which comes out to be 66g and 450g. Thus V_max > V > V_min and the answer is c.

4. What will be the value of distribution coefficient k in the above question?
a) 1.4375
b) 1.4875
c) 1.3375
d) 1.3875
Answer: a
Clarification: K = 1+((T-.5)/2), and vale of T as calculated above is 1.375.

5. Find the lateral seismic load applied at 4^th level.
a) 41.378
b) 65.59
c) 65.378
d) 66.378
Answer: b
Clarification: F_x= (W_x h_x^k V)/(Σw_i h_i^k). Here, x = 4 and the value of denominator term is 2714.735. Also, V has already been calculated in above questions.

6. What will be the summation of the entire individual floor lateral seismic load?
a) 4V
b) 3V
c) 2V
d) V
Answer: d
Clarification: On summing all the term of the equation used in the above question, e will see that they cancel out each other and only the term v remains. Also, analytically sum of forces on each level should be equal to the net seismic force/load.

7. Exposure index (C_c) is intended to account for the snow that can’t be blown from the roof because of the surrounding locality.
State whether the above statement is true or false.
a) True
b) False
Answer: b
Clarification: Exposure index (C_c) is intended to account for the snow that can be blown from the roof because of the surrounding locality.

8. If city A has clay foundation and city B has rock bed foundation, then what will be the relation between design spectral accelerations (S) of both cities?
a) SA < SB
b) SA > SB
c) SA = SB
d) Depends upon type of earthquake
Answer: b
Clarification: Clay is weaker foundation material. So, S_D1 and S_DS will be larger for it than rocky base.

9. Which of the following material will have the highest value of response modification factor?
a) Reinforced concrete shear walls
b) Wood
c) Reinforced concrete frames with flexible joints
d) Structural steel frames
Answer: d
Clarification: More ductile a material is, higher will be the value of response modification factor.

Structural Analysis for Freshers,