# T/F An x- braced frame typically has stiffness/stability provided by connections rather than geometry

LAWRENCE TECHNOLOGICAL UNIVERSITY

College of Architecture and Design

ARC5543/ARC4543 Advance Structures TEST No. 2 July 10, 2021

Instructor: Faris R. Habba

_____ .

Name: I.D.:

I agree not to discuss the contents of this exam until it is returned to me. I have neither given nor received any

unauthorized aid in completion of this exam. __________________________ (your signature required)

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Q1. (15 @ 2 pts = 30 pts)

1. T/F An x- braced frame typically has stiffness/stability provided by connections rather than

geometry.

2. T/F The transmission of lateral loads is related to the stiffness properties of the frame.

3. T/F A diaphragm chord on the leeward side of a structure is evaluated in compression.

4. A flexible diaphragm would transfer loading to shear walls in a equal or unequal manner.

(Circle correct response)

5. T/F Portal frames are suitable for industrial or agriculture storage buildings.

6. The Portal Method of Analysis assumes the column shear values at end columns is (larger or

smaller) than the interior columns. (Circle correct response).

7. T/F A base isolation system would be able to absorb some seismic energy but the demands on

the frame is that it is rigid.

8. T/F Shear walls should align vertically in a building structure when considering seismic

forces.

9. Indicate the appropriate evaluation method for the two frames shown in section. (see drawing

at right).

10. Which of the four options A, B, C, D would best resist seismic and winds loads?

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11. The frame shown below is subjected to a concentrated lateral load. Which of the following is

the correct bending moment diagram?

12. The frame shown below is subjected to a uniformly distribt1ted gravity load. Which of the

following is the correct shear force diagram for the frame shown below?

13. Which of the following statements regarding a concrete floor diaphragm is correct?

a. It acts as a simple beam between the vertical lateral force resisting system

b. It distributes 1ateral forces in proportion to the relative stiffness of the elements of the vertical

lateral force resisting systems

c. It acts as a flexible diaphragm.

d. It distributes the lateral forces in proportion to the tributary width of the vertical lateral force

resisting systems

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14. If a building is designed for a non-seismic location, which of the following effects are not

considered.?

I. Liqt1efaction

II. Tsunamis

III. Overturning

IV. Uplift

a. I and III

b. I and II

c. I, II, and III

d. I, II, Ill, and IV

15. Which of the following building elevations has the best performance in a seismic zone?

Q2. (10 @ 3 pts = 30 pts)

Show Calculations. Failure to show calculations will result in a grade of zero.

1. The following shear wall is made of 12″ concrete with a unit weight of 150 lb/ft3. It is

subjected to the applied loads shown. What is the safety factor of this wall again overturning?

a. 0.68

b. 1.46

c. 1.68

d. 0.4

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2. What is the maximum chord force for the roof diaphragm of the figure below?

3. What is the horizontal reaction for the exterior supports of the moment frame shown below?

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4. What is the shear force to be resisted by the interior concrete wall (B) assuming that it is three

times as rigid as the exterior walls (A) and the diaphragm is flexible?

5. What is the shear force in the left concrete shear wall (A) assuming that it is twice as rigid as

the one on the right (B), and the diaphragm is rigid?

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6. Evaluate the stability of the frames shown.

7. Evaluate the stability of the frames shown.

8. Sketch the general shape the moment diagrams for the frame shown, no calculations needed.

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9. What are the vertical reactions on the ground for the frame shown?

What is the horizontal reaction at the pin on the upper right?

_____________ kips

10. Sketch the general shape the moment diagrams for the frame shown, no calculations needed.

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Q3.

Show Calculations. Failure to show calculations will result in a grade of zero.

A. Find the support reaction

(2 pts) Ax =

(2 pts) Ay =

(2 pts) By =

B. Find the brace force

(2 pts) F1 =

(2 pts) F2 =

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Q4. (10 pts.)

Determine the base shear for the proposed six-story office building shown in Figure below. The

structure of the building consists of steel moment-resisting frames (all joints are rigid) that have

an R value of 8. The 75-ft-tall building is located in a high seismic region with SD1 = 0.4g and

SDS = 1.0g for a building supported on rock, where g is the gravitational acceleration. TL = 8 sec

per (ASCE 7 Figure 22-12), and given the deadweight of each floor is 700 kips. The occupancy

importance factor I is 1 for office buildings.

Show Calculations. Failure to show calculations will result in a grade of zero.

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Q5. (10 pts.)

Show Calculations. Failure to show calculations will result in a grade of zero.

Calculate the vertical distribution of base shear for the proposed 3 – story apartment building as

shown in Figure below. Each floor is 10′ tall and consider typical floor load to be 125 kips and

roof load to be 91 kips.

Given: Base shear = 47.22 kips, and the fundamental period Ta(s) of the building =0.384s.

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Q6. (10 pts.)

Show Calculations. Failure to show calculations will result in a grade of zero.

Determine the diaphragm design forces for the two-story health care facility shown below. given

the design data below.

The base shear loads per floor are given, as shown in Figure below (Fx2 = 3.5 kips, and Fx1 =

1.87 kips)

Base shear = 5.37 kips, the fundamental period Ta(s) of the building =0.56 s, SDS = 0.302 s, and

Ie = 1.25

Typical floor Total Seismic Load = 28 kips /floor

Roof total seismic load = 18 kips

Each floor is 12′ tall 