Module 2: Structural Framing Systems and Irregularities

Question 1

8 Structural Framing Systems

Answer 1

1. Bearing Wall Systems
2. Moment-Resisting Frames Systems
3. Building Frame System with Shear Wall
4. Building Frame System with Braced Frames
5. Dual System
6. Shear Wall Frame Interactive System
7. Cantilever Column System
8. Steel Systems not specifically detailed for Seismic Resistance

Question 2

4 Types of Bracing Systems

Answer 2

1. Special Steel Concentrically Braced Frames
2. Ordinary Steel Concentrically Braced Frames
3. Buckling-Restrained Braced Frames
4. Steel Eccentrically Braced Frames

Question 3

Structural Irregularities (Horizontal Irregularities)

Answer 3

1. Torsional
2. Re-entrant
3. Diaphragm Discontinuity
4. Out-of-plane Offset
5. Non Parallel System

Question 4

is used to transfer the lateral forces acting on the structure to the foundation

Answer 4

Lateral force-resisting system

Question 5

are used to provide continuous load path

Answer 5

Vertical and Horizontal Components

Question 6

It consists of frames, shear walls, or a combination of both

Answer 6

Structural Framing System

Question 7

This resists all lateral forces and supports most of the gravity loads

Answer 7

Shear Wall

Question 8

Structural framing system that has no shear wall

Answer 8

Moment-Resisting Frame System

Question 9

2 Properties of Framing

Answer 9

Center of Mass
Center of Rigidity

Question 10

measures a structure’s ability to withstand seismic forces.

Answer 10

Response modification coefficient (R)

Question 11

Torsional deflections happen when ———

Answer 11

eccentricity exists

Question 12

It is the twisting point of a floor level and what causes torsion on the building

Answer 12

Center of Rigidity

Question 13

It is the strength of columns below story level

Answer 13

Story’s lateral strength

Question 14

it is the maximum story drift at the building’s edge

Answer 14

∆max

Question 15

it is the average of the story drift at the two opposing edges of the building

Answer 15

∆avg

Question 16

Torsional Irregularity exists when TIR is (greater than or less than?) ____

Answer 16

greater than 1.2

Question 17

it is the total strength of all seismic-resisting elements sharing the story shear for the direction under consideration

Answer 17

story lateral strength

Question 18

Formula of TIR

Answer 18

∆max/∆avg > 1.2

Question 19

Re-entrant corner Irregularity exists when the cutout is greater than ____ of the plan dimension of the structure in the given direction

Answer 19

20%

Question 20

Diaphragm Discontinuity Irregularity exists when the cutout or open area is greater than ______ of the gross enclosed diaphragm area

Answer 20

25%

Question 21

Diaphragm Discontinuity Irregularity also exists when the change in effective diaphragm stiffness of more than ____ from one story to the next

Answer 21

50%

Question 22

This irregularity exists when there is a discontinuity in a lateral force-resistance path

Answer 22

Out of Plane Offset Irregularity

Question 23

This irregularity exists when vertical lateral force-resisting elements are not parallel to the major orthogonal axes of the seismic force-resisting system

Answer 23

Non-Parallel System Irregularity

Question 24

Structural Irregularities (Vertical Irregularities)

Answer 24

1. Stiffness-Soft Story Irregularity
2. Stiffness-Extreme Soft Story
3. Vertical Geometric Irregularity
4. In-Plane Discontinuity in Vertical Lateral Force-Resisting Element
5. Discontinuity in Lateral Strength - Weak Story
6. Discontinuity in Lateral Strength - Extreme Weak Story

Question 25

This irregularity exists when the lateral stiffness is less than 70% of that in the story above.

Answer 25

Stiffness - Soft Story Irregularity

Question 26

This irregularity exists when the effective mass (weight) of any story is more than 150% of the effective mass of an adjacent story.

Answer 26

Discontinuity in Lateral Strength - Extreme Weak Story