Design Philosophies

Question 1

A condition in which structure becomes unsafe due to possible collapse of the structure.

Answer 1

Strength Limit State

Question 2

Excessive vibration is an example of strength limit state

Answer 2

False

Question 3

Resistance to flexure is an example of serviceability limit state

Answer 3

False

Question 4

Working stress design and ultimate strength design are considered limit state design

Answer 4

False

Question 5

ASD and LRFD are generally the same in terms of providing adequate factor of safety

Answer 5

False

Question 6

Allowable stress must always be greater than or equal to actual stress is a strength design approach

Answer 6

True

Question 7

Overloading of structures and under strengthening of members are the factors of safety _______ design method

Answer 7

Load and resistance

Question 8

The usual factor of safety given to beams and tension members is ______

Answer 8

1.67

Question 9

Connection design have bigger factor of safety than member design like columns and beams because connection failure are

Answer 9

Brittle

Question 10

The load factor used in strength design method depends on

Answer 10

type of member

Question 11

since LRFD or strength design method involved several factors of safety, the probability of failure is given by the margin of safety as well as

Answer 11

Reliability Index

Question 12

Importance of the member of the structure may affect the reduction factor value

Answer 12

True

Question 13

LRFD or strength design method will always be safer ans economical than ASD and WSD

Answer 13

True

Question 14

The potential limit state are the same for every structural member subjected to a specific load requirement

Answer 14

False

Question 15

Plastic design is and limit state design is a part of a limit state design

Answer 15

True

Question 16

The allowable strength design method is a patterned after

Answer 16

WSD

Question 17

The safety criterion in design allows that

Answer 17

R>0

Question 18

The factor of safety in design is given by

Answer 18

R/Q

Question 19

In the allowable stress design method, the factor of safety is given to the resistance and no factor of safety is given to the actual ________

Answer 19

nominal strength

Question 20

when the factor of safety is high, the reliability index is

Answer 20

high

Question 21

the factor of safety for connection ranges from 2.5 to 3 because it is

Answer 21

critical

Question 22

LRFD is based on

Answer 22

probability

Question 23

the coefficient of the load factors for ASD are

Answer 23

based on judgment

Question 24

factor of safety are provided in LRFD both on factored load and

Answer 24

understrength

Question 25

reduction of live loads L are made because it is unlikely that the area of load applictation will not cover

Answer 25

less than 50%

Question 26

LRFD is about

Answer 26

capacity determination

Question 27

in design survival means

Answer 27

R>Q

Question 28

In (R/Q)<0= Failure is the same as

Answer 28

both

Question 29

when a design is conservative it follows that it is

Answer 29

expensive

Question 30

dead loads differ with live loads depending on how long the load is applied on the member

Answer 30

True

Question 31

Lr stands for

Answer 31

roof live load

Question 32

what is the factor of safety for a dead load of 10kn and an understrength factor of 0.85 if the overload factor of 1.2 is applied dead load (Use LRFD)

Answer 32

1.41

Question 33

determine the value of L if a live load of 100kn is place over a garage area of 20 sqm

Answer 33

5 kpa

Question 34

why are earthquake and wind not combined for a possible design load combination

Answer 34

they don’t usually exist together

Question 35

a conservative design is

Answer 35

very safe but expensive

Question 36

an efficient design is

Answer 36

strong and economical