2nd EQ Quiz

Question 1

Multi-storey buildings are the most suitable example. These may be divided into two groups:

Answer 1

-Shear Buildings
-Moment Shear Buildings

Question 2

The floors move only in the horizontal direction and there is no rotation of a horizontal section at the level of the floors.

Answer 2

Shear Buildings

Question 3

The floors move in both the rotational and horizontal directions.

Answer 3

Moment-Shear Buildings

Question 4

is the force required to produce a unit displacement
of the two adjacent floor levels.

Answer 4

stiffness coefficient or spring constant, kj

Question 5

involve the estimation of dynamic soil properties and the study of the behaviour of various types of soils under dynamic loads.

Answer 5

SOIL DYNAMICS

Question 6

The ________ of earthquakes is the most critical.

Answer 6

wave action

Question 7

The extent of damage caused by earthquakes depends essentially on the dynamic response of soil deposits, which is governed by the cyclic nonlinear and strength characteristics of soil. Ground response analysis is used for the following:

Answer 7

1. To predict ground surface motion for the development of design response spectra.
2. To evaluate dynamic stresses and strains for the evaluation of liquefaction hazards.
3. To determine the earthquake-induced forces.

Question 8

Soil dynamics problems are generally divided into either:

Answer 8

-small strain amplitude responses
-large strain amplitude responses

Question 9

to solve many important problems, particularly those dominated by wave propagation effects, only strains of small amplitude are induced in the soil.

Answer 9

small strain amplitude responses

Question 10

for other problems such as those involving the stability of masses of soil, large-
amplitude strains are induced.

Answer 10

large strain amplitude responses

Question 11

Under the influence of earthquake loading, the soil element may be one of the following
conditions:

Answer 11

1. The initial static stress is large and the additional stresses induced by the
   earthquake are small (Figure a). Here, a symmetrical pulsating stress system is
   superimposed on an initial sustained stress.
2. The sustained stress is small and the pulsating strain is larger. The combined
   effect is shown in Figure b.

Question 12

Soil behavior under dynamic loading depends on the strain magnitude, the strain rate,
and the number of loading cycles. The strength of certain soils increases under rapid cyclic
loading, while saturated sand or sensitive clay may lose strength with vibration.

Answer 12

Dynamic Behavior of Soil

Question 13

Loose sands can get compacted under _________.

Answer 13

vibration

Question 14

A simple method to predict settlement consists of determining the ____________

Answer 14

critical void ratio,

Question 15

maximum amount of possible settlement can be determined by

Answer 15

∆H = ((ecr − e)/(1 − e))*H

Question 16

H is the ______________

Answer 16

depth of the stratum.

Question 17

critical void ratio is given by

Answer 17

ecr = emin + (emax − emin) e^(−0.75a/g)

Question 18

under earthquake loading, some soils may compact, increasing the pore
water pressure and causing a loss in shear strength, and behave like liquid mud.

Answer 18

Liquefaction

Question 19

_________ is not susceptible to liquefaction.

Answer 19

Gravel or clay

Question 20

__________ are less likely to liquefy than
___________

Answer 20

Dense sands

loose sands,

Question 21

______________ are particularly vulnerable due to their
uniformity.

Answer 21

hydraulically deposited sands

Question 22

If liquefaction is likely to be a hazard, the use of _______________________
necessary in order to avoid unacceptable settlement or foundation failure during an
earthquake.

Answer 22

deep foundation or piling may be

Question 23

The strength of sand is entirely due to __________.

Answer 23

internal friction

Question 24

The strength of sand is entirely due to internal friction. In a saturated state, the strength
may be expressed as

S = σn − u tan ∅

Answer 24

Theory of Liquefaction