4: Seismic Risk Mitigation

Question 1

Land use planning is based on ____ ____ maps

Answer 1

hazard micro-zonation

Question 2

What are the four main factors that should be accounted for in land use planning?

Answer 2

(1) probability of EQ intensity (2) peak ground accelerations (3) areas prone to secondary EQ effects such as liquefaction, flooding (4) building vulnerability: fire potential, distance from communication lines

Question 3

What is Eurocode 8, and when was it introduced?

Answer 3

A regulatory code for new infrastructure, 1998

Question 4

What is the main problem with building codes worldwide?

Answer 4

Not always enforced

Question 5

Anti-seismic design principles require understanding of ____ and _____

Answer 5

How the ground shakes during an earthquake, how built structures respond

Question 6

Name the five main ways that damage to buildings during earthquakes can be reduced.

Answer 6

(1) Strengthening structures (2) Isolating bases of buildings from ground (3) Using dampers to reduce vibrations (4) Installing dynamic control systems (5) Securing building contents and services

Question 7

If the ground shakes at the buildings ____, the building shakes more strongly, which is known as ____

Answer 7

Fundamental frequency, resonance

Question 8

What is the general range of frequency that a ground shakes at during an EQ?

Answer 8

0.1 – 10 hz

Question 9

Taller buildings tend to have ___ fundamental frequency due to increased ___ and reduced ___

Answer 9

lower, mass, stiffness

Question 10

The general rule is that a buildings frequency is about ___ Hz divided by ___

Answer 10

10 hz, number of floors

Question 11

____, ____ structures with a height : width of ____ tend to preform best in EQ’s

Answer 11

symmetrical, continuous, <4

Question 12

When it comes to extending a building, avoiding ____ is useful for EQ mitigation. The building will stand to be more earthquake proof if all structural elements of the building are ____

Answer 12

differential materials, securely connected together

Question 13

What three ways can we test structural integrity of a building to mitigate EQ hazard?

Answer 13

Shake tables, computational models, real EQ observations

Question 14

Ideally building materials should be a combination of high ___, high ____ and low ____ for earthquake hazard mitigation

Answer 14

High strength, high ductility, low weight

Question 15

What is the best material to use as a strengthening material for earthquake hazard mitigation?

Answer 15

Timber

Question 16

What are the three possible disadvantages of using timber for earthquake hazard mitigation

Answer 16

Unavailable, vulnerable to fire, vulnerable to rotting

Question 17

___ is the next best property to use after timber, due to its ___ and ___ properties.

Answer 17

Steel, strong, ductile

Question 18

Reinforced concrete has a ____ strength to weight ratio compared to timber and steel.

Answer 18

Poor

Question 19

The worst strengthening material used in buildings is ____, as it is ___ and ___.

Answer 19

Unreinforced concrete, brittle and heavy

Question 20

____ a building is usually cheaper than ____ a building when it comes to seismic hazard mitigation, but it is still costly and requires ____

Answer 20

Strengthening, rebuilding, careful planning

Question 21

In poor rural areas it is best to concentrate on what three ways of building improvements?

Answer 21

Removing defects, low-cost strengthening, education for builders

Question 22

What are the three main high-tech earthquake-engineering approaches?

Answer 22

Base isolation, damping, dynamic control systems

Question 23

Base isolation places ___ between the ___ and the ____, made from layers of ____ and ___. The design allows high ___ strength but low ___ strength, allowing for ___ motion during an earthquake

Answer 23

Bearings, foundation and ground floor, rubber and steel, vertical, horizontal, horizontal

Question 24

What are the three types of earthquake damping systems?

Answer 24

Viscous damper, friction damper, yielding damper

Question 25

What does a seismic damping system do?

Answer 25

Absorbs seismic energy

Question 26

What would the three types of seismic damping systems look like when implemented into a building?

Answer 26

See Picture

Question 27

Give an example of a dynamic control system as a type of earthquake hazard mitigation currently in place today

Answer 27

Taipei 101 building in Taiwan, a pendulum which moves against the mass movement of the building due to EQ or wind hazards.

Question 28

What is a dynamic control system as a type of earthquake hazard mitigation?

Answer 28

An intelligent system which adjusts to correspond with shaking or movement of a building

Question 29

Name a way that a household could monetarily cover themselves for earthquake damage

Answer 29

Earthquake Insurance

Question 30

What technological characteristic makes EQ early warning systems possible?

Answer 30

EM waves travel faster than S waves

Question 31

What is the single station approach in an earthquake early warning system?

Answer 31

Station detects P-wave and issues the alarm on site

Question 32

What is the network approach for an earthquake early warning system?

Answer 32

Station detects P-wave, issues the alarm onsite and instantly passes on to neighboring stations, who issue their own alarm. Combines information from everywhere.

Question 33

What is one advantage and one disadvantage for the single station approach for an earthquake early warning system?

Answer 33

Advantage: rapid, Disadvantage: significant uncertainty

Question 34

What is one disadvantage and two advantages for the network approach for an earthquake early warning system?

Answer 34

Advantages: better warning at greater distances, more accurate. Disadvantage: slower for epicentral region

Question 35

What is the main limitation for an earthquake early warning system?

Answer 35

Only gives seconds of warning – not enough time for evacuation

Question 36

What is needed for an accurate and effective networked early warning system?

Answer 36

Density and scope of the systems across potential hazard region

Question 37

What is the USGS’s automated earthquake response system?

Answer 37

PAGER