Pre Event Managament Flashcards
What are the main pre-event management strategies for mass movement?
Building design, tsunami defences, slope stabilization, GPS crater monitoring, lava diversions
These strategies aim to mitigate the impact of geophysical hazards.
What is slope stabilization?
A method to prevent mass movement by addressing the specific geological conditions of the slope
It can include techniques like piling, drainage systems, and other engineering solutions.
What is the lowest-cost solution for the Guinsaungnon landslides?
Relocation of the town
This was feasible due to the small population of 1,500.
Why is slope failure influenced by pore-water pressure?
It can cause sediments to become more vulnerable to movement
Tectonic fracturing may also contribute to slope failure.
What are some small-scale slope stabilization techniques?
- Mesh Curtains
- Bench Steps
- Gabion Boxes
- Soil Nails
- Slope Grillage
These techniques offer localized solutions to prevent rockfalls and stabilize slopes.
What are the two main focuses of earthquake engineering?
- Mitigating risks induced by earthquakes
- Designing structures to withstand earthquakes
Civil authorities typically focus on risk mitigation, while structural designers concentrate on building safety.
What does ductility refer to in the context of seismic design?
The capacity of a mechanical system to deform without significantly reducing its bearing capacity
Ductility is important for ensuring structural safety during earthquakes.
True or False: Tall buildings are generally considered more at risk from seismic stress than small buildings.
False
Tall buildings can sway naturally and behave in a ductile manner, unlike smaller, more brittle structures.
What is a ‘life safe’ home in the context of seismic design?
A home designed to be safe during seismic events, adhering to specific building regulations
The ‘How Safe is My House Project’ in the Philippines provides guidelines for such designs.
What are tsunami walls and their purpose?
Hard engineering solutions to protect coastline settlements from tsunami waves
They are often constructed from reinforced concrete and can be vertical or sloping.
What are some potential limitations of tsunami walls?
- Limited protection from the sea
- Can be overtopped by large waves
- May create a false sense of security
The effectiveness of tsunami walls depends on their height and construction quality.
What is the significance of monitoring for volcanic activity?
It provides warning signs that increase in frequency leading up to an eruption
Monitoring includes measuring changes in shape, gas concentrations, and seismic activity.
What was one of the earliest attempts to control lava flow?
A breach was opened in the flank of a lava flow in Sicily in 1669
This attempt successfully redirected the flow but destroyed a neighboring village.
Fill in the blank: ‘Earthquakes don’t kill people, ________ do.’
collapsing buildings
This highlights the importance of building design in earthquake safety.
What is a significant challenge in relocating populations affected by landslides?
Large population sizes, as seen in Mocoa with 55,000 residents
Relocation is often the preferred option but logistically challenging.
What are gabion boxes used for in slope stabilization?
To provide stability by offering shear strength to the base of the slope
They consist of wire mesh boxes filled with loose rocks.
What is the role of base isolation in seismic design?
To reduce the movement of the main structure during an earthquake
It is considered an effective method for protecting buildings.
What was the cost of building 400 kilometers of new tsunami walls in Japan?
$11 billion
This project is known as the ‘Great Wall of Japan’ and reflects the high costs of tsunami protection.
