Part 6/7:
Upstream Method:
Advantages: Uses less material and is cheaper.
Disadvantages: More sensitive to liquefaction and instability, not suitable in seismic regions like Chile.
Downstream Method:
Advantages: Provides more stability, hence safer.
Disadvantages: Requires a greater quantity of materials, leading to higher costs.
Center Line Method:
Advantages: Balances material usage and stability, making it a middle-ground option.
Disadvantages: While it is more stable than Upstream, it may still be less stable than Downstream.