How to formulate the railway alignment and decide between above-ground and underground scheme options?
When planning the railway alignment, we will carefully study details of the surrounding areas, such as the environment, topography, geology, population distribution, etc. We will also analyse the cost and benefits, constructability, potential impacts on nearby ecology and communities, land development requirements, implications on future railway extensions, operation and maintenance, etc., of different alignment options.
As for the above-ground or underground scheme options, both have their relative pros and cons, for example:
|
Scheme option / Factors in determining the scheme |
Above-ground |
Underground |
|
Engineering considerations on understanding of geological conditions |
Vary in different situations |
|
|
Engineering considerations on construction techniques |
Vary in different situations |
|
|
Predictability of construction time |
Relatively higher |
Relatively lower |
|
Impact on use and development of above-ground lands |
Relatively more |
Relatively less |
|
Impact on environment, including surrounding ecology, especially for ecologically important sites |
Relatively long-term |
Relatively short-term |
When formulating railway alignment, we will conduct studies on underground and above-ground scheme options and listen to the views from different stakeholders. After preliminary assessment and consideration of various factors, the underground scheme is considered as a sustainable option for the Northern Link and could actively respond to the opinions of stakeholders. We are now conducting further technical studies and design works based on the underground scheme option. The actual alignment and station locations of the Northern Link will be announced later.
