Structural

INFLUENTIAL FIGURES

Marc Brunel – THE FIRST TUNNEL

James Greathead – THE FIRST DEEP-LEVEL TUNNEL

LONDON
The earth under London is composed of a bed of clay, therefore making tunneling much easier. It is one of the most tunneled cities in the world, with tunnels for road vehicles, pedestrians, the Tube and railway lines and utilities. Several tunnels are over a century old.

THE NETWORK
There is 150km of tube tunnel of which 32km is cut and cover tunnel. The other 55% of the system runs on the surface.

SUB SURFACE NETWORK
The Circle, District, Hammersmith & City, and Metropolitan lines are services that are on the sub-surface network. The railway tunnels are just below the surface and built mostly using the “cut and cover” method. The trains are similar in size to those on the British main above ground lines.

DEEP-LEVEL TUBE LINES
The Bakerloo, Central, Jubilee, Northern, Piccadilly, Victoria and Waterloo & City lines are deep-level tubes; they have smaller trains that run in two circular tunnels. Many of the central stations on the deep-tube lines are higher than the running lines to assist deceleration when arriving and acceleration when departing (Central and Piccadilly lines). The deep tunnels have a diameter of about 3.59m and are lined with cast-iron or precast concrete rungs. They are bored using a tunneling shield.

Tunneling Under the River Thames

METHODS OF CONSTRUCTION

1. Cut and Cover Method

2. Tunneling Shield: Greathead Method

Constructing the Metropolitan Railway

Constructing the Metropolitan Railway

Cross-section of Piccadilly Circus

Cross-section of Piccadilly Circus

Cross-section of Covent Garden

Cross-section of Covent Garden

Cross-section of Monument and Bank Stations

Cross-section of Monument and Bank Stations

Section of the New Charing Cross

Section of the New Charing Cross

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s