新概念2 第64课 (课堂PPT)

Background information
英吉利海峡隧道（The Channel Tunnel)又称英法海底 隧道或欧洲隧道（Eurotunnel)，是一条把英国英伦三 岛连接往欧洲法国的铁路隧道，于1994年5月6日开通 。它由三条长51km的平行隧洞组成，总长度153km，其
✓ Travelling through a tunnel is significantly quicker and won't be influence during adverse weather
Profileቤተ መጻሕፍቲ ባይዱof The Channel Tunnel :
>> The Channel Tunnel also referred to as the Chunnel is a 50.5kilometre undersea rail tunnel linking Folkestone in the United Kingdom with Calais in northern France beneath the English Channel at the Strait of Dover.
rail tunnels is a piston relief duct, necessary to manage pressure
changes due to the movement of trains
Construction ：
• Precast segmental linings in the main TBM drives were used, but different solutions were used on the English and French sides.
>> At its lowest point, it is 75 meters deep. At 37.9 kilometers , the
Channel Tunnel possesses the longest undersea portion of any tunnel in
the world, although the Seikan Tunnel in Japan is both longer overall at
53.85 kilometers , and deeper at 240 meters below sea level.
The Channel Tunnel
The Seikan Tunnel
• Ideas for a cross-Channel fixed link appeared as early as 1802
• began construction in 1988 and opened in 1994
• eventually closed in 2002 for incident
Engineering：
• The British Channel Tunnel Group consisted of two banks and five construction companies, while their French counterparts.
>>On the French side, neoprene and grout sealed bolted linings made of cast iron or high-strength reinforced concrete were used.
>>On the English side, the main requirement was for speed and bolting of cast-iron lining segments was only carried out in areas of poor geology.
• An undersea tunnel is a tunnel which is partly or wholly constructed under a body of water.
Advantages:
✓ Tunneling will generate soil that has been excavated[ˈekskəˌveɪtid] and this can be used to create new land, as was done with the soil of the Channel Tunnel.
stratum .
>>Successful tunnelling under the channel required the selection of the best rock strata .
Typical tunnel cross section:
with a service tunnel between twin rail tunnels. Shown linking the
• The French Channel Tunnel Group consisted of three banks and five construction companies.
• The design and construction was done by the ten construction companies.
New Concept English（Book 2 ） (新概念英语)（第二册）
新概念二 Lesson 64
The Channel Tunnel 海峡隧道
The Channel Tunnel
----The world's longest undersea tunnel
What is Undersea tunnel?
Geological profile along the tunnel as constructed:
>>The geology generally consists of northeasterly dipping Cretaceous strata .
>>For the majority of its length the tunnel bores through a chalk marl