§ Mr. David MarshallTo ask the Secretary of State for Transport what studies his Department has made into the possibility of using channel tunnel construction methods to build roads in urban areas; and if he will make a statement. [30958]
677W
§ Mr. WattsThis is an operational matter for the Highways Agency. I have asked the chief executive to write to the hon. Member.
Letter from Lawrie Haynes to Mr. David Marshall, dated 28 June 1995:
Mr. John Watts has asked me to reply to your recent Parliamentary Question about the possibility of using Channel Tunnel construction methods for building roads in urban areas.The notable success of the civil engineering construction on the UK side of the Channel Tunnel project included the performance of the full-face boring machines that were used to excavate and line the main running tunnels and the service tunnel that link the UK with mainland Europe, the construction of a huge underground cross-over chamber by means of excavation and ground support techniques known as the New Austrian Tunnelling Method (NATM) and extensive cut and cover construction at the terminals. The full-face boring machine techniques and cut and cover construction are well established and already used to construct urban roads where appropriate.NATM is a relatively new, very flexible and economic form of tunnelling that promises to be of particular benefit in the construction of the comparatively short lengths of tunnel required in most urban developments (i.e. less than 1 km long). The technique has been a topic of research and development commissioned by the Agency. NATM has already been adopted for two recently constructed twin trunk road tunnels (A20 Round Hill 390 m and A27 Southwick 490 m) both of which were constructed in chalk. Experience gained from studies carried out at both of these projects has shown that NATM could be well suited to the demands of underground construction in urban areas. Work is continuing to justify this assumption.