TRANSPORTATION TUNNELS UNDER HIGHWAYS

The requirements which must be met in constructing tunnels under highways are stated, comments are made on the excavation and construction of such tunnels, and reference is made to the Kansas City underground environment. The first step in the construction is the development of a comprehensive plan and its presentation for approval to the various Federal, State and local agencies involved. The construction and mining procedure must cover all possible conditions to be encountered. The plan must be based on exploration of the ground conditions by visual observation, exploratory drilling, and information related to the conditions of the original highway construction. Spilling, breast boarding, shotcrete or liner plate may be required by the presence of compacted fill. Ground conditions which necessitate top heading and bench method of tunnel excavation are also discussed. The pros and cons are presented of using tunnels in Kansas City for highways.