GEOLOGICAL RESULTS OF THE CHANNEL TUNNEL SITE INVESTIGATIONS 1964-65

Abstract

THE STRUCTURE AND STRATIGRAPHY OF THE STUDY AREA, BASED ON THE GEOPHYSICAL INVESTIGATIONS AND BOREHOLES CARRIED OUT, ARE DESCRIBED, WITH PARTICULAR REGARD TO THE LOWER CHALK (CENOMANIAN). THE RESULTS OF AN EXTENSIVE PROGRAM OF LABORATORY TESTING ON CORES, AND TESTS IN BOREHOLES TO DEDUCE THE GROUND PERMEABILITY, ARE SUMMARIZED, AND THEIR RELEVANCE TO THE CHOICE OF ROUTE FOR A 'BORED' TUNNEL IS DISCUSSED. BOTTOM SAMPLING, CURRENT AND TIDAL STUDIES PERFORMED TO INVESTIGATE THE FEASIBILITY OF AN 'IMMERSED TUBE' ARE ALSO DESCRIBED. IT IS CONCLUDED THAT BOTH TYPES OF TUNNEL ARE GEOLOGICALLY FEASIBLE. /AUTHOR/