Tunnels or galleries specially adapted to house conduits

Official title: {Tunnels or galleries specially adapted to house conduits, e.g. oil pipe-lines, sewer pipes (for pressure water conduits E02B9/06; for cables H02G9/02; layout of tunnels or galleries in general E21D9/14; road kerbs with housings for pipes or the like E01C11/222); Making conduits in situ, e.g. of concrete (combined with digging of trenches or ditches E02F5/10; making or lining tunnels or galleries E21D; constructing tunnels or galleries in open excavations E02D29/045; in open water E02D29/063); Casings, i.e. manhole shafts, access or inspection chambers or coverings of boreholes or narrow wells (wells for drinking water E03B3/08; boreholes or wells formed by deep drilling E21B; shafts E21D)}

E02D29/10 (Tunnels or galleries specially adapted to house conduits) appears on 36 US grants and 48 published applications in this corpus.