GB511373A - Improvements relating to the construction of underground chambers - Google Patents

Abstract

511,373. Constructing underground chambers. HUNTER, C. M. March 11, 1938, No. 7685. [Class 68 (i)] Underground chambers for storage, garaging vehicles or for use as air raid shelters, are formed by arranging at least two rows of spaced piles in the ground prior to commencement of the excavation, the outer row being arranged along the line of the side wall of the chamber, progressively excavating between the piles, and constructing a retaining wall round the side of the chamber, said wall being connected to the outer piles which are themselves connected to inner piles. In Fig. 3, piles 1 are placed around and over the area of the site and a spoil shaft 2 is formed; excavation then proceeds from the spoil shaft in layers 6-12, which may be independent, or from one or more continuous spirals, and roofs 13 and floors 14 are formed and integrally connected with the piles, wallretaining members 15 being built in between piles of the outer row. Lifts, ramps &c. may give access. In Figs. 7 and 10 three circular rows of piles 17 are placed and excavation is effected in layers, which may correspond to the floor heights, from the surface, and the piles are progressively braced together and to wallretaining members 21 by braces 22. A foundation 23 is then formed, on which is built a structure comprising floors 26 carried by the two outer rows of piles and by strong, widely-spaced pillars 27. The innermost row of piles is then removed and a roof 25 and bomb-proof cover 28 is formed. This form may be modified by placing piles suitably spaced over the whole area, the piles being left in place to form a permanent part of the structure. Additional piles may be placed around the site to reinforce the ground, and may be tied to the chamber. The piles may be formed by boring holes larger in diameter than the piles and extending to or below the bottom of the chamber, a sectional tubular casing being then lowered into each hole and filled with cement to which pressure is applied to force the cement up around the casing; alternatively pre-formed piles may be driven, or lowered into holes, or structural steel or iron columns may be used and may be built up of profile bars connected by plates. The wallretaining members 15, 21 may be of concave steel or iron sheets, or reinforced concrete, behind which concrete may be inserted, and the piles may have grooves to receive such members.