COMBINATION TUBBING FOR TUNNEL LINING AND METHOD OF ITS PRODUCTION Russian patent published in 1998 - IPC

FIELD: tunneling technology. SUBSTANCE: this relates to building of underground structures in watered ground and it is aimed at increasing load-bearing capacity and waterproofness of tunnel lining. Ribs at places of installing bolts are made double-layer, they are steel perforated strips welded with cast iron covering. Laid over entire perimeter of tubbing is steel wire. According to method of producing combination tubbing, assembly of central slag-stone core is carried out on stand by building it from separate shells with formation of functional joints due to application of wedges and filling joints with low-modulus thermally active material. Shells are connected to each other by welding steel rods to embedded parts of shells. Mounted in corners of shells are steel perforated strips and mould bars or used are steel boxes filled with moulding sand for creation of recesses in tubbing body at places of installing bolts. Steel strips or boxes with slag and cast stone shells are connected by means of wire. Assembled tubbing core is installed in lower half of casting mould, steel rods are cut off, wedges are removed from functional joints, upper half of casting mould is installed with ensuring required clearance, clearance is filled with molten cast iron at temperature of 1200-1400 C. EFFECT: higher efficiency. 2 cl, 6 dwg