GB325093A - Improvements relating to the provision of substructures, particularly for subaqueous work - Google Patents

Abstract

325,093. Formunt, J. A. Feb. 7, 1929. Piers; walls; piles, driving. - Sub-structures are placed below a pier or a like structure by inserting a caisson laterally under it, and maintaining the air pressure in the caisson; inside this sectional piles are driven so as to support the pier &c., and the caisson is finally filled with concrete. In preparation for underpinning the pier 1, a temporary pile 4 is driven equidistant from two piles 3 supporting the pier. A caisson consisting of a top plate 5 preferably of non-corrodible steel, a leading wall 6, and two side plates is lowered until the wall 6 is beneath the raft 2, and the chamber 9 and air-shaft 10 are attached. Compressed air is then forced in, and the soil under the wall 6 is removed. The caisson 5 is then gradually thrust forward by a winch 12 and rope 13, or by hydraulic or other means, the pile 4 and a cross-beam 28 being utilized for this purpose. The pile 4 is then cut down, and a permanent pile 16 utilized. These permanent piles consist of tubular sections of metal or concrete, and are pressed down in succession by a hydraulic ram 17, set between the roof 5 and the pile.' The earth &c. having been removed from the interior of the pile, it is filled with reinforcements and concrete. A packing-piece is then placed under the roof 5 and above the pile, and the space between the pile and the packing-piece is filled by fitting an inverted cup over the top end of the pile, end filling it with grout under pressure. When all the piles are driven and the load transferred to them, the whole of the caisson, except the chamber 9, is filled with reinforced or other concrete. When this is set, the shaft 10 and other parts are removed. The apparatus may be used to raise structures which have subsided.