GB270041A - Improvements in and relating to concrete linings for shafts, wells and other shaft-like structures - Google Patents

Abstract

270,041. Blandford, T., and Gee, A. March 2, 1926. Shafts and wells.-A concrete lining for shafts, wells, and other shaft-like structures comprises a body of concrete cast in situ in contact with a back sheeting adjacent the ground and reinforcements, wholly embedded in the concrete, spaced from the back sheeting and unconnected thereto. The reinforcement may be arranged only in the half or third of the thickness of the concrete remote from the back sheeting. As excavation proceeds, corrugated iron sheets 1 are placed against the ground and held by iron rings 3 and wedges 4, lower rings 3 being supported from upper rings by hooks 5. After a desired depth is reached, a water garland 6 is built round the bottom of the sheeting 1, the garland comprising a wooden ring carrying a vertical iron ring; pipes 7 remove the water from the garland'. A wedge 8 is then cut out of the ground and a timber packing 9 laid on the shaft bottom. A steel base ring 10 is laid on the packing 9 and vertical angle irons 12 are placed in pockets in the ring 10, aligned angle irons 12 being connected by fish plates. Circumferential reinforcements 13 are threaded through apertures in the angle irons 12 and their ends are connected by a wired lap joint. Bars 18 on the rings 3, clamps 17 bolted to the angle irons 12 and engaging the bars 18, and lacing bars 19, secured to the bars 18, form temporary supports for the reinforcements 12, 13. Shuttering 16 is then built on the base ring 10 which is further provided with a footing of sand. Concrete is then filled in up to the garland 6, and after this concrete has set, broken brick covered with thick cement is filled in between the garland 6 and the corrugated sheeting 1. Further shuttering 16 is then erected and concreting continued in desired steps, the rings 3. wedges 4, bars 18, clamps 17, and lacing bars 19 being removed as the concreting is effected. On reaching the bottom of the previously finished portion of the lining, overlapping shuttering is provided to make the joint, and one or more pipes are passed through the shuttering and sheeting at 1 at this part; concreting is then completed and when the concrete has set, liquid cement is forced through the pipes 7 till all flow of water through the upper pipes has ceased ; after further setting, further cement may be injected at high pressure and the pipe 7 temporarily sealed. A further length of shaft is then excavated and lined, angle irons 12 of adjacent lengths being connected by fish plates. At intervals, permanent garlands 20 are provided, the shaft being widened at these points to give a uniform thickness of lining.