Construction procedure for cast concrete wall below ground level uses vertical tube as trench shutter, destroyed when wall section has set

摘要

The procedure, in which a vertical trench is dug in the ground and a reinforcing element cage (3) is lowered into it prior to filling with liquid concrete, uses a tube (1) attached to the end of the cage by temporary ties (6) to act as shutting across the trench until the wall section has set. The tube is made from a material, e.g. a synthetic resin, that can be broken up by a digger when the next section of trench is excavated, and the reinforcing cage can be fitted with rollers to facilitate positioning the tube. The tube, or at least its lower end, can be filled with sand bags and gravel to resist the pressure of the concrete.