Terraforce Block Reinforced Soil System Creates Space, at Minimum Cost, for Pumping Station at Dartford, Kent.  The pumping station at Horton Kirby was constructed as part of The Thames Water Utilities Borehole Commissioning Scheme. The level and position of the pumping station required the existing ground to be lowered, generating the need for a steep slope along the site boundary.

Soil Conditions
The geology of the site consisted of in-situ weathered London Clay.

Solution
A Terraforce Block faced reinforced soil system was used to provide a very economical solution and to satisfy the external stability of the slope. Geotextile reinforcement layers were placed between the blocks at regular vertical intervals and extended back into a granular fill to provide a reinforced soil block. The hollow block courses were stepped in tiers to give a 55o face angle, and were filled with topsoil to form planting pockets.

Construction
Construction of the Terraforce block wall involves preparation of a concrete levelling strip. The first row of blocks are placed and aligned. A drainage pipe is positioned behind the first row of blocks with the outlet suitably placed to enable connection to the main drainage system. The blocks are then filled with a good quality topsoil, and a well graded granular fill is placed behind up to the level of the first block. A layer of geotextile reinforcement is trapped in place by a further two lifts of blocks above. The whole process is repeated while backfilling with the granular fill.