GB1309360A - Watertight wall - Google Patents

Abstract

1309360 Subterranean barrier walls SOLETANCHE SA 7 Sept 1971 [15 Oct 1970] 41716/71 Addition to 1284856 Heading E1H A watertight barrier wall is formed in the ground by casting into a trench 3 as it is cut a hardenable slurry 7 containing between 16 and 30, preferably 23kg of bentonite and 160 and 300, preferably 230 kg of cement per cubic metre, the rate of hardening of the slurry being such that during the first 48 hours after casting its viscosity is no greater than 20 centipoise and its tensile strength no greater than 5g/cm<SP>2</SP>. Prefabricated concrete parts e.g. pillars 4, 5 and panels 6, adjacent surfaces of which are spaced at least 0.01m. and preferably 0.05m. apart are during this period lowered into the slurry filled trench. Preferably the tensile strength of the hardening slurry remains between 150 g/cm<SP>2</SP> and 1.5 kg/cm<SP>2</SP> between the fifth and fifteenth day after casting. To form an elongated wall, a first group 3, 8 of such trenches are cut at spaced intervals and filled with the slurry and the prefabricated parts e.g. 5, 9, and then when the slurry in these trenches has attained a tensile strength greater than 150 g/cm<SP>2</SP> and a sufficient viscocity as not to flow into a neighbouring trench, a second group 10 of intermediate trenches which overlie the ends of the trenches of the first group are cut and the exposed outer edges of the pillars 5, 9 cleaned of excess hardening slurry. Slurry 14 and prefabricated pillars and panels 11, 12, 13 are then placed in the second group of trenches, the slurry 14 in these latter trenches bonding with the hardening slurry in the first group of trenches to form an impervious jointless barrier wall. In a modification (Fig. 7 not shown) the prefabricated parts comprise adjacent but spaced tongue and grooved panels. The earth adjacent a finished wall may be excavated to expose one wall face.