Q. Illustrate Shaft grouting for friction barrettes?
For the construction of friction barrettes, some grout pipes are designed at periphery of the barrettes. Within a short duration (for example 24 hours) of concreting of barrettes, fresh concrete cover is cracked by injecting water. Subsequently shaft grouting is conducted where grout travels along the interface between concrete and soil and compacts the surrounding soils that are loosened or disturbed during excavation. Hydraulic fracturing of surrounding soils by grout during the grouting operation produce planes of higher shear strength. The grout will penetrate and improve the strength of soils around barrettes.