Aiming to ensure the durability and continuous improvement of a building, groundwater lowering techniques have become fundamental and have evolved over the years to meet the new demands of construction. For the construction of line 4 of the Rio de Janeiro subway, it was necessary to carry out a provisional system of lowering the water table at the Jardim Oceânico station. In all there were six stations (Oceanic Garden, São Conrado, Gávea, Antero de Quintal, Jardim de Alah and Nossa Senhora da Paz). In this work, the main function of the temporary groundwater lowering system was to significantly reduce lateral thrust on the side retaining walls used for excavations, eliminating water pressures (by pressure) on them, and to ensure the stability of the excavations. for the bottom rupture without having to deepen the walls the retaining walls (diaphragm walls), which in turn have a thickness of 80 cm. Geotechnical profile under study showed a sandy substrate with depths in the order of 35m to 40m, with free water source (Marapendi channel) very close to the excavation site where it can considerably increase the drained flow rates. A pumping test was performed prior to the installation of the water table pumping system where it was possible to obtain the average subsoil permeability of the region, with adequate precision to achieve a more efficient and economical setting for the lowering system from the water table.
Menu