The new Rio Metro Line 4 aims to connect Barra da Tijuca (West Zone) to the Ipanema neighborhood where the current subway system is already in operation. This specific section, known as Line 4 South, will connect the General Osorio Station in Ipanema to a new future station located in the Gavea neighbourhood. This line will also create a connection to the Barra da Tijuca neighbourhood. In total, Line 4 South will add approximately 5km of tunnels; three new stations located at the Nossa Senhora da Paz Square, Alah Garden, and Antero de Quental Square; and one emergency exit at Igarapava Street.
Line 4 South is entirely underground, having been excavated by a tunnel boring machine (TBM) in the section between General Osório and Gávea Station. The three new stations (Nossa Senhora da Paz, Jardim de Alah e Antero de Quental) were constructed using the “cut-and-cover” method, in order to generate the least interference possible. Its implementation required diaphragm walls and ground treatment with jet grouting.
Arup was hired to perform a multidisciplinary design review of the Rio Metro Line 4 South expansion, including temporary structures, detailed review of the drawings, structural calculations and tunnels, independent structural analysis, and conceptual checks of other disciplines including architecture, mechanical, electrical, and fire.