Work to build the new Ollachea tunnel, located on the Inambari-Azángaro section of the Interoceánica Sur highway, is 79.2% complete with an executed investment of USD 18,233,853.74, according to Peru’s Organismo Supervisor de la Inversión en Infraestructura de Transporte de Uso Público (Ositrán).
The infrastructure, which spans kilometers 231.7 to 232.8 at the height of the Ollachea district in the province of Carabaya, in Puno, is over one kilometer long (1,025 meters). It was designed to avoid the area of constant landslides from the upper part of the slope that have been occurring since 2013; in this way, the route will provide users with better road safety and trafficability conditions.
The construction of the Ollachea tunnel consisted of two components or stages: the first included drilling and excavation work, paving, drainage works, and civil works that were completed in May 2024. The second component, currently under execution, consists of electromechanical installations (ventilation, lighting, control systems, signage, etc.) and safety features that should be completed in December of this year.
Ositrán’s supervision from the start of the tunnel’s construction involved a team of specialist engineers, as well as technical equipment for quality and laboratory controls. During the first component, various tests were carried out on a permanent basis to ensure the quality of the functional and structural characteristics of the infrastructure under execution; as well as environmental control, among others.
The supervision to ensure compliance with the quality of the execution of the second component has been using diverse equipment for the due controls of the electromechanical installations.
For the excavation work of the Ollachea tunnel, it was necessary to use explosives in areas of terrain that warranted it. Mechanical methods were also used, employing various specialized machinery. For the structural lining of the tunnel, flexible supports consisting of shotcrete, bolts, and metal frames based on the principles of the New Austrian Tunneling Method (NATM) were applied.
