Huánuco, located in central Peru, is an important center of agro-industrial and mining production in the country and its geographic location imposes great challenges for its road communication with the rest of the country and the continent. For this reason, the Huánuco - La Unión - Huallanca Dv Antamina/Emp. PE - 3N (Tingo Chico) - Nuevas Flores - Llata - Antamina roadway corridor was created in the year 2012 as part of a roadway infrastructure improvement project in the region, with the goal of improving the connectivity and transportation conditions of the area, as well as fostering economic and social development.
In support of its conservation and improvement, WSP Perú is working together with Consorcio Supervisor Louis Berger - HOB to supervise the improvement, conservation and operation works of the roadway corridor.
The tunnel is built on limestone with some alternation of thin siltstone layers, and has an average height of 3,437 m.a.s.l. During specific seasons of the year, there are great rainfall events in the area, which represents a challenge for the construction team.
The construction procedure employed is the conventional method of drill and blast, which is carried out in two stages: the upper part of the section, called TOP HEADING, with a height of 5.60 meters, and then the lower part of the section, called BENCH, which reaches the ground level of the tunnel.
Currently, the construction of the heading has progressed by 54.33%, which represents 318.90 meters. The excavation of the bench is being done as the heading excavation progresses. The bench is approximately 180 meters behind the heading. The shotcrete and the anchor bolts are being placed as the excavation progresses, bearing in mind the self-support time of each geological condition.
The role of WSP in the project consists in supervising the construction of the tunnel and ensuring the rigorous compliance with the drawings and the technical specifications, as well as the construction schedule and budget agreed for the works.