Cota, a town and municipality in Colombia situated 26 kilometers away from Bogota, has experienced significant urban growth in recent years. Once a vegetable and potato growing area, Cota is now filled with houses and new development projects. However, the winter season has caused flooding and unpleasant odors due to the overflowing of the sewer and stormwater systems. For over 50 years, the residents of Cota have been waiting for a much-needed renovation of the sewage networks.
In 2016, the mayor of Cota at the time, Carlos Julio Moreno, announced a significant investment of nearly $40 billion COP ($10.65 million USD) for the construction of a stormwater system and the rehabilitation of the sewer system.
"Our commitment is big and we will improve the quality of life and the competitiveness of our area with more than 30,000 inhabitants and another 40,000 people who commute to the industrial zone here," said Carlos Moreno in 2016. The contract for the project was signed by Consorcio Colector Sur on December 27, 2016, with a total value of $44,490,445,195 COP ($11.87 million USD). The project was scheduled to begin on July 11, 2017, and be completed by July 10, 2019. It also included the separation of pipelines, so one system would carry rainwater to the Bogota River, and the other would transport sewage to the Municipality's Wastewater Treatment Plant.
However, concerns arose when residents began to notice cracks in their homes and land due to heavy machinery work on Carrera 2, the first major construction front that used trenches to install the pipeline. Arles Osorio, a homeowner near the construction site, shared his experience: "I was fixing and remodeling my house. But the construction began and the terrain started to fault. Now I can't even open the doors or windows of my house."
When trenching began parallel to Carrera 5, Cota's main road and a national road, the road started to crack, prompting construction to halt for evaluation. This is when Petra stepped in to offer a less invasive and more structurally sound alternative.
The final proposal from Petra, which was a subcontractor to Aqua Ingenieros, was a combination of Hand Mining and Petra's Assisted Dynamic Boring (ADB) module in its Petra Platform. The total project cost was $7.8 billion COP ($2.08 million USD). Another contractor proposed a microtunneling solution costing nearly $20 billion COP ($5.33 million USD). By employing our innovative ADB technology, Petra successfully contributed to the long-awaited improvement of Cota's sewage and stormwater systems, demonstrating our ability to provide cost-effective and efficient solutions for large-scale infrastructure projects.
The launch shafts were made with reinforced concrete, in the following dimensions: 2.5 m (width) x 9 m (length) x 3 m (depth). Due to the diameter of the metal casings, the ADB 42" was used in this specific project.
