The Petra LATAM team was tasked with installing a wastewater pipeline under the Tunjeulo River in Bogota, which would connect to a large sewer line collector. The primary goal of this project was to help clean the river and improve the sanitation of the nearby Britalia neighborhood. Prior to our intervention, Britalia was not connected to the wastewater system, and as a result, sewage was being mixed with stormwater and discharged into the Rio Tunjuelo, which in turn fed into the Bogota river.
The main purpose of the project was to separate wastewater from stormwater, which required the installation of a comprehensive wastewater network separate from the existing stormwater infrastructure. This involved creating 22 distinct drives and sections between manholes to collect all wastewater and channel it to the collector pit.
From the collector pit, the wastewater needed to be transported underneath the river to an existing wastewater collector. To accomplish this critical part of the project, our proprietary trenchless machine, Petra Platform using our Pilot Guided and Assisted Dynamic Boring (ADB) modes, was employed to cross the river and connect to the sewage collector.
As the last drive of this gravity line installation, the phase of the project presented several unique challenges due to its location at the lowest point of the project. This meant that we had to perform the installation very precisely, with less than 1 meter of cover between the bottom of the river and top of the pipe. The wastewater collection point had to be situated at the deepest point, and this, combined with the river's elevation less than a meter above the pipe and the permeable sandy terrain, resulted in a very difficult project. Compounding this was the significant water pressure. When mixed with water under high pressure, the sand could behave like a liquid, causing liquefaction, posing an additional challenge for any trenchless machine. Furthermore, because of years of garbage buildup, our trenchless machine continuously encountered compacted trash when boring through the ground.
Despite these obstacles, our team successfully completed the piloting process without any issues and on schedule. We then proceeded to install a 16-inch casing to complete the trenchless crossing and connect the wastewater pipeline to the existing collector chamber, ultimately fulfilling the project's objectives and improving the environment for the residents of Britalia and beyond. This project is ongoing and will be completed with a 36” product pipe within a 42-inch final casing.
Below you will find images from the job and some techniques we used to successfully accomplish the bore, despite the nightmare conditions.
