Reformation and Revegetation of Two Steep Cut Slopes Using Jute Bags, on a Road in Tayacaja, Peru

Discover the transformative approach of using **biodegradable jute bags** for slope stabilization in the high-altitude terrains of Tayacaja, Peru. In our groundbreaking study, we successfully reformed and revegetated two steep cut slopes previously used as a construction material quarry, meeting stringent environmental standards. This innovative method not only enhanced slope stability but also facilitated natural vegetation growth, proving its resilience through intense seasonal rains. Ideal for environmental engineers and sustainability advocates, our project sets a new standard in eco-friendly erosion control and land rehabilitation. Dive into our comprehensive research to explore how jute bags can revolutionize your next green infrastructure project.

Full Abstract: This paper presents the activities undertaken for the reformation of two cut slopes that were utilized as a quarry for construction material for a road serving a hydroelectric power plant in the Tayacaja region, Huancavelica department, in central Peru, at an elevation of 3000 meters above sea level. Upon the completion of their use as a quarry, the Peruvian environmental authority (OEFA) noted that the reformed slopes did not meet natural conditions, and thus required a new reformation and revegetation process to reduce erosion, enabling them to grant environmental compliance approval.

Problem Faced
The challenge encountered was that reformation by soil placement on such steep slopes was unfeasible. The static and pseudo-static safety factors were below the parameters established by the standards, indicating that soil placement could not continue due to the risk of material collapse. Consequently, the requirement of the environmental authority could not be fulfilled as the slope protection was insufficient.

Evaluation of Reformation Systems
Three systems were analyzed for the reformation process:
1. Installation of Gabions: These are wire mesh boxes filled with stones, used for erosion control and stabilization.
2. Use of Tires as a Reformation Mechanism: Old tires could be used to build terraced structures on the slopes.
3. Installation of Jute Bags: This method involves filling biodegradable jute bags with soil and placing them on the slope.

The chosen method was the use of jute bags because they significantly improved the static and pseudo-static safety factors. Jute bags could be positioned according to the gradient of the slope, adapt to the terrain shape, be manipulated as the fill level increased, be compacted, and additionally, could support revegetation.

Implementation
The material used to fill the jute bags was alluvial soil from the cleaning of road drains. The bags were placed in contour rows from the bottom up, gaining height and increasing the soil volume progressively. Once the maximum possible height was reached, a perimeter drainage system was installed to capture water from the slope.

Revegetation Process
Revegetation started after the structural stabilization, using both forage grass seeds and cuttings of native plants at high density.

Timeline and Results
The works commenced in August 2023, during the dry season in the region, and continued through the rainy season from November 2023 to April 2024, during which the project area experienced an average rainfall of 97 mm/year. The precipitation during these months did not adversely affect the reformed slopes stabilized with jute bags, demonstrating the effectiveness of the implemented methodology. The substantial growth of vegetation during this period further reinforced the slope stability.

Conclusion
This detailed account highlights the innovative use of jute bags for steep slopes stabilization and revegetation in challenging conditions, demonstrating a successful method for erosion control and environmental compliance in steep, unstable terrains.
With these results, the environmental authority acknowledged the completion of the reformation and revegetation commitment.