Control de erosión y estabilización en talud con geosintéticos

Study cases
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Erosion control and slope stabilization with geosynthetics

Erosion control and slope stabilization with geosynthetics

Introduction

The Federal Electricity Commission (CFE) required a solution to stabilize a slope in which one of its electric power transmission towers is installed. Likewise, it required a fast and effective solution for erosion control that would eliminate the risk of landslides around the tower and that put its electrical infrastructure system at risk. The tower is located in a rainy area with difficult access, so a solution was required that did not require heavy equipment and that could be applied despite the weather conditions.

Trouble

They had very important erosion problems around the base of a CFE electric power transmission tower. A masonry wall had been placed that overturned due to its poor foundation, poor management of surface drainage, and poor quality of the soil retained by the wall. When the masonry wall overturned, the erosion problem worsened causing the loss of soil in two of the supports of support of the tower, putting it at risk of collapsing.

The challenge

The project site is located in a mountain area with constant rainfall throughout the year, without regular access to vehicles or cargo equipment, so access to materials and equipment would be limited.

Solution

The use of roll concrete Concrete Canvas®, Mirafi® TM erosion control mantle, Platipus® anchors Y Lurran® Geocostals It was ideal for being materials with a simple and fast installation process compared to traditional methods; in addition to being considerably lighter, facilitating its transportation and handling to the project site. These geosynthetic materials can be installed in adverse weather conditions and in this case only a 3.5 ton truck was required for transportation, so the access problem was no longer an impediment.

The system proposed as a solution sought to restore the soil washed away by erosion in order to protect the bases of the tower, waterproof the base and the immediate surroundings of the tower, direct the water collected from rain to areas that did not compromise the slope and reduce the runoff speed on the slope down the tower to avoid progressive erosion processes that will lead to destabilization.

Process

For the works, an access was sought for a team that could transport the heaviest material, the Concrete Canvas®, and facilitate installation maneuvers.

The first step was to restore the washed soil, for which a substantially horizontal and embedded platform was built at the foot of the affected slope, where the soil confined to Lurran® Geocostals to avoid immediate erosion caused by rain.
The concrete blocks were prepared to protect the tower bases.
Next, the crest of the hill where the tower is founded was covered with the mantle of rolled concrete. Concrete Canvas®, to a perimeter gutter that will allow us to capture, conduct and evacuate rainwater.
Through the Concrete Canvas® the anchors were placed Platipus® S6 Args 3.5 meters deep according to the design proposal to stabilize the slope and prevent new landslides. These anchors were installed with the help of a mostly pneumatic rotary hammer, although some of these were also installed manually.
Subsequently, the erosion control mantle was placed Mirafi® TM14S in the lower part of the slope with the intention of reducing the runoff speed of the rainwater captured in this area and on the roof by the Concrete Canvas®, and also to avoid an erosive process in this area that could put the tower at risk in the future. This mantle allows the growth of vegetation, ensuring the long-term operation of the protection in this area, combining the geosynthetic with nature.
Through the Mantle Mirafi® TM14S the Platipus® S2 anchors Geo, designed for the immediate subjection of the synthetic mantle to the soil of the natural slope, improving resistance to cutting. These materials make up a high performance erosion control system and anchors to be applied in slope projects with these types of conditions.

The results

The installation was carried out with a work team of 8 people over 3 weeks including all the works. As mentioned at the beginning, the climate was a factor against it, since half of the period in which it was worked there were sporadic rains and some greater ones that made it difficult to enter the site and obviously the execution of the works. However, there were no significant delays to final delivery on time.

conclusion

The project was concluded in a timely manner, demonstrating the technical capabilities of geosynthetic engineering design, the ease of application of these systems and the speed of installation of the applied materials: roll concrete Concrete Canvas®, Mirafi® TM permanent synthetic erosion control mantles, Platipus® anchors, Y Lurran® Geocostals.

Technical aspects

Location: Teziutlán, Puebla.
Builder: Imperlife.
Design Engineers: G&G Technical Office.
Products Concrete Canvas® CC5, Mirafi® TM14S, Platipus® S2 Geo and S6 Args, Lurran® Geocostals.
Geosynthetics Manufacturer: Concrete Canvas Ltd., TenCate Geosynthetics NA, and Platipus Anchors, Inc.