Resilient Infrastructure Slope Protection to Prevent Earthwork Failures
Railway systems commonly face a range of technical challenges when it comes to managing earthworks assets. Some of the challenges include exposure to prolonged wet weather and extreme weather events, increased embankment traffic loading, effects of vegetation on soil and rock slopes and impacts of climate change.
ARMORMAX® is an innovative solution for infrastructure slope stabilisation that provides vegetated reinforcement, improves the factor of safety, and significantly reduces the probability of failure. The system is composed of engineered earth anchors that are designed and tested for compatibility and performance with Propex’s High Performance Turf Reinforcement Mat (HPTRM) to increase slope stability for up to 75 years.
The Reinland Channel case study illustrates how ARMORMAX provides weather-resilient slope protection to prevent earthwork failures for long-term results.
The Reinland Drain is a municipal drainage channel in Manitoba, Canada that receives flows from the entire Pembina Valley. The channel’s sandy, silty clay soil could not handle the flow from a 100-year storm event. Years of erosion, combined with damage from significant flooding, caused major failures to three kilometres of the channel. The town needed to stabilise the eroded channel banks to prevent further flooding and shoreline loss.
Due to wet weather, the construction schedule was delayed until the winter months. This delay drastically shortened the allotted construction schedule because the project had to be completed before the start of the spring run-off in March.
Originally, the project design called for a combination of reno mattresses on the bottom of the channel with rock riprap on the side slopes. Rock riprap had previously been used in the channel but had failed during rain events. Another challenge of using rock was transporting it to the project site. The closest quarry was 90 minutes away and shipping the amount of rock needed would add considerable time and cost. Propex worked with the project engineer to value engineer ARMORMAX in place of the rock riprap.
One truckload of 20,000 square yards of HPTRMs is equivalent to 667 truckloads (6,667 cubic yards) of rock riprap. The ability to expedite materials to the job site, and ARMORMAX’s easy installation, enabled the team to complete the project within the narrow timeline. In rail applications, this means minimal disruptions to train services when repairing a failed slope and offers a proactive approach to prevent future track closures for up to 75 years.
Use of an ARMORMAX over rock riprap reduced Reinland’s overall project cost by nearly 30 percent and lowered carbon emissions by 90 percent. ARMORMAX’s carbon footprint has been independently verified and is up to 30 times lower than rock riprap and concrete-based solutions.
Once installation is complete, ARMORMAX promotes vegetated reinforcement. The system is engineered with a trilobal design that locks seeds and soil in place to promote rapid root development for long-term vegetation. This helps to decrease sedimentation and pollutants and encourages infiltration of water back into the ground water table. These are two reasons why the Environmental Protection Agency (EPA) has identified systems that utilise HPTRMs like ARMORMAX as a Best Management Practice (BMP) for improving water quality. Conversely, rock does not promote vegetation and offers poor filtering and pollutant-removal capabilities.
Within six months, the channel was vegetated. Currently the system has been in place for two years and has experienced major weather and flood events, without any failure. An additional benefit of a vegetated design is that it is more graffiti-resistant than a concrete or rock-based solution.
ARMORMAX has been tested and approved by the U.S. Corps of Army Engineers, and more than 20 million square metres have been installed across the globe. For more than a decade, this technology has been used to reinforce embankments and slopes to protect transportation infrastructure.
For more information about ARMORMAX or to inquire about our next webinar, please contact Randy Thompson at [email protected]
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