Along developed riverbanks, physical barriers can help contain flooding and combat erosion.
Along developed riverbanks, physical barriers can help contain flooding and combat erosion. In arid regions, check dams can help retain soil after rainfall and restore damaged landscapes. In construction projects, metal plates can provide support for excavations, retaining walls on slopes, or permanent foundations. All of these applications can be addressed with the use of sheet piles, elements folded from flat material and driven vertically into the ground to form walls and stabilize soil. Proper soil stabilization is key to sustainable land management in industries such as construction, mining, and agriculture; and land degradation, the loss of ecosystem services from a given terrain, is a driver of climate change and is estimated to cost up to $10 trillion annually.
With this motivation, a team of roboticists at Harvard’s Wyss Institute for Biologically Inspired Engineering has developed a robot that can autonomously drive interlocking steel sheet piles into soil. The structures that it builds could function as retaining walls or check dams for erosion control. The study will be presented at the upcoming 2019 IEEE International Conference on Robotics and Automation.
Conventional sheet pile driving processes are extremely energy intensive. Only a fraction of the weight of typical heavy machinery is used for applying downward force. The Wyss team’s “Romu” robot, on the other hand, is able to leverage its own weight to drive sheet piles into the ground. This is made possible by each of its four wheels being coupled to a separate linear actuator, which also allows it to adapt to uneven terrain and ensure that piles are driven vertically. From a raised position, Romu grips a sheet pile and then lowers its chassis, pressing the pile into the soil with the help of an on-board vibratory hammer. By gripping the pile again at a higher position and repeating this process, the robot can drive a pile much taller than its own range of vertical motion. After driving a pile to sufficient depth, Romu advances and installs the next pile such that it interlocks with the previous one, thereby forming a continuous wall. Once it has used all of the piles it carries, it may return to a supply cache to restock.
Read more at Wyss Institute for Biologically Inspired Engineering at Harvard
Image: The robot is designed by Wyss Institute researchers to drive interlocking sheet piles into granular soils like sand on a beach. (Credit: Wyss Institute at Harvard University)
