Downslope Weakening of Soil Revealed by a Rapid Robotic Rheometer
Downslope Weakening of Soil Revealed by a Rapid Robotic Rheometer
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DOI：
10.1029/2023gl106468
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发表时间：
2024-01
影响因子：
5.2
通讯作者：
John G. Ruck;Cristina G. Wilson;Thomas F. Shipley;Daniel Koditschek;Feifei Qian;D. Jerolmack
中科院分区：
文献类型：
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作者：
John G. Ruck;Cristina G. Wilson;Thomas F. Shipley;Daniel Koditschek;Feifei Qian;D. Jerolmack
从山坡往下走，从一个山脊到另一个山谷，土壤会发育，并变得越来越风化。粘土含量、有机质和孔隙度的下坡变化会引起土壤强度的相应变化，从而影响边坡的稳定性和侵蚀。然而，这一点尚未得到证实，因为土壤流变学的现场测量具有挑战性，而且很少见。在这里，我们使用机械腿作为机械敏感和时间效率高的渗透仪，沿着典型的温带山坡剖面绘制土壤强度图。我们观察到土壤强度的系统性下坡减弱和增加的异质性，与从富含沙粒的脊状材料到粘性谷底土团聚体的过渡有关。风化引起的土壤成分的变化导致粘性土壤中物理上不同的力学行为，这与在砂土中观察到的行为不同。我们还展示了腿部机器人可以在复杂的环境中使用四肢来感知和提高机动性的前景，这对行星探索具有重要意义。
Moving down a hillslope from ridge to valley, soil develops and becomes increasingly weathered. Downslope variation in clay content, organic matter, and porosity should produce concomitant changes in soil strength that influence slope stability and erosion. This has yet to be demonstrated, however, because in situ measurements of soil rheology are challenging and rare. Here we employ a robotic leg as a mechanically sensitive and time‐efficient penetrometer to map soil strength along a canonical temperate hillslope profile. We observe a systematic downslope weakening, and increasing heterogeneity, of soil strength associated with a transition from sand‐rich ridge materials to cohesive valley bottom soil aggregates. Weathering‐induced changes in soil composition lead to physically distinct mechanical behaviors in cohesive soils that depart from the behavior observed for sand. We also demonstrate the promise that legged robots may use their limbs to sense and improve mobility in complex environments, with implications for planetary exploration.