Agliardi Federico, Scuderi Marco M, Fusi Nicoletta, Collettini Cristiano
Department of Earth and Environmental Sciences, University of Milano-Bicocca, Piazza della Scienza 4, 20126, Milano, Italy.
Department of Earth Sciences, La Sapienza University of Rome, Piazzale Aldo Moro 5, 00185, Roma, Italy.
Nat Commun. 2020 Mar 12;11(1):1352. doi: 10.1038/s41467-020-15093-3.
Giant rockslides are widespread and sensitive to hydrological forcing, especially in climate change scenarios. They creep slowly for centuries and then can fail catastrophically posing major threats to society. However, the mechanisms regulating the slow-to-fast transition toward their catastrophic collapse remain elusive. We couple laboratory experiments on natural rockslide shear zone material and in situ observations to provide a scale-independent demonstration that short-term pore fluid pressure variations originate a full spectrum of creep styles, modulated by slip-induced undrained conditions. Shear zones respond to pore pressure increments by impulsive acceleration and dilatancy, causing spontaneous deceleration followed by sustained steady-rate creep. Increasing pore pressure results in high creep rates and eventual collapse. Laboratory experiments quantitatively capture the in situ behavior of giant rockslides and lay physically-based foundations to understand the collapse of giant rockslides.
巨型滑坡分布广泛且对水文强迫敏感，尤其是在气候变化情景下。它们会缓慢蠕动几个世纪，然后可能会灾难性地失稳，对社会构成重大威胁。然而，控制其向灾难性崩塌从缓慢到快速转变的机制仍然难以捉摸。我们将天然滑坡剪切带材料的实验室实验与现场观测相结合，提供了一个与尺度无关的证明，即短期孔隙流体压力变化会引发一系列完整的蠕变样式，并受滑动引起的不排水条件调制。剪切带通过脉冲加速和剪胀响应孔隙压力增加，导致自发减速，随后是持续的稳定速率蠕变。孔隙压力增加会导致高蠕变速率并最终崩塌。实验室实验定量地捕捉了巨型滑坡的现场行为，并为理解巨型滑坡的崩塌奠定了基于物理的基础。
