Study on the Morphological Changes of Sandstone Particles under Freeze-Thaw Cycles and the Long-Term Effects of Provenance Accumulation in Debris Flows in Motuo,Xizang
Xia Yangyang
Zhang Gen
Shen Chenming
Yu Haibing
Li Pengyu
Bi Haolin
Yangjin Zhuoma
Abstract：Freeze-thaw weathering can cause sandstone fragmentation,alter its mechanical properties,and serve as the provenance supply for debris flows.This study aims to simulate the effects of freeze-thaw weathering on sand-stone fragmentation and provenance accumulation in debris flows in Motuo through the freeze-thaw cycle test on re-molded sandstone samples.The test was conducted in a subtropical humid weathering zone.After 0、10、50 and 100 freeze-thaw cycles(FTU),the long-term strength and morphological indicators of the samples were measured using a spherical template indenter and a particle image analyzer.The selected morphological indicators-equivalent diam-eter and fractal dimension-showed a strong correlation with long-term strength.The freeze-thaw cycling process al-tered the fragmentation degree of the remolded sandstone samples,resulting in distinctive particle shape characteris-tics.By analyzing the factors influencing the provenance accumulation of remolded sandstone samples under freeze-thaw conditions,it is concluded that the provenance accumulation process of sandstone-supplying debris flows un-der freeze-thaw conditions follows a cyclic freeze-thaw accumulation pattern.Based on this,corresponding disaster prevention and mitigation countermeasures are proposed.
Keywords：SandstoneFreeze-thaw cycleLong-term strengthParticle fragmentationDebris flow
Publication Date：2025-09-30
Online Publishing Date：2025-10-14(First online date of this platform, not the publication date of the document)
Pages：15( 54-68 )