上海理工大学 光电信息与计算机工程学院，上海 200093
吴自雨，迟志鹏，李然，等. 多饱和态下的湿颗粒柱坍塌特性［J］. 中国粉体技术，2025，31（4）：1-11.
WU Ziyu， CHI Zhipeng， LI Ran， et al. Collapse characteristics of wet granular columns under multiple saturated states［J］. China Powder Science and Technology，2025，31（4）：1−11.
DOI：10.13732/j.issn.1008-5548.2025.04.010
收稿日期：2024-11-10，修回日期：2025-03-27，上线日期：2025-05-20。
基金项目：国家自然科学基金项目，编号：12072200，12002213；崂山实验室科技创新项目，编号： LSKJ202203507。
第一作者简介：吴自雨（1998—），男，硕士生，研究方向为颗粒流测量技术。E-mail：854831769@qq. com。
通信作者简介：杨晖（1981—），男，教授，博士，博士生导师，研究方向为颗粒流测量技术、大数据分析。E-mail： yangh_23@sumhs. edu. cn。
摘要：【目的】 为了探究降水量、土壤性质等因素对于山体坍塌的影响，预防山体滑坡等自然灾害。【方法】 构建含水颗粒柱坍塌模型，通过改变颗粒柱的含水量（质量分数），观察不同含水量对不同粒径颗粒柱坍塌模式及行为的影响；提出基于质心矢量位移法的方法，通过轮廓数字化提取技术，测定不同粒径、初始高宽比的颗粒柱在多种含水量条件下坍塌前后的质心矢量位移变化量，量化不同含水量下的液体对颗粒柱坍塌模式和沉积形态的影响。【结果】 含水量对颗粒柱坍塌行为的调控遵循抑制-平衡-促进的非单调规律，当含水量达到6%时，颗粒间的内聚力达到最大；利用质心矢量位移法发现，含水量的变化显著影响颗粒柱的重力势能转化率以及干湿颗粒柱质心位移模之比，含水量对这些参数的影响与颗粒柱的初始高宽比和粒径呈负相关关系。【结论】 含水量是影响颗粒柱坍塌模式的关键因素之一，湿颗粒柱的坍塌模式和坍塌行为受液体含量变化的影响。
Objective Landslide and debris flow are significantly influenced by precipitation distribution, mountainous topography, and soil granular properties. This study aims to explore the effects of various factors, such as moisture content and soil properties, on disaster behavior. A wet granular column collapse model is constructed to analyze how different moisture levels impact collapse modes and behavior, providing a theoretical basis for disaster prevention.
Methods This study investigated how moisture content affects the collapse modes and behavior of granular columns by systematically varying moisture levels from dry to fully saturated conditions. The experiments employed a custom horizontal transparent channel. The glass beads with diameters of 1. 0 mm and 2. 0 mm and a density of about 2，500 kg/m3 were used to form the granular columns. The initial aspect ratio, defined as the height-to-width ratio of the columns, varied between 1 and 3. Moisture content was controlled as the mass ratio of water to particles. The centroid vector displacement method was applied to analyze the role of liquid bridges in collapse dynamics across different saturation levels. A high-speed camera captured the collapse process at 3-millisecond intervals to ensure precise measurements.
Results and Discussion The collapse mode of granular columns with a particle diameter of 1 mm and an initial aspect ratio of 1 exhibited a non-monotonic transition under varying water content: initiating from continuous collapse in the dry state, progressing to blocked collapse at a water content of 2%, achieving static stability at 6%, reverting to blocked collapse at 8%, and ultimately returning to continuous collapse under over-saturated conditions with water content approaching 30%. This indicated that moisture content, along with aspect ratio and particle diameter, played a key role in determining collapse mode. The transition between collapse modes was driven by changes in liquid bridge forces. At low moisture content, liquid bridges enhanced particle cohesion, leading to blocked collapse. As moisture content increased, cohesion peaked at 6%, resulting in stability. Further increases in moisture content reduced cohesion, leading to blocked or continuous collapse. Calculation results from the centroid vector displacement method showed that moisture suppressed the vertical displacement of centroid and reduced the maximum kinetic energy during collapse compared to dry granular columns. Gravitational potential energy loss and kinetic energy changes were analyzed. For a granular column with a particle size of 1 mm and an initial aspect ratio of 1, when the water content is 2%, the gravitational potential energy loss rate is 27. 2%; when the water content is 6%, the granular column remains stationary; and when the water content increases to 8%, the column exhibits "slight and slow" block collapse， with a gravitational potential energy loss rate of less than 15%. By comparing the gravitational potential energy loss rates at different water contents, the intensity of block collapse can be quantitatively assessed. For 2 mm particles, the energy loss rate decreased with increasing moisture content. This study found that the influence of interstitial liquids on granular column collapse followed an increasing-stable-slightly decreasing trend as moisture content increased, with the maximum influence occurring at 6% moisture content. The ratio (Sr ) of the centroid displacement magnitude of wet columns to dry columns was defined, with larger Sr values indicating smaller reductions in centroid displacement due to moisture. Moisture content had a more significant impact on columns with smaller aspect ratios and particle diameters.
Conclusion Moisture content is a critical factor influencing granular column collapse. For sample S1, collapse modes transitioned sequentially with increasing moisture: continuous→blocked→stable→blocked→continuous collapse, proving that moisture determines collapse patterns. Analyzing collapse modes and gravitational potential energy loss revealed that 6% moisture maximizes liquid-induced cohesion. This identifies an optimal moisture range for stability, offering key insights into wet granular mechanics. A novel centroid displacement vector ratio was proposed to quantify energy conversion and liquid effects. Moisture not only alters the energy dissipation rates but also significantly affects the displacement ratio between wet and dry granular columns, with its influence inversely correlated to both the initial aspect ratio and particle diameter.
Keywords：wet particle; scaling law; centroid displacement; gravitational potential energy
［1］ZENG L, GE Y G, CHEN J G, et al. Influences of a debris flow disaster chain on buildings in remote rural areas, Southwest China［J］. Geomatics, Natural Hazards and Risk, 2022, 13（1）: 2777-2795.
［2］LI H C, GUAN Q Y, SUN Y F, et al. Spatiotemporal analysis of the quantitative attribution of soil water erosion in the upper reaches of the Yellow River Basin based on the RUSLE-TLSD model［J］. Catena，2022，212: 106081.
［3］CHENG X, SUN T-P, GORDILLO L. Drop impact dynamics: impact force and stress distributions［J］. Annual Review of Fluid Mechanics, 2022, 54: 57-81.
［4］KOSTYNICK R, MATINPOUR H, PRADEEP S, et al. Rheology of debris flow materials is controlled by the distance from jamming［J］. Proceedings of the National Academy of Sciences of the United States of America, 2022, 119（44）: e2209109119.
［5］GABRIELI F, LAMBERT P, COLA S, et al. Micromechanical modelling of erosion due to evaporation in a partially wet granular slope［J］. International Journal for Numerical and Analytical Methods in Geomechanics, 2012, 36（7）: 918-943.
［6］IVESON S M, LITSTER J D, HAPGOOD K, et al. Nucleation, growth and breakage phenomena in agitated wet granulation processes: a review［J］. Powder Technology, 2001, 117（1/2）: 3-39.
［7］JOMELLI V, BERTRAN P. Wet snow avalanche deposits in the French Alps: structure and sedimentology［J］. Geografiska Annaler: Series A, Physical Geography, 2001, 83（1/2）: 15-28.
［8］STARON L, LAJEUNESSE E. Understanding how volume affects the mobility of dry debris flows［J］. Geophysical Research Letters, 2009, 36（12）: L12402.
［9］JEROLMACK D J, DANIELS K E. Viewing Earth’s surface as a soft-matter landscape［J］. Nature Reviews Physics, 2019, 1（12）: 716-730.
［10］LAJEUNESSE E, MONNIER J B, HOMSY G M. Granular slumping on a horizontal surface［J］. Physics of Fluids, 2005, 17（10）: 103302.
［11］POLANÍA O, CABRERA M, RENOUF M, et al. Collapse of dry and immersed polydisperse granular columns: a unified runout description［J］. Physical Review Fluids, 2022, 7（8）: 084304.
［12］LAI Z Q, JIANG E H, ZHAO L J, et al. Granular column collapse: analysis of inter-particle friction effects［J］. Powder Technology, 2023, 415: 118171.
［13］TREPANIER M, FRANKLIN S V. Column collapse of granular rods［J］. Physical Review E, 2010, 82: 011308.
［14］SANTOMASO A C, VOLPATO S, GABRIELI F. Collapse and runout of granular columns in pendular state［J］. Physics of Fluids, 2018, 30（6）: 063301.
［15］XIAO H Y, HRUSKA J, OTTINO J M, et al. Unsteady flows and inhomogeneous packing in damp granular heap flows［J］. Physical Review E, 2018, 98（3）: 032906.
［16］JARRAY A, MAGNANIMO V, LUDING S. Wet granular flow control through liquid induced cohesion［J］. Powder Technology, 2019, 341: 126-139.
［17］ZHAO C, JIANG L L, LU X, et al. Analysis of wet soil granular flow down inclined chutes using discrete element method［J］. Water, 2019, 11（11）: 2399.
［18］RICHEFEU V, EL YOUSSOUFI M S, RADJAÏ F. Shear strength properties of wet granular materials［J］. Physical Review E, 2006, 73（5）: 051304.
［19］SCHEEL M, SEEMANN R, BRINKMANN M, et al. Morphological clues to wet granular pile stability［J］. Nature Materials, 2008, 7（3）: 189-193.
［20］MU F S, SU X B. Analysis of liquid bridge between spherical particles［J］. China Particuology, 2007, 5（6）: 420-424.
［21］WASHINO K, CHAN E L, MIDOU H, et al. Tangential viscous force models for pendular liquid bridge of Newtonian fluid between moving particles［J］. Chemical Engineering Science, 2017, 174: 365-373.
［22］ROSSETTI D, PEPIN X, SIMONS S J R. Rupture energy and wetting behavior of pendular liquid bridges in relation to the spherical agglomeration process［J］. Journal of Colloid and Interface Science, 2003, 261（1）: 161-169.
［23］ARTONI R, SANTOMASO A C, GABRIELI F, et al. Collapse of quasi-two-dimensional wet granular columns［J］. Physical Review E, 2013, 87（3）: 032205.
［24］GABRIELI F, ARTONI R, SANTOMASO A, et al. Discrete particle simulations and experiments on the collapse of wet granular columns［J］. Physics of Fluids, 2013, 25（10）: 103303.
［25］BOUGOUIN A, LACAZE L, BONOMETTI T. Collapse of a liquid-saturated granular column on a horizontal plane［J］. Physical Review Fluids, 2019, 4（12）: 124306.
［26］ABRAMIAN A, LAGRÉE P Y, STARON L. How cohesion controls the roughness of a granular deposit［J］. Soft Matter, 2021, 17（47）: 10723-10729.
［27］吴怡淞，王等明. 钟摆状态下湿颗粒坍塌流动行为及其动力相似性［J］. 计算力学学报，2022，39（3）：341-349.
WU Y S, WANG D M. Flow behaviors and dynamic similarity of wet granular collapse in the pendular state［J］. Chinese Journal of Computational Mechanics, 2022, 39（3）: 341-349.
［28］LI P S, WANG D M, WU Y S, et al. Experimental study on the collapse of wet granular column in the pendular state［J］. Powder Technology, 2021, 393: 357-367.
［29］XU X R, SUN Q C, JIN F, et al. Measurements of velocity and pressure of a collapsing granular pile［J］. Powder Technology, 2016, 303: 147-155.
［30］UTILI S, ZHAO T, HOULSBY G T. 3D DEM investigation of granular column collapse: evaluation of debris motion and its destructive power［J］. Engineering Geology, 2015, 186: 3-16.
［31］周龙. 基于离散元法的玉米种子建模及播种过程的仿真分析与试验研究［D］. 长春：吉林大学，2021.
ZHOU L. Discrete element method-based maize seed modeling and the simulation and experimental study of the sowing process ［D］. Changchun: Jilin University, 2021.
