冻融作用下青藏粉土颗粒尺寸与形态变化规律研究  

Study on particle size and morphology of Qinghai-Xizang silt under freeze-thaw action

作　　者：翟金榜 张泽 张圣嵘[2,3] Andrey MELNIKOV 杨雪 ZHAI Jinbang;ZHANG Ze;ZHANG Shengrong;Andrey MELNIKOV;YANG Xue(School of Transportation/Institute of Cold Regions Science and Engineering,Northeast Forestry University,Harbin 150040,China;School of Civil Engineering,Northeast Forestry University,Harbin 150040,China;Northeast-China Observatory and Research-Station of Permafrost Geo-Environment of the Ministry of Education,Harbin 150040,China;Melnikov Permafrost Institute,Siberian Branch,Russian Academy of Sciences,Yakutsk 117997,Russia)

机构地区：[1]东北林业大学交通学院/寒区科学与工程研究院,黑龙江哈尔滨150040 [2]东北林业大学土木工程学院,黑龙江哈尔滨150040 [3]东北多年冻土区地质环境系统教育部野外科学观测研究站,黑龙江哈尔滨150040 [4]俄罗斯科学院新西伯利亚分院梅尔尼科夫冻土研究所,俄罗斯联邦雅库茨克117997

出　　处：《冰川冻土》2023年第5期1544-1554,共11页Journal of Glaciology and Geocryology

基　　金：科技部国家级外专项目(高端外国专家引进计划)(G2021131003L);国家自然科学基金项目(41771078);国家自然科学基金委员会(NSFC)与俄罗斯基础研究基金会(RFBR)合作交流项目(42011530083);黑龙江省交通投资集团有限公司科研项目(JT-100000-ZC-FW-2021-0129)资助。

摘　　要：冻融循环导致颗粒破碎和团聚的过程中,将会显著改变颗粒的尺寸和形态。为研究冻融循环对颗粒尺寸和形态的影响规律,试验选用青藏粉土为研究对象,分别进行0、1、5、10、50、100次封闭系统下的自由冻融循环试验。对冻融后的试样采用移液管法进行粒度成分测试后,采用PIP9.1型颗粒图像处理仪进行长径比、圆度等颗粒形态参数测试分析。试验结果表明:冻融作用导致颗粒的棱角边缘发生破碎,粒径小于0.001 mm的颗粒质量百分比增大。颗粒长径比主要分布在1~3之间,占比94%以上,且长径比的半对数柱状图符合正态分布。圆度分布在0.09~1之间,且100次冻融循环后颗粒的平均圆度增大。100次冻融循环后,颗粒的长径比及尺寸减小,圆度增大,颗粒形状趋近于圆形。整体发现经过冻融的过程中青藏粉土颗粒在发生团聚和分裂的过程中,伴随着强烈的磨圆作用。During the freeze-thaw cycles leading to particle fragmentation and aggregation,the size and mor⁃phology of particles will be significantly changed.In order to study the influence of freeze-thaw cycles on parti⁃cle size and morphology,the Qinghai-Xizang silt was selected for 0,1,5,10,50 and 100 free freeze-thaw cy⁃cles under closed system.After the particle size composition was tested by the liquid transfer tube method,the PIP9.1 particle image processor was used to collect the shape parameters such as particle aspect ratio and round⁃ness.The experimental results are as follows:The freeze-thaw action caused the angular edges of the particles to be broken,and the mass percentage of particles with particle size less than 0.001 mm increased.The particle as⁃pect ratios were mainly distributed between 1 and 3,accounting for more than 94%,and the semi-logarithmic histogram of the aspect ratios conformed to the normal distribution.Roundness was distributed between 0.09~1,and the average roundness of the particles increased after 100 freeze-thaw cycles.After 100 freeze-thaw cycles,the particle aspect ratio and particle size decrease,the roundness increases,and the particle shape tends to be round.It is found that during the freezing and thawing process,the Qinghai-Xizang silt particles are fragmented and aggregated,accompanied by a strong rounding effect.

关 键 词：冻融循环 颗粒尺寸 颗粒形态 长径比 圆度 青藏粉土 

分 类 号：P642.14[天文地球—工程地质学]