摘要
黄土体长期处于降雨和蒸发的湿热耦合环境,极易诱发土体裂隙产生,显著弱化土体的结构性和完整性,从而影响工程区域的建设。因此,对干湿循环作用下不同厚度的黄土开裂特性研究十分必要。该文通过室内干湿循环试验,记录试样的含水率变化和裂隙发育情况,利用数字图像处理技术,结合分形维数对裂隙网络进行分析。试验结果表明,蒸发路径和含水量的不同导致土体水分蒸发速度不同,土体越厚,水分蒸发速度越慢。界面摩擦力影响土体开裂过程,土体越厚,裂隙发育越慢,裂纹网络复杂性越低。随着干化的进行,界面摩擦力逐渐降低,土体收缩明显,干湿循环效应导致土体颗粒重新组合,加快水分蒸发过程,土体表面会不断劣化。研究结果可为地质灾害防治提供指导。
The loess with different thickness is in the humid-thermal coupling environment of rainfall-evaporation for a long period of time,which is very prone to induce the generation of cracks in the loess,significantly weakening the structural and integrity of the loess,thus affecting the construction of the project area.Therefore,it is necessary to study the effect of soil thickness on the cracking characteristics of loess under the action of wet dry cycles.In this paper,a series of indoor wet dry cycle tests were carried out to record the water content change and crack development of the specimens in real time,and the crack network was analyzed by using digital image processing technology combined with fractal dimension.The test results show that:the different evaporation paths and water contents lead to inconsistent water evaporation rate of the soil,and the greater the thickness of the loess,the slower its water evaporation rate;interfacial friction affects the cracking process of the soil,and the thicker the soil,the slower the development of cracks,and the lower the complexity of the crack network.As drying proceeds,the interfacial friction gradually decreases and the soil shrinks significantly.The dry-wet cycle effect will lead to the reassembly of soil particles,accelerate the water evaporation process,and the soil surface will deteriorate continuously.The results of the study can provide some guidance for the prevention and control of geologic hazards in the Loess Plateau region.
作者
焦少通
王家鼎
张登飞
戚利荣
李帅
李琳
李珊
JIAO Shaotong;WANG Jiading;ZHANG Dengfei;QI Lirong;LI Shuai;LI Lin;LI Shan(State Key Laboratory of Continental Dynamics,Department of Geology,Northwest University,Xi’an 710069,China)
出处
《西北大学学报（自然科学版）》
CAS
CSCD
北大核心
2024年第1期1-10,共10页
Journal of Northwest University（Natural Science Edition）
基金
国家自然科学基金重大科研仪器研制项目(42027806)
国家自然科学基金重点项目(41630639)
西北大学研究生创新项目(CX2023012)。
关键词
干湿循环
土体厚度
裂隙特征
分形维数
摩擦力
dry-wet cycles
soil thickness
fracture characteristics
fractal dimension
friction
