摘要
为了明确增湿-减湿作用下重塑黄土的宏观变形特性及微观结构特性,以陕北某填方区黄土为研究对象,利用单杠杆固结仪和扫描电子显微镜对增湿-减湿条件下重塑土体的宏观力学性能和微观结构变化进行分析。研究结果表明:宏观方面,侧向压缩应变与增湿-减湿循环次数正相关,并且增湿-减湿循环下侧限压缩应变规律可以用幂函数表示,说明长期的水土相互作用使压实土体强度及承载力降低;微观方面,增湿-减湿循环使压实黄土孔隙结构增大、颗粒形态由扁平状变成圆形以及颗粒接触方式由面-面接触变为点-点接触,导致土体结构松散产生裂缝,颗粒间摩擦力及承载力降低。通过对重塑黄土的宏微观分析,为黄土区域的建设工程提供理论依据。
In order to clarify the macroscopic deformation characteristics and microscopic structural characteristics of the remolded loess under humidification-dehumidification,the loess in a filling area in northern Shaanxi was taken as the research object,and the conditions of humidification-dehumidification were measured by a single lever consolidation instrument and scanning electron microscope.The macroscopic mechanical properties and microscopic structural changes change of the remolded soil were analyzed.The research results show that in the macroscopic aspect,the lateral compressive strain is positively related to the number of humidification-dehumidification cycles,and the law of the lower limit compressive strain of the humidification-dehumidification cycle can be expressed by a power function,indicating that long-term water-soil interaction causes compaction soil strength and bearing capacity decrease.Microscopically,the humidification-dehumidification cycle increases the pore structure of the compacted loess,changes the particle shape from flat to round,and the particle contact mode changes from surface-to-surface contact to point-to-point contact,resulting in loose soil structure cracks,and reduced friction between particles and bearing capacity.The macroscopic and microscopic analysis of the remol-ded loess provides a theoretical basis for the construction of loess regions.
作者
叶万军
强艳红
张文
吴云涛
陈义乾
YE Wan-jun;QIANG Yan-hong;ZHANG Wen;WU Yun-tao;CHEN Yi-qian(College of Architecture and Civil Engineering,Xi'an University of Science and Technology,Xi'an 710054,China;College of Architecture and Civil Engineering,Chang'an University,Xi'an 710064,China)
出处
《科学技术与工程》
北大核心
2020年第29期12058-12064,共7页
Science Technology and Engineering
基金
国家重点研发计划(2018YFC0808705)
国家自然科学基金(41672305,41902299)
陕西省重点研发计划(2017zdxm-sf-078)。
关键词
黄土
增湿-减湿
侧限压缩应变
微观结构
loess
humidification-dehumidification
confined compression strain
microstructure
