Abstract: In order to strengthen the design and construction quality control of mudstone slope, annular knife samples with different initial water content and compaction degree are prepared with expansive mudstone weathered soil samples from northwest Hebei Province as raw materials, and micro-deformation expansion force tests with deformation values of 0,0.2, 0.4 and 0.6 mm are carried out by using a single lever consolidation instrument. The law between swelling force and two factors of compaction degree and initial moisture content is studied, the mechanism of swelling force change under micro-deformation is analyzed, and the correlation between each factor and soil swelling force is analyzed by grey correlation theory. The results show that under “0” deformation, the time history curve of the expansion force can be divided into three stages: rapid growth of the expansion force, slow growth of the expansion force and stable expansion force. Under micro-deformation, the time history curve of the expansion force can be divided into two stages: slow growth of the expansion force and stable expansion force. Under the condition of a certain degree of compaction, the expansion force decreases with the increase of initial water content. Under the condition of a certain water content, the expansion force increases with the increase of the degree of compaction. The expansion force P_e can be reduced effectively by increasing the allowable micro-deformation rate. According to the calculation results of grey correlation theory, it is found that the effect of allowable micro-deformation rate on the swelling force of mudstone samples is the most sensitive factor compared with initial water content and compaction degree.

Key words: expansive mudstone, expansive force, micro-deformation, allowable micro-deformation rate, grey correlation theory

摘要： 为加强泥岩边坡的设计和施工质量控制,以冀西北地区膨胀性泥岩风化土样为原材料,制备不同初始含水率、压实度的环刀试件,利用单杠杆固结仪开展了变形量分别为0、0.2、0.4和0.6mm的微变形膨胀力试验,研究了膨胀力与压实度、初始含水率双因素之间的规律,分析微变形条件下膨胀力变化机制,并采用灰色关联理论对各因素与土体膨胀力之间进行相关性分析。研究结果表明:“0”变形下,膨胀力时程曲线划分为膨胀力急剧增长、膨胀力缓慢增长、膨胀力稳定3个阶段;而在微变形下,膨胀力时程曲线划分为膨胀力缓慢增长、膨胀力稳定2个阶段;在压实度一定的条件下,膨胀力随初始含水率的增大而减小;在含水率一定的条件下,膨胀力随压实度的增大而增大;提高允许微变形率Δ能够有效地减小膨胀力P_e;根据灰色关联理论计算结果,发现允许微变形率较初始含水率、压实度对泥岩试样膨胀力的影响最为敏感。

关键词: 膨胀性泥岩, 膨胀力, 微变形, 允许微变形率, 灰色关联理论