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

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