土-石混合体土-水特性和微观结构的相关性研究

Correlation between soil-water characteristics and microstructure of soil-rock mixture

为探究秦巴山区土−石混合体土−水特性和微观结构的相关性,分别对不同孔隙比、含石量的土−石混合体开展非饱和入渗试验和压汞试验。试验结果表明:高压实度、低含石量下土−石混合体土−水特性曲线明显高于低压实度、高含石量土−水特性曲线;影响土−石混合体土−水特性的孔隙孔径在小于200μm范围内;含石量较低时,提高压实度造成孔隙向低孔径范围集中,使得土−水特性曲线在该孔径范围变陡;含石量较高时,提高压实度主要压缩大孔径孔隙(d>80μm),对小孔径孔隙的影响较小,使其土−水特性曲线较为一致。密实度较高时,增加含石量造成土−石混合体的孔隙分布更为均匀,土−水特性曲线由陡峭变为平缓;当密实度较低时,不同含石量下其小孔隙部分结构差异较小,土−水特性曲线较为一致。

In order to explore the correlation between soil-water characteristics and microstructure of soil-rock mixtures in Qinling Bashan Mountains,unsaturated infiltration test and mercury intrusion test were carried out on soil-rock mixtures with different void ratios and rock contents.The test results show that the soil-water characteristic curve of soil-rock mixture under high compaction and low rock content is obviously higher than that under low compaction and high rock content.The pore size which affects the soil-water characteristics of soil-rock mixtures is within the range of less than 200μm.For the soil-rock mixture sample with low rock content,increasing the compaction degree will cause the pores to concentrate in the range of small pore size,thereby making the soil-water characteristic curve steeper in this pore size range.For the sample with high rock content,increasing the compaction degree mainly compresses the large pore(d>80μm),which has almost no effect on small pores,resulting in the consistency of soil water characteristic curve within the research scope.When the compactness is high,increasing the rock content causes the pore size distribution of the soil-rock mixture to be more uniform,and the soil-water characteristic curve changes from steep to gentle.For the soil-rock mixture with low compactness,the structure of small pores under different rock content conditions has little difference,which makes the soil water characteristic curve from different samples relatively consistent.