王秋生,苏瑞林,高晓静.重塑黏性土及不同砂砾含量土体的起动试验研究[J].水利学报,2018,49(8):975-985 |
重塑黏性土及不同砂砾含量土体的起动试验研究 |
Experimental study on incipient motion of remolded cohesive soils and cohesive/non-cohesive mixtures |
投稿时间:2018-03-01 |
DOI:10.13243/j.cnki.slxb.20180183 |
中文关键词: 冲刷 黏性土 重塑土 混合土体 起动应力 |
英文关键词: scour cohesive soil remolded soil mixture critical shear stress |
基金项目:国家自然科学基金项目(51679003,50779073) |
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中文摘要: |
应用冲蚀函数测定仪开展了两种重塑黏土及其砂砾含量分别为20%、40%、60%条件下的起动试验,研究了黏聚力、干密度、砂砾粒径及掺量对土体起动应力的影响。试验结果表明:纯黏性土的起动应力与黏聚力呈线性关系,但两种黏土的斜率变化较大;两种黏性土的起动应力与干密度的关系可统一用指数型表达式确定;不同砂砾含量土体的起动应力与黏性土的黏聚力、砂砾粒径和掺量有关;砂砾粒径一定时,随着掺砂砾量的增加,混合体的起动应力呈先增加后降低的趋势,而砂砾含量一定时,起动应力随着砂砾粒径的增加而增加。最后,提出了重塑黏性土-砂砾混合土体的起动应力表达式。与试验结果的对照表明,该公式可较好地对黏性土-砂砾混合体的起动应力进行预测。 |
英文摘要: |
The erosion resistance of two kinds of remolded pure cohesive soils as well as cohesive/non-cohesive mixtures with 20%,40%,60% non-cohesive fraction respectively was tested in Erosion Function Apparatus. The influences of cohesion,dry density,non-cohesive soil particle size and mass content on the critical shear stress of soils were investigated. The results obtained show that the critical shear stress of pure cohesive soils has a linear relation to cohesion, but for different kinds of cohesive soils the coefficients are much different. Compared to cohesion, the relationship between dry density of 2 pure cohesive soils and critical shear stress can be determined by an exponential function. For mixtures, the critical shear stress is mainly related to cohesion, however, non-cohesive soil particle size and mass content can affect critical shear stress as well. When the particle size of non-cohesive soil is determined, with the increase of non-cohesive soil content, the threshold exhibits an increase at first and then a decrease. Nevertheless, as non-cohesive soil content is constant,with the increase of non-cohesive soil particle size,the threshold increases. A critical shear stress model of remolded soils is proposed, which can provide a proper prediction of critical shear stress of cohesive/non-cohesive mixtures. |
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