粗粒含量对红砂岩粗粒土压实变形特征的影响

Impact of Coarse Grain Content on Static Compaction Deformation Characteristics of Red Sandstone Soil

为研究粗粒含量对红砂岩土静力压实变形特征的影响,利用自制装置在电子万能试验机上进行静力压实试验,得到6种不同粗粒含量红砂岩土静力压实试验的压力-位移关系,分析粗粒含量对静力压实变形特征的影响。结果表明:不同粗粒含量红砂岩土在静力压实过程中的应力与应变符合指数关系;在相同的应力作用下,当粗粒含量为60%时,土体产生的应变最大;不同粗粒含量红砂岩土的压缩模量与对应应力范围终值之间呈线性关系,在相同应力范围内,当粗粒含量为60%时土体的压缩模量最小,压缩性最高;红砂岩粗粒土的静力压实过程可分为3个阶段,分别为压密阶段、破碎阶段和稳定阶段;在静力压实过程中,应变增长存在拐点;应变拐点的出现,标志着红砂岩粗粒土静力压实过程变形阶段的转变。

To study the static compaction deformation characteristics of different coarse grain content red sandstone soil, static load compaction tests are conducted by using electronic universal testing machine. Compression force - displacement relations of red sandstone filling are obtained and the effects of coarse grain content on static compaction deformation characteristics are analyzed. The results show that in the compaction test of red sandstone filling, relationship between the stress and displacement is exponential; under the same stress when the coarse grain content is 60%, the strain of soil mass is the largest; with different coarse grain content, the compression modulus of red sandstone has a linear relation with the ultimate value of its corresponding stress scope, and with the same stress range, when the coarse grain content is 60%, the soil mass has the minimum compression modulus and highest compressibility; the static compaction process can be divided into three stages：compaction stage, broken stage and stable stage. In the process of static compaction, strain growth exist a turning point; when the turning point indicates that the compaction stage shifts to broken stage.