透明黏土可视度及物理力学特性研究
Visibility and mechanical properties of transparent clay
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摘要: 透明土是用于岩土工程模型试验可视化研究的一种重要材料,明确其可视度控制因素与物理力学特性具有重要的意义。采用#15白油与正十二烷作为孔隙液体,无定形硅粉作为固相材料,通过对比不同的孔隙液体配比和掺入硅粉的质量比,发现可视度达到最佳时的配比为15号白油∶正十二烷=10∶3(体积比),孔隙液体∶无定形硅粉=1.5∶1(质量比)。针对最佳可视度的透明黏土进行了变形与强度特性试验,试验结果表明透明黏土属于高压缩性土,并且与天津滨海软黏土的压缩变形特征相近,二者压缩系数和压缩模量相差在10%以内;固结快剪试验表明当透明黏土的当应力水平较低(不大于200 kPa)时,透明黏土的抗剪强度指标可以取c≈11 kPa,φ=14°~18°,当应力水平较高(大于200 kPa)时,可以取c=20.28~22.62 kPa,φ≈17°。Abstract: The transparent soil is a kind of important material for the visualization researches model tests in geotechnical engineering. It is of great significance to clarify its visibility control factors and physical and mechanical properties. The white oil No. 15 and n-dodecane are used as the pore liquid, and the amorphous silicon powder is used as the solid phase material. By comparing the ratio of different pore liquids and the mass ratio of silicon powder, it is found that the visibility is the best when the ratio of the white oil No. 15 to the n-dodecane is 10:3 (volume ratio) and that of the pore liquid to the amorphous silicon powder is 1.5:1 (mass ratio). The deformation and strength characteristics of the transparent clay with the best visibility are tested. The test results show that the transparent clay is a highly compressive soil, and its compression deformation characteristics are similar to those of Tianjin coastal soft clay, and their differences in compression coefficient and compression modulus are within 10%. The consolidated quick shear tests show that when the stress level of transparent clay is relatively lower (≤200 kPa), the strength indices can be taken as c≈11 kPa, φ=14°~18°, and when the stress level is relatively higher (>200 kPa), the strength indices can be taken as c=20.28 kPa~22.62 kPa, φ≈17°.