玻璃砂透明土变形特性三轴试验研究

Triaxial tests on deformation characteristics of transparent glass sand

玻璃砂透明土是一种由玻璃砂、正十二烷和15号白油按质量比1∶4的混合液体制备而成的新型人工合成透明土;该材料具有透明度高,与天然土体相似度更好等优点,可以用于基于透明土材料的可视化模型试验。为了研究其变形特性,对不同级配的玻璃砂透明土,进行三轴固结不排水剪切试验和三轴固结排水剪切试验,并与同等条件下的福建标准砂试验结果进行对比分析;测得固结不排水剪应力-应变曲线、以及孔压应变曲线形态等工程特性。试验结果表明,随着相对密度的增加,玻璃砂的应力-应变关系从应变硬化型向应变软化型过渡,破坏时的孔压系数Af降低,变形模量变大;与标准砂相比,玻璃砂透明土的应力-应变曲线峰值来的相对更慢一些。

Based on the transparent soil materials and digital imaging technology, the model tests on geotextile can be visualized. Transparent glass sand is one kind of new transparent synthetic soil materials, which is composed by glass sand, twelve alkane and white mineral oil mixture （1 ：4）. This new material has good transparency, and its properties are similar to those of natural soil. Hence, it can be used in visualization model test technique. Based on the consolidated undrained triaxial compression tests and consolidated drained triaxial compression tests, the deformation properties of the transparent glass sand with different size ranges are studied. For comparative analysis, the deformation properties of standard sand are also obtained. Then stress-strain curves and pore pressure-strain curves of the soil are measured. The laboratory test results show that the stress-strain relation is transited from strain hardening to strain softening, and the pore pressure coefficient and deformation modulus decrease with the increase of the relative density. The peak of the stress-strain curve of the transparent glass sand is relatively slower compared with that of the standard sand.