透明土与标准砂压缩变形特性对比试验研究

人工合成透明土模拟天然土体,以研究土体内部位移场和渗透场等问题的可视化模型试验方法逐渐得到相关工程技术人员的认可与应用;然而,针对不同类型人工合成透明土的压缩变形特性的研究却相对较少。基于熔融石英砂和无定形二氧化硅这两种固体颗粒材料,开展不同孔隙液体、粒径范围及相对密实度等情况下的单向压缩试验;分析不同制配方法和制配材料所制配成的透明土材料的压缩变形特性,并与福建标准砂、Toyoura砂的单向压缩试验进行对比分析。同时,针对典型透明土土体在载荷板作用下的土体内部位移场进行了简要对比分析。试验结果表明,本文试验条件下,由蔗糖溶液制配的熔融石英砂透明土压缩性相对于由混合油及溴化钙溶液制配的压缩性更接近天然砂土;熔融石英砂相对于无定型二氧化硅更适合模拟天然砂土;与福建标准砂相比,透明土材料的压缩性相对较大,且目前模型试验中常用的0.5~1.0 mm粒径制配成的透明土压缩性相对更大,值得相关研究人员重视。

Comparative experiments on compressive deformation properties of transparent soil and standard sand

Visualization model tests on internal soil deformation and flow problems by using transparent soil to replace natural soil are gradually recognized and applied. However, the researches focusing on compressive deformation properties of transparent soil manufactured by different methods are relatively little. Based on the two granular materials of fused quartz and silica gel, one-dimensional compression tests on transparent soil manufactured with different pore fluids, particle size distributions and relative densities are carried out. The test results on Fujian standard sand and Toyoura sand are comparatively analyzed and discussed. At the same time, the internal displacement fields of typical transparent soil under the effect of loading plate are comparatively analyzed. The results show that the compressibility of transparent soil manufactured with sucrose solution pore fluid is relatively closer to that of natural sand than those manufactured with mixed oil and calcium bromide solution pore fluid. The baked quartz is more capable of modeling natural sand than the amorphous silica gel. The compressibility of transparent soil is larger than that of Fujian standard sand, especially the transparent soil manufactured with particle size of 0.5~1.0 mm, which more attention should be paid to.