利用人工合成透明土的岩土物理模拟试验

结合粒子图像测速（PIV）和近景摄影技术，建立了一种利用人工合成透明土的岩土物理模拟试验方法，非侵入观测和记录了浅基础沉降（SFS）引起的土体变形，并与利用天然土的传统模型试验进行了对比研究。透明土是由与熔融石英的折射率相匹配的孔隙溶液组成。采用激光面照射透明土模型并拍摄下SFS引起变形的数字图像，利用基于MATLAB的Geo-PIV软件获得了所产生的位移场。试验结果对比分析显示：与天然砂土中的相比，在透明土中SFS引起的扰动区域较大，最大剪应变扩大了约1.5倍，表层隆起范围约增加了30～50%；然而透明土中土体单元的运动趋势总体上与天然砂土中的相似，表明所建立的试验方法在机制研究上具有一定程度的适用性。

Geotechnical physical model test using artificial synthetic transparent soil

By combining the technologies of particle image velocimetry (PIV) and close-range photogrammetry, a procedure for geotechnical physical modelling using artificial synthetic transparent soil is developed. The soil deformation caused by the shallow foundation settlement (SFS) are measured and recorded non-intrusively. The conventional model test using natural soils is employed for the purpose of comparison. The transparent soil is made of a pore solution, the refractive index of which is matched with the refractive index of fused quartz. Transparent soil model is sliced by using a laser light sheet and digital images of soil deformations caused by SFS are captured. The MATLAB-based software, Geo-PIV, is employed to obtain the generated displacement fields. The results show that the SFS-induced disturbance zone is enlarged in transparent soil, the maximum shear strain expands by about 1.5 times, and the range of surface heaving increases by 30-50% in transparent soil compared with those in natural soil; however, the movement trends of soil elements in transparent soils are generally similar to those in natural soils, indicating that the proposed modelling methodology has applicability to mechanism study to some extent.