As an innovative technology, transparent soil similar material can actively promote the development of soil model experiments by clarifying the structure, ratio, and strength characteristics. In order to study the factors affecting the mechanical properties of transparent soil materials, fused quartz is chosen as the aggregate material, nano-scale hydrophobic fumed silica is used as the binder, and a mixture of dodecane and No. 15 white oil is employed as the constituent material for transparent soils. In this study, indoor direct shear tests are conducted, and the range method is used to analyze the factors of quartz particle size, binder content and proportion, moisture content and dry density of the mixture solution. The relationship between the strength properties of transparent soil material and the above variables are quantitatively investigated. The results show that the transparent soil similar material can exhibit softening or hardening properties by changing the proportion of influencing factors, which can be suitable to most soils. Dry density has the most significant impact on cohesion while particle size of quartz has the greatest influence on the internal friction angle. The strength parameter of transparent soil has exponential distribution relationship with moisture content and linear distribution relationship with dry density. The cohesion and powder content are distributed exponentially while the internal friction angle and powder content are linearly distributed. As the particle size of quartz increases, the cohesion decreases overall and the internal friction angle increases. The strength parameters of transparent soil have a logarithmic distribution relationship with the unevenness coefficient of particle size and a linear relationship with the curvature coefficient of particle size. This study has established a quantitative control relationship between the key parameters of transparent soil materials and their mechanical properties. The revealed correlations between gradation of particles and strength parameters can serve as a guideline for simulation and visualization techniques based on transparent soils. It is of great significance for the visualization of the evolution mechanisms of geotechnical disasters.

To broaden the sources of subgrade filler and the utilization of Soda Residue (SR), SR was employed to modify clay by adding a small amount of lime for further stabilization, forming a Lime-Soda-Residue-Stabilized Soil (LSRSS). A set of intensive research paths was established, from testing of laboratory mechanical property, mechanism disclosure, and field verification to operational effect. Through Unconfined Compressive Strength (UCS), California Bearing Ratio (CBR), and Resilient Modulus (MR) experiments, it was concluded that with the increase in SR content, the UCS, CBR, and MR values of LSRSS showed an increasing trend then followed by a decrease, reaching their peak values, respectively of 0.62 MPa, 65.0%, 78.83 MPa, all at 30% SR content. An optimal proportion was determined for LSRSS as 6% lime, 30% SR, and 70% clay. The UCS, CBR, and MR values of optimal proportion all increased with the increase of compaction degree, but increased first and then decreased with the increase of water content. Their maximum values did not correspond to the OWC of 23% but to 27%, called the compaction water content, which was suitable for application in the actual LSRSS subgrade. Field test results showed that the UCS, CBR, and MR values were 0.85 MPa, 86.5%, and 135.7 MPa, which all were higher than the laboratory values, and the long-term road performance was outstanding. The analysis demonstrates that the better strength and road performance of LSRSS are mainly determined by the superior gradation and the reaction of three materials. The laboratory and field test results collectively provide data evidence for excellent performance and lay a solid foundation for the wider application of the LSRSS subgrade.