In modern construction projects, a significant challenge arises from the consequential impacts of developing adjacent structures. The interplay of stresses within neighboring foundations can lead to a range of issues, such as deformation, leaning, cracking, instability, and various other damages. Among the numerous factors affecting foundation interaction, this research uniquely focuses on the impact of soil type, utilizing precise physical modeling through a 1 g testing apparatus. To enhance measurement accuracy, image processing techniques are employed in conjunction with LVDT and displacement gauges. The study systematically investigated the roles of five distinct deposit types -soft clay, loose sand, silty sand, loess, and low-compacted Tehran clay -in the manifestation of settlement and tilt arising from foundation adjacency. Subsequent to this evaluation, a comprehensive examination of strategic measures aimed at preventing and mitigating damages resulting from foundation interaction is undertaken. For silty sand, a detailed comparison of five remediation techniques is conducted, while in other soil types, only densification method is applied to address settlement and tilt. The comparison is based on the reduction in settlement and tilt, after the implementation of remediation methods under new foundation. Results highlight the crucial role of soil properties in determining damages from foundation adjacency. Notably, Tehran soil with low density exhibits maximum settlement in its loose state, while loess soil shows the highest settlement in the dense state. The exploration of soil improvement methods reveals that diaphragm walls and pile groups are influential in minimizing tilt and settlement of existing foundations, while pile groups proved to be the best remediation method in controlling displacements of new foundation.

The warm and ice-rich frozen soil is characterized by high unfrozen water content, low shear strength and large compressibility, which is unreliable to meet the stability requirements of engineering infrastructures and foundations in permafrost regions. In this study, a novel approach for stabilizing the warm and ice-rich frozen soil with sulphoaluminate cement was proposed based on chemical stabilization. The mechanical behaviors of the stabilized soil, such as strength and stress-strain relationship, were investigated through a series of triaxial compression tests conducted at -1.0 degrees C, and the mechanism of strength variations of the stabilized soil was also explained based on scanning electron microscope test. The investigations indicated that the strength of stabilized soil to resist failure has been improved, and the linear Mohr-Coulomb criteria can accurately reflect the shear strength of stabilized soil under various applied confining pressure. The increase in both curing age and cement mixing ratio were favorable to the growth of cohesion and internal friction angle. More importantly, the strength improvement mechanism of the stabilized soil is attributed to the formation of structural skeleton and the generation of cementitious hydration products within itself. Therefore, the investigations conducted in this study provide valuable references for chemical stabilization of warm and ice-rich frozen ground, thereby providing a basis for in-situ ground improvement for reinforcing warm and ice-rich permafrost foundations by soil-cement column installation.