Study on the displacement and stress variation of frozen curtain during excavation of subway cross passage

Abstract

Understanding the deformation behavior of the frozen curtain during excavation is crucial when employing artificial freezing methods in construction. This study uses indoor frozen soil experiments and numerical simulations to determine the compressive and flexural strengths of the frozen curtain, along with its displacement and stress variation patterns. Results show that lower freezing temperatures continuously increase uniaxial compressive strength, flexural strength, and elastic modulus of frozen soil, while Poisson's ratio decreases. Among the two soil types studied, silty interlayered with sand demonstrates greater compressive strength, flexural strength, and elastic modulus. Numerical simulation analysis indicates that the top of the frozen curtain experiences settlement during cross passage excavation, while the bottom exhibits uplift. The safety factors of the frozen curtain were validated and confirmed to be within safe limits. This study integrates frozen soil experiments and numerical simulations to offer guidance for future cross passage excavations and related engineering designs.