Full-Scale Testing and Stability Analysis of Prefabricated Steel Plate-Concrete Composite Walls in Underground Granaries

Underground granaries naturally preserve grain quality by maintaining low temperatures and reduced oxygen levels, eliminating the need for artificial cooling and pest control. However, cast-in-place reinforced concrete construction faces challenges such as waterproofing and complex on-site processes, necessitating prefabricated steel plate-concrete composite structures with robust joints for enhanced structural integrity and streamlined construction. The study utilizes a full-scale prefabricated steel plate-concrete underground silo, instrumented with strain gauges on circumferential steel bars and internal steel plates to monitor stress variations during six distinct backfilling loading cases. Concurrently, finite element models were developed using ABAQUS 6.14 software for numerical simulations, which were validated against experimental data. Stability analyses, including buckling load assessments and parameter sensitivity studies, were conducted to evaluate the effects of joint quantity and bending stiffness on the structural performance of the composite walls. The results revealed that circumferential joints play a critical role in stress distribution within the composite walls, underscoring the necessity of optimized joint design. The numerical model accurately replicated experimental results, with deviations below 9%, confirming its reliability. Furthermore, an equivalent joint design method was established, demonstrating that a joint bending stiffness ratio above 1.1 ensures that prefabricated composite walls achieve critical buckling loads comparable to cast-in-place walls. These findings provide a robust framework for enhancing the structural performance and reliability of prefabricated underground silos.