Concrete-Filled Cavity Joints Boost Load Capacity of Prefabricated Underground Silos

Prefabricated steel plate-concrete composite underground silos promise faster construction, lower costs, and better waterproofing than conventional reinforced concrete silos, but their joints remain the weakest links in the assembled structure. Researchers have now proposed and tested two novel prefabricated joint designs for these silos: a steel cavity joint and a concrete-filled cavity joint. Full-scale axial compression tests and nonlinear finite element simulations in ABAQUS reveal how each configuration carries load, deforms, yields, and ultimately fails, offering a basis for choosing between them in practice.

The full-scale axial compression tests evaluated the load-bearing capacity, deformation behavior, yielding, and failure modes of specimens built with each joint type. The specimen with the steel cavity joint failed primarily through instability of the external waterproof steel plate under axial compression. During the elastic stage, that steel plate contributed approximately 41 percent of the applied load. In contrast, the specimen with the concrete-filled cavity joint failed by crushing of the prefabricated concrete blocks, and the concrete inside the cavity carried roughly 75 percent of the applied load during the elastic stage, shifting the load path from a thin steel plate to a stiffer concrete core.

The numerical simulations, performed with nonlinear finite element analysis in ABAQUS, further clarified the load-transfer mechanisms within both joint configurations. Together with the experimental results, the modeling showed that filling the cavity with concrete changes the joint’s structural response substantially. Compared with the steel cavity joint, the concrete-filled cavity joint exhibited significantly improved initial stiffness and achieved an increase of more than 28 percent in peak load capacity, making it the stronger of the two configurations under axial compression.

The study also examined how key joint parameters affect axial compressive performance, providing designers with levers to tune the joints for specific projects. One practical finding concerns material efficiency: the strength grade of the concrete placed in the cavity can be appropriately reduced without compromising the joint’s function, which optimizes material utilization. Because joints are critical weak components in prefabricated structures, the development of simple and efficient joint configurations is described as essential for the further advancement and application of novel prefabricated underground silos, where cost, construction duration, and waterproofing are the key challenges that conventional reinforced concrete designs struggle to meet.

Subject of Research: Prefabricated joint designs for underground silos tested under axial compression

Article Title: Novel prefabricated joints for underground silos with steel cavity and concrete-filled cavity: Axial compression tests and numerical simulations

Article References: Li, J., & Chuai, J. (2026). Novel prefabricated joints for underground silos with steel cavity and concrete-filled cavity: Axial compression tests and numerical simulations. PLOS One, 21(10), e0361019. https://doi.org/10.1371/journal.pone.0361019

Image Credits: AI Generated

DOI: 10.1371/journal.pone.0361019

Keywords: prefabricated structures, underground silos, steel plate-concrete composite, axial compression tests, finite element analysis, ABAQUS, joint design, structural engineering, load-bearing capacity, construction technology, Novel, prefabricated