A novel interfaces contact model for analyzing assembled joints of prefabricated underground structures

Modern prefabricated underground structures are the key advancement in the low-carbon urban construction. The rapid development of prefabricated structures has increased the diversity of assembled joints. It becomes more difficult to evaluate the joint performance considering multiple parameters, such as joint size, morphology, interface properties, and axial forces. Therefore, this study developed an assembled joints mechanical assessment model to solve the multi-parameter problems. First, the interface contact formulas were established for typical interfaces. Second, a joint interfaces contact model (JICM) was established based on the above formulas and multiple parameters. Finally, model validation and case study were performed for JICM. The results show that: (1) JICM fitted well with the experimental data, and reflected the multi-parameter effects of multi-type assembled joints. (2) JICM calculated the contact stress at the outer edge of the interfaces can be twice larger than the bending stress. Accordingly, JICM revealed the key reason for brittle damage of assembled joints. (3) JICM demonstrated promising joint design capabilities: it calculated that the bending moment contribution of one interfaces group was dominant; it further calculated the deformation and bearing capacity of the assembled joints at the yield and ultimate moments. (4) JICM demonstrated promising joint deformation control: it calculated the rotation developments of assembled joint and continuous section were not consistent; it further presented the deformation pattern of the assembled components was a folded line and can be 20% larger than that of a continuous component. JICM provides a tool for parametric design of joints and quantitatively evaluates multi-parameter effects, demonstrating practical value for urban green low-carbon construction.

Automated summary

This study developed an assembled joints mechanical assessment model to solve the multi-parameter problems of assembled joints. The model fitted well with the experimental data and demonstrated the potential for joint design and deformation control, providing practical value for urban green low-carbon construction.