How Does Large-Span GRC Shaping Ensure Structural Stability? Integrated Mechanical Design and Coordinated Working System

The structural stability of large-span GRC features (such as unsupported cornices exceeding 6 meters or large arched components) is by no means achieved simply by increasing thickness; it is a comprehensive subject involving material strength, the support system, connection nodes, and load analysis. When Qinglong Group undertook a GRC wave-shaped cornice with a span of 8 meters for a terminal building at an airport in Xiamen, it adopted a systematic solution of "internal prestressed reinforcement + coordinated load-bearing with external steel keels + refined finite element analysis," ensuring absolute safety under typhoon loads.

First is the reinforcement design of the GRC component itself. For large-span components, we typically employ "prestressing technology." During component production, unbonded prestressed steel strands or GFRP bars are embedded, and tensioning is carried out once the GRC reaches the specified strength. This is equivalent to pre-applying a reverse bending moment inside the component, which can significantly counteract the tensile stress generated by external loads and improve crack resistance and stiffness. Meanwhile, the component's cross-section is designed as an efficient section form such as an I-shape or box shape, rather than a solid flat slab, to obtain the maximum sectional moment of inertia with the minimum amount of material. The internal steel mesh is also differentially configured according to the bending moment envelope diagram, with denser placement at the supports and mid-span.

The external support and connection system provides another layer of safety assurance. Large-span GRC components often need to form a composite load-bearing system together with concealed steel keels. Through precise calculation, we determine the specifications and spacing of the primary and secondary keels, designing them as spatial trusses or frames. The connection between GRC panels and keels follows the principle of "multi-point positioning with flexible release": rigid connection points (such as seismic steel clamps) are set in high-stress areas, while sliding supports that allow for thermal deformation are used elsewhere. All connection nodes undergo detailed finite element analysis to ensure the stress concentration factor remains within a safe range.

Full-process load analysis and simulation form the foundation of the design. In addition to conventional gravity, wind, and seismic loads, large-span features also require special consideration of "nonlinear effects," such as second-order effects caused by large geometric deformations and stresses induced by temperature gradients. We use software such as ANSYS or ABAQUS to perform nonlinear finite element analysis, simulating the stress state of components throughout the entire process from installation to service. For projects exceeding standard limits, wind tunnel tests or shaking table tests must also be conducted to obtain accurate load data. During the construction phase, we employ BIM technology for virtual pre-assembly and hoisting simulation, and implement strict deformation monitoring to ensure installation accuracy is consistent with the design model. It is precisely through the comprehensive application of this multi-level, multi-line-of-defense, and refined design philosophy that those seemingly light, deeply cantilevered large-span GRC features can stably withstand the forces of nature and achieve breathtaking architectural artistry.