Abstract:With the increasing demand for global connectivity, research on superlong-span bridges has received increasing attention. This study revealed that the absence of internal forces and infinite structural stiffness are the basic conditions for building bridges with infinite spans. Based on this, three types of superlong-span collaborative bridge systems were built using the bridge type quadrant diagram and the characteristics of superlong-span bridges and specific measures to improve bridge stiffness were summarized. The bridge type quadrant diagram provides not only a simple approach for building structurally complex collaborative bridge systems but also a method for building superlong-span bridges. The results show the existence of three collaborative system bridges: the stayed cable-umbrella truss collaborative system bridge, the suspension-arch collaborative system bridge, and the stayed cable-suspension-arch-umbrella truss collaborative system bridge. Those collaborative system bridges meet the conditions of relatively ideal bridges and have the potential to become superlong-span bridges. The symmetry and force transmission paths of the bridge quadrant diagram reveal the construction characteristics of superlong-span bridges.