Conceptual design of long span steel-UHPC composite network arch bridge

•An innovative composite network arch bridge with a main span of 470 m is proposed.•A novel arch rib with a UHPC outer layer and an inner steel tube is developed.•Topology optimization is used to design the arch hinges and the wind bracing.•The bridge configuration is optimized through parametric analyses.•The proposed bridge exhibits superior structural performance and other advantages.