Performance improvement method of bridge by the application of UHPC waffle deck panel

In order to improve the static and dynamic performance of long-span steel-concrete composite bridges, the design method of replacing concrete deck slab with ultra-high performance concrete waffle deck panel was put forward. Firstly, the formula to estimate the ultimate flexural capacity of a double reinforced T beam with a wide flange and low rib was proposed, which took into account the tensile strength of UHPC. Then, a simplifying method was presented to simulate a waffle deck panel with an equivalent anisotropic plate during the overall bridge modeling. Finally, a typical half-through tied arch bridge with designed UHPC waffle deck panel was taken as an example and its static and dynamic performance with UHPC waffle deck panel was compared to that with flat concrete slab. The results show that the average ratio of the calculation results of ultimate flexural capacity by the formulas to those of tests is 1.04 and the variation coefficient is 0.09, which proves that the formulas can be used to estimate the ultimate flexural capacity. The average ratio of vertical displacement from the equivalent anisotropic plate to UHPC waffle deck is 1.01, and the variation coefficient is 0.039. The equivalent anisotropic plate can well reflect the stiffness of a waffle deck panel. Compared with a flat concrete slab, the waffle deck panel reduces the deck mass by 40%, effectively reduces the suspender tension under dead load of completed bridge by 20%, the maximum stresses of key sections of the arches and steel beams decrease by 13% to 16% and the natural frequency of the structure is increased by 9% to 10%. The safely of bridge structure is improved. © 2020, Central South University Press. All right reserved.