Effect of External Prestressing on the Stability of a Flat Arch

For bridges with a slender bridge deck, ensuring sufficient stability under external loads is one of the technical problems that must be addressed. This paper studies the stability of a flat arch under asymmetric loads. Flat arch structures can form a directly walkable bridge deck. These structures can be realized without external prestressing only up to certain spans due to the necessity of capturing significant horizontal forces. The paper includes a static study that analyses the possible arrangements of the prestressing cables. The study evaluates the stabilizing effect of external prestressing and the possibility of creating a self-anchored system. Based on the results of the static study, a suitable variant was chosen for the design of a physical experiment. The experimental measurements compare the increase of stability for an arch discretely connected to a prestressing cable and an arch structure with a tie without mutual connection.