Stability Research And Parameter Analysis Of Spatial Irregular-shaped Cable-stayed Arch Bridge

Tied arch bridges and special-shaped tied arch bridges have become common types of Landscape Bridges and municipal bridges because of their light and beautiful characteristic.The stability,especially the lateral stability,is the key problem in the design and checking of tied arch bridges.In this paper,based on the existing theoretical derivation method of the lateral stability of the circular arc tied arch with single bearing surface and constant cross-section,the simplified solution method of the basic theory is first developed,and its rationality is tested by the simplified model and the parameter analysis is carried out.Furthermore,the problems of considering the lateral displacement of the beam,the axis of the parabolic arch,the axis of the hook function arch and the lateral inclination of the suspender are extended and deduced,in order to provide a theoretical reference for the preliminary design and auxiliary checking calculation of the stability of the tied arch bridge.Firstly,the basic theory is deduced and solved,and the expressions of roll stability critical load and non directional force coefficient are obtained,and the theoretical derivation method is verified by a real bridge case;On the basis,the first-order buckling mode of tied arch bridge and the membrane tension assumption of Suspender Force are analyzed.Then,the basic theory is extended.One is to theoretically deduce the roll stability of tied arch bridge considering the transverse displacement of beam.The key is to select the displacement function of beam and increase the relevant energy expression;The second is the roll stability of parabolic tied arch bridge,which is more widely used compared to the Circular arch.The key lies in the assumption of displacement function based on length coordinate and the concept of radius of curvature.Finally,the rationality of the two extended theoretical derivation methods is checked by the simplified model of the real bridge.The theoretical derivation of the roll stability of the special-shaped tied arch bridge is carried out.Taking the actual engineering case of Liyang energy storage power station as the starting point,two special-shaped factors of the bridge are extracted: the arch axis shape of the hook function and the non coplanar arch beam.Then,the method of considering only a single special-shaped factor each time is adopted to study the roll stability theory of these two problems respectively.The key extension of the former lies in the introduction of curvature radius and the selection of displacement function;The key extension of the latter lies in the selection of displacement function,the modification of elastic support deformation energy and the external force potential energy considering the influence of gravity.After completing the theoretical derivation,aiming at these two problems,a simplified model containing only the single special-shaped factor is established to verify the rationality of the theoretical derivation method.