Papers by Author: Cai Liang Huang

Abstract: Because the multi-box girder bridge has many advantages, such as large torsion rigidity, large load-bearing capacity, stability, fine appearance, good applicability and convenient construction, it is widely used in China. But for the defection existing in design and construction, many box girders have serious diseases. Aiming at the diseases of a viaduct bridge, the causes of diseases are analyzed and the enforcement method is proposed in this paper. The study shows that, though the box girders have large torsion rigidity, the diaphragms are designed necessarily to enhance the transversal connection between the box girders, to make them bear the loads together, to reduce their stresses and deformation, and to reduce the stresses of deck too.

Abstract: Long-span flexible bridges are always challenged by fierce wind load, and the wind with extreme-attack-angle may be a potential danger to threaten the bridge security. The three-component coefficients at extreme attack angles of the section model of one flat streamlined box-girder and central slotted box-girder are investigated through the wind tunnel test, and the detailed explanation are made. The results show that lift and pitch coefficients change approximately linearly between stall angles, and the coefficients display significant nonlinearity and a certain pulsation phenomenon when the attack angle exceeds stall angles, and the stall angles should not be less than ±10° for the sake of the safety of bridges.