Research On The Static Characteristics Of Deck Type Inclined Column Bridge

Studying on new type of bridge and improving the existed bridge type are always the pursuit of practitioners of bridge industry and that direction also have huge prospects for development and technological innovation space. In this paper, a new type of bridge structure which is called inclined column bridge is proposed to solve the problem of vertical stiffness of long-span bridges. The finite element models based on MIDAS/Civil are established to study the static characteristics of deck type inclined column bridge:(1)This paper firstly introduces the basic structure and mechanical principle of the inclined column bridge. Then the paper introduces the construction technology of the upper deck inclined column bridge.(2)The finite element models are established to study, to compare and to analyze the deformation, internal force, stress and structural stability of the upper deck inclined column bridge and the deck arch bridge under different load condition. Research shows that the vertical stiffness of the upper bearing inclined column bridge after the adjustment of cables is higher than that of the deck type arch bridge under each load condition when the displacement of girder and bending moment of inclined column are considered as the objective control function to adjust the cable, which proves that the mechanics balance principle of inclined column is correct.(3) Prestressed force can significantly decrease the bending moment and shear force of inclined column under dead load, but it will also increase the axial force of inclined column. It indicates that although the prestressed force of cables can bring better vertical stiffness, it also brings no small burden of internal forces to the structure. However, the maximum stress (including cable stress) after checking of bearing inclined column type bridge and arch bridge is less than the the allowable stress of specification under each loading condition. So, structural strength of two type of bridge is enough.(4)The linear elastic buckling analysis of two type of bridge structure are conducted. The analysis shows that when the dead load and the dead load of the two phase are considered as the invariable load, the most unfavorable loading condition of the live load is considered as the variable load, the static stability of the upper deck inclined column bridge is better than that of the upper deck arch bridge.(5)In this paper, the influence of structural parameters variation on the static characteristics of the upper support inclined column bridge is studied. Study shows that measures of increasing the horizontal angle of inclined column, closely spaced stay-cables, properly increasing the prestressed force of cables can improve the vertical stiffness of bearing inclined column bridge to some extent, and can decrease the bending moment of inclined column. Closely spaced stay-cables and increasing prestressed force will increase the axial force of the inclined column. Therefore, how to obtain well vertical stiffness and to prevent that the internal forces of inclined column are too large to lose bearing capacity at the same time can be depended on the above several measures to determine the design scheme.The results of this paper can provide reference for the understanding of the static characteristics of the upper supported inclined column bridge, and can also provide reference for the design of structural members with similar principles.