悬索桥施工过程精细化分析研究.pdfVIP

38 10 Vol138 No110 2 0 0 5 1 0 CHINA CIVIL ENGINEERING JOURNAL Oct1 20 05 罗喜恒 肖汝诚 项海帆 ( , 200092) : , , , , , , - , , , , , , : ; ; ; -; : U448125 : A : 1000- 131X (2005) 10-0076-05 DETAILED ANALYSIS OF CONSTRUCTION PROCESS OF SUSPENSION BRIDGES L uo X iheng X iao Rucheng X iang H af an (Tongji University, hanghai 200092, China) Abstract: With the increasing span lengths of suspension bridges, the ratio of main cable tension caused by dead loads to its bearing capacity is increasing while its safty factor is decreasing. Therefore, it is necessary to more accurately perform con- struction process analysis. The cable element based on exact analytical expressions for elastic catenary is perfected. A new el- ement, named as saddle-cable element, which can be employed to model all kinds of saddles and to convenientily simulate saddle jacking, is also proposed. This element contains two important conditions about the relationship between saddle and ca- ble, namely that the cable is always tangent to saddle and the total unstressed length of cable remains constant. According to the construction analysis characteristics of suspension bridges, a new method, which divides the unblanced force vector into prescribed parts and makes them act gradually in one loading step, is proposed to solve the nonlinear equations. The numeri- ca-l analytical method and FEM are combined to determine the ideal state of suspension bridges under dead loads. The proposed method, whose efficiency and accuracy are demonstrated by numerical examples, can be employed to exactly analyze the con- struction process, to optimize the construction scheme an