Study On Space Attitude And Installation And Position Ingtechnology In Hoisting And Assembling Of Large Span Steel Truss X Arch Bridge

Taking the Nujiang four-lane large bridge as the engineering background,the precise installation and positioning technology for the long-span steel truss X-shaped arch bridge members in the process of lifting and assembly was studied.The Nujiang four-lane super large bridge is a 490 m top-support steel box basket arch bridge,and the arch circle is lifted and installed by a single bar of a horizontal cable crane.In the past,cable hoisting construction methods,whether segmented or single-member hoisting,did not establish a precise simulation mechanism for accurate alignment.It is difficult to achieve 100% design matching during construction.It is often passive during the construction process.Adjustment.In this paper,the geometrical conditions of the precise alignment of the lifting member and the forming ring member and the innovative jointing scheme that can adjust all the degrees of freedom of the aerial member are given theoretically.The proposed solution can automate the adjustment of the inclining angle of the bar and the small-scale traverse and horizontal plane rotation of the bar.The finite element software is used to establish the simulation model of the arch ring under the inclined buckle system according to the positive loading calculation method.Under consideration of the temperature effect,static calculation of the construction of the arch ring is performed,and each rod member is found out according to the design scheme construction.The splice joint node geometry.From the perspective of the cable crane,rigid body dynamics simulations were performed on the cable hoisting construction process,and the kinematics and dynamics processes during the hoisting and splicing process were simulated,verifying the feasibility of the proposed two mechanisms for spatial attitude adjustment of the bar.Sex.The cable lifting system is a multi-body mechanical system.The simulation is to enable the cable lifting system to accurately control the boom,and the boom can be paired with the existing ones.In fact,this is the solution to the kinematic and dynamic control of the system.The problem,of which we are mainly concerned with the geometric position information of the control point of the bar and the deviation from the geometric position information of the existing bar.Finally,the prospects for the automation of the rod assembly alignment were proposed.On-site construction can be based on the actual geometrical conditions of the two end faces coincide,and adjust the posture of the airborne lifting bar and the end face of the existing bar.Finally,only a small translation is required to complete the docking.The use of high-resolution cameras,optical alignment,and robotic arms in the translation stage enable automated docking.The use of manual crowbar pulls or other extensive construction methods was used to change the previous assembly of rods to avoid the build-up of construction errors due to the forced assembly and the difficulty in closing the dragons.