Simulation And Key Technologies For Construction Control Of Self-anchor Suspension Bridge With Large Segment Hoisting Construction

Self-anchored suspension bridge has become more and more popular, and has been widely used in urban medium and short span bridges because it has graceful modeling, economic advantages and adaptability to various. But of the complicated loading structure, the calculation of main girder initial construction state, main cable alignment and unstressed length of cables is also difficult, especially for the large segment hoisting construction steel girder self-anchored suspension bridge, the alignment control of the main girder is difficult. So, it is necessary to do some research for construction control technologies of the main girder alignment.Due to the calculation of self-anchored suspension bridge has great difficulty, combining calculation theories with FEM, reasonable construction control calculation methods was found, FEM model was established, and structural simulation calculation was made. Secondly, from the construction control view, the difficulties of large segment hoisting construction steel girder was made studies, including various controlling alignments, assembling error, temporary pier deflection, matching large segments, segment length accumulation error and segment local alignment error. Then, the error which 3 pre-camber setting methods brings to completed bridge alignment was calculated and adjusted, and influences which alignment adjustments bring to structure was analyzed. Nextly, the alignment and stress of structure which is affected by the deviation of the beam weight, was calculated detailedly in this paper. So, there were two ways to adjust the alignment:adjusting cable force or adjusting the erection alignment of steel girder. Then the influences caused by the two methods was analyzed. Due to various reasons, alignment control of the self-anchor suspension bridge was difficult, and the problems of alignment adjustment must emerge in the final structure. So, lastly the method of influence matrix was studied, and then a method of alignment adjustment was put forward based on the self-anchor suspension bridge, which can exactly and efficiently adjust the alignment of the main beam.Through analysis and calculation, "back-forward and zero-stress status analysis" construction control calculation methods was approached, the reasonable completed bridge states, stiffening girder initial construction state, main cable alignment and unstressed length of cables were found. For the difficulties of large segment hoisting construction steel girder, solution methods was put forward, and the alignment of steel girders in the process of assembling, erection and system transformation was exactly controlled. Taking various kinds of pre-camber setting methods into consideration, it is recommended that use the steel girder initial alignment (assembling alignment and erection alignment) which is calculated by "back-forward and zero-stress status analysis", this method can lead to completed bridge alignment with no error theoretically without adjusting cable force and changes in cable alignment and internal force, which can obviously reduce main girder alignment adjustment at last. It is known from the analysis and calculation that steel girder alignment of self-anchor suspension bridge is very sensitive to weight parameter of the girder. So alignment adjustment can make weight deviation offsetted by the internal force, then minimal alignment deviation is adjusted by the cable force. The method of influence matrix which is in this paper can exactly and efficiently adjust the alignment of the main beam. This method can be used not only in linear structures, to nonlinear structures, it can also be used repeated to obtain the purpose of adjusting the main beam alignment accurately.