Study On Construction Control System Of Long-span Suspension Bridge

Based on the engineering practice, the paper carries a through analysis on the construction control of the long-span suspension bridge. It makes some research achievements in the following aspect:1. The calculation theory and precision make great improvements on the present established calculation approach in that in the calculation of cable construction control, the paper takes into account the fact that the second deadload is jointly borne by the cable and the stiffening-girder and uses the knowable saddle set apex instead of cable theoretical apex, a condition formerly hardly to identify. The paper also presents an easier and feasible modification on the cable length in terms of known coordinates of saddle set apex. And it establishes analytic method of catwalk construction control on the basis of catenary theory. This analytic method considers the imbalanced level force caused by the separate location of catwalk in middle-span and margin-span.2. In this paper ,an accuracy bound model of cabel in anchorage span is founded, its formula is also derived. It solves the application of vibration method to the tension tests of long-span suspension bridges. This research model can also be used in the suspender tension tests. Furthermore the paper demonstrates in details the influence of temperature variations on the tension control of cable in anchorage span.3. The paper presents a new mechanical model of elastic sustaining girder and corresponding calculation method. It offers more exact calculation model for geometric state of stiffened box girder during construction. By exploring the essentials of pre-displace of cable saddle and its push, the paper gives suggestion of the time and frequency of saddle push.4. The paper develops MCTI(the especial instrument of temperature test with 64 channels).The application results obtained from the real bridge prove that MCTI is reliable, precise, convenient and matches the national leading level.5. By continual temperature tests and strain tests on the steel stiffened box girder through the construction, the paper, after extensively analyzing the temperature data obtained from tests, puts forward the temperature grads curve and c alculation model for the horizontal and vertical of the steels tiffened box girder under the sunlight, a finding which is a very important supplement to the perfection of present bridge design criteria. Moreover the mathematical model and simplified calculation method presented in the paper offers a simple and convenient approach to the effect of temperature analysis of steel stiffened box girders.