Study On The Linear Control System Of Continuous Girder Bridge In Short-line Prefabrication Phase

Due to the many advantages of short-line assembly prefabricated method,the method is being used in the construction of more and more concrete bridges.However,during the use of short-line matching method of the construction,because of the lack of effective controllation in the geometric line of the bridge,the bridge line can not achieve the required accuracy,therefore,the use of short-line assembly prefabricated method was limited.In order to speed up the pace of bridge construction in our country and also to further promote the construction method of short-line assembly prefabricated method,it is very necessary to seek an effective control method.The main contents of this paper are the following aspects:(1)The construction technology of prefabricated concrete bridge with short-term assembly is introduced.The methods and precautions of segmental prefabrication are introduced from the aspects of steel skeleton construction,concrete segmental construction and the lifting and storage of segmental beams.(2)The section segmentation principle of short-line bridge,linear construction principle of curved bridge and linear control flow in prefabricated stage are introduced.The main factors of the alignment of prefabrication stage from the aspects of template system control,positioning control of matching beam and field measurement control are analyzed.(3)The method to calculate the coordinates of the control point of the matching segment is proposed.By calculating the key parameters of the beam length,the plane and the vertical declination of the adjacent segments,the matching positioning coordinates of the new pouring segment can be obtained.Aiming at the errors produced in the process of prefabrication,the adjustment and correction methods of error correction are proposed.(4)On the basis of the theoretical research,Visual Basic for Application programming language is used as the research tool of Windows program,the data processing is done by using Microsoft Excel,and the linear control system of prefabricated bridge prefabricated stage is prepared.(5)Combined with the engineering example,the linear control method and control system discussed in the paper are applied to the actual project of linear control and the linear control system is tested by comparing the actual line and theoretical line of the bridge to verify the effectiveness of the system.