Research On Key Technology Of Super-large Bridge’s Deformation Monitoring During Operation Period

The rapid development of society and economy in our country accelerate the construction process of modern bridges,and the scale of bridge engineering also becomes larger.At the same time,higher requirements are needed in the construction and operation maintenance process of bridges.Thus,it is necessary to maintain survey system and monitor any deformation regularly during the super-large bridge’s operation period.However,considering the bridge structure characteristics and the actual measuring environment during the bridge’s deformation monitoring period,traditional measurement methods are usually unable to meet relevant requirements in field work and precision control.Therefore,this thesis will discuss the reasonable and feasible monitoring plan according to the actual situation and different bridge structures of the super-large bridges during operation period,as well as its application.So the main studying contents of this thesis are shown as follows:Firstly,in view of the actual requirements of geodetic datum network connection survey during the super-large bridge’s operation period,a new measurement method based on geo-robot simultaneously subtending observation for obtaining indirect height difference in trigonometric leveling between the cable-stayed bridges and the second-order leveling on the bridge deck is introduced in detail,In addition,its feasibility and accuracy are also analyzed.Secondly,the deformation monitoring position of the super-large bridges is often far away from the datum points on the river banks,For this reason,some base points should be laid on the bridge deck near the monitoring position.However,the base points on the bridge deck is not stable because of bridge body temperature’s influence,so it is necessary to study the methods that connection survey of all basic work points and datum points on the banks and deformation monitoring of bridge structures by using the base points could be carried out at the same time,and a special measuring device would be designed to avoid unstable base points’ influence on the deformation monitoring process of bridges in sea.Thirdly,in order to realize the horizontal displacement monitoring of the bridge pier’s top in sea,and considering the actual measurement conditions such as the bridge pier’s top is covered by the bridge deck and the narrow surrounding space of monitoring position,the horizontal displacement monitoring of the bridge pier’s top in sea is carried out through the method of free station measurement by using the base points on the bridge deck,and its feasibility and precision are also discussed.Fourthly,in order to realize inclination deformation monitoring of the bridges in sea,and considering the actual measurement conditions of the monitoring position’s narrow surrounding space during the operation period of the bridges in sea,the inclination deformation monitoring of the bridges in sea is carried out through the method of polar coordinates surveying based on free station no-prism measurement with no-prism by using the base points,and its feasibility and precision are also discussed.What’s more,the thesis mainly studies the methods of field data processing and analysis.Finally,the technical plan of the above measurement work is designed,and it is applied to the actual deformation monitoring of a sea-crossing bridge in Hangzhou Bay during operation period.The actual monitoring results prove that the achievements of this thesis are feasible and correct.