Research On Method And Practice Of The GPS Surveying In The Large-scale Bridge Building Control Survey Project

In traditional large-scale bridge building survey control network establishment process, As a result of the engineering factor limit, uses conventional much the control survey method side, also is through measurement equipment and so on the altazimuth, distance gauge, entire station meter, level establishes takes a bearing the net, measures the net or the corner network. These conventional control survey method work loads very big, work time long, condition influence and so on the climate, environment is been remarkable, moreover the error accumulates remarkably. Emerges unceasingly along with the large-scale bridge building, like the Hangzhou bay cross sea bridge such cross sea length achieved especially 30 kilometers bridges also appeared. Regarding these large-scale bridge buildings, both banks intervisibility is extremely difficult, must use the tradition measuring technique direct build bridge project control network and carry on the bridge construction survey is extremely not easy. Therefore, studies one kind to suit in the large-scale bridge building construction high accuracy control surveys and constructs the survey method to be extremely essential. But the GPS technology production and the development has provided the possibility to this kind of question solution.This article research content mainly is take the Hangzhou bay bridge severed head control network survey project and the following GPS continuous running reference station service system construction as an example, in detail elaborated how establishes the large-scale bridge using the GPS localization technology the horizontal control network and the elevation control network, and has carried on the multianalysis to the data processing flow, deliberated how has established the project GPS continuous running reference station service system, For is accurate, effectively carries on the bridge construction survey to provide thetechnology to guarantee, And will carry on the construction survey to the later large-scale bridge building using the GPS localization technology establishment survey control network to have the high reference function. The research content and the achievement include specifically:1) Large-scale bridge building GPS horizontal control network build. Has made the analysis and the research to the horizontal control network build request and the precision estimate, formulated on the spot from this and the basis situation has spread a net the plan and the observation plan. The net shape basis begins reckoning a distributed situation and the bridge construction characteristic, used take the bridge spool thread as nearby the center of gravity, the length unified spreads a net the way; The control point symbolized the establishment used the deep pile to force to the center to observe the way which the pillar and the ordinary monument unified; The GPS observation has used technical method and the work measure and so on high accuracy GPS geodetic survey pattern;2) GPS horizontal control network data processing. Mainly has carried on the detailed analysis and the discussion to baseline Xie Suan and net adjustment these two parts, and the partial GPS baseline and the precision range finder result which calculated the solution have carried on the comparison. The GPS data processing through the association measured the IGS tracking facility, has introduced the high accuracy ITRF97 international geocentric coordinate reference frame, has used the IGS precise star experience. Baseline processing use international famous Bernese and Gamit software; The GPS net adjustment used PowerNET, PowerADJ and so on the many kinds of softwares has carried on each kind of adjustment and the precision evaluates and so on;3) Routine measurement data and GPS data union adjustment. In the GPShorizontal control survey, realized has carried on the criterion in the high accuracy project control network using the routine measurement data to the GPS data to compare the control, and the routine measurement data and the GPS data union adjustment computation. Through joins the variance examination in the adjustment software, reasonably decides on the different observed value the power, has overcome the GPS data and the routine measurement data compatibility, in the processing method does not have the innovation mutually, And has obtained the anticipated effect;4) Large-scale bridge building elevation control network build and data processing. Because both banks not impossible to surmount directly, Through three kind of different fitting plans result analysis, in even ground (for example terrain change not complex), if the known bench mark distribution is even, hopes using the GPS elevation fitting to obtain the good achievement;5) Has established the project GPS continuous running reference station service system, and to established this system to carry on feasible and the necessary analysis, has formulated the concrete technical plan, solved essential technical question and the technical difficulty. For was accurate, effectively carries on the bridge construction survey to provide the technical guarantee.