Study On Bridge Construction Drawings Based On ObjectARX

The bridge design is one of the most onerous task in the design and reconnaissance of highways. And the inconsistencies of the design, calculation and drawing data can be resulted from the error of calculation and graphics because of its heavy load and numerous data, and not only the intensity of the work is large and the efficiency is low in manual graphics, but also the quality can not be guaranteed. Therefore, the CAD technology of Bridge Aided Design is needed raringly. Currently, certain results have been made in the development and application of domestic bridge CAD systems, and the bridge design software is becoming perfect gradually and used widely in the engineering design, while they mainly focus on the calculation of the bridge structure, but seldom on the graphics.In order to solve this problem, aiming at the characteristic of standardization of the bridge design and construction, and referring to the existing software---WXQ, the paper studies the graphics of parameter design in bridge and develops the CAD graphics system of bridge using Visual C++ and ObjectARX.First, the paper conceives a basic frame of Pre-stressed Concrete Bridge CAD system, and compares a variety method of program development, then selects the stable and efficient AutoCAD platform and uses the powerful secondary development functions of ObjectARX, finally combines the Windows visualization resources, the object-oriented C++ language and the graphics disposal function of AutoCAD organically and this can improve the speed and the quality of program development.Second, the paper studies the automatic drawing of the box-girder section, the layout of the pre-stressed steel beam and the infrastructure of the bridge, and then proposes a mode of program design and calculation. Especially in the graphing of pre-stressed steel, referring to the horizontal and vertical pre-stressed load and the bending, the paper proposes a concept of "prestressing cable model" which describes the prestressing cable model and provides the parameters of controlling the "prestressing cable model" and the layout of prestressing cable based on the analysis of the characteristic of pre-stressed steel beam, and achieve the goal of parametric drawing of prestressing cable model.Again, the paper defines the group of prestressing cable model, interface, infrastructure and pile using the object-oriented C++ language; moreover, the paper produces the drawings of bridge-section, the horizontal and vertical prestressing cable, the infrastructure of the bridge and the layout of the steel in the pile with the help of the combination of MFC dialog technology and the powerful object operating function of ObjectARX, which achieve the goal of direct graphics in the AutoCAD.Finally, the author proves the utility and the feasibility through the application of the working examples. And the developed software function can reduce the workload greatly for the graphics in AutoCAD of bridge design. Besides, the paper can direct the further work clearly from the defect in the practical application.