Research on Spatial Data Structure of General-plan of Construction Managing Information System

General-plan of construction managing information system focuses on the management of construction information and analyzes on construction processes. Deep issues on spatial data structure of the system are illustrated in this paper. By analyzing charaeteristics of the construction project,we propose a kind of map-block-entity data model that can deal with complex spatial operations and is propitious to the update and maintenance of system data. This paper divides the whole map information into basic map information and extended map information. When the map is processed, the basic map information is shown only, don't take part in the construction of topology, but other information on the map is changed at any moment according to the actual demand.By reducing quantity of spatial data of system, the operation speed including query and search is improved obviously using this method. At the same time, the article tries to create topology relations of entities composed of map-blocks and brings forward the method of automatic creation. It is well known that to create the general topology relation on the objects with a large number of parts is very slow and complex.It is not necessary to make such a complex topology structure because the consumers care for the exterior information of the projects instead of the interior constitution of them. The system sets up a series of polygons with nodes by the relation of the map-blocks, and then uses the common method of creating polygon topology to build the system topology relation. By doing that, we can speed creating the system topology and decrease the number of data that are used during system operation. Therefore,it is obvious that the information query and spatial analysis are more efficient. The spatial data structure of the system has been used in the Three Gorges general-plan of construction managing information system. With the need of managing the construction information scientifically, the special information will be adopted widely. As follows, the suited spatial data will be required strongly.