APPLICATION OF GEO-SPATIAL INFORMATION TECHNOLOGY IN THE ENGINEERING MANAGE OF ROLLER COMPACTION CONSTRUCTION
J i a n Zh a n g 1 , X i a o - L i n g C H E N 1 , 2 1 St a t e K e y L a b o r a t o r y o f I n f o r m a t i o n E n g i n e e r i n g i n S u r v e y i n g , M a p p i n g a n d R e m o t e S e n s i n g ( L I E S M A R S ) , Wu h a n U n i v e r s i t y, Wu h a n , P. R . C h i n a , 4 3 0 0 7 9 ) Zhangjian_36@126.com Phone: 86-27-13986084638
Geo-Spatial Information Science (Geomatics) is a comprehensive and integrated information science and technology, which is used to acquire, measure, analysis, store, manage, display, diffuse and apply the data related to earth and spatial distribution. Global Position System (GPS), Geographic Information System (GIS), Remote Sensing (RS) and other spatial information technologies are it’s main contents (Deren Li 2005). Computer and communication technologies are its major technical support. Geomatics is a new developed science represented by “3S” technology including communication and computer technology. The US Department of Labor identified geotechnology as one of the three most important emerging and evolving fields, along with nanotechnology and biotechnology. (V Gewin 2004). With the rapid development of “3S” technology, its application in other fields have became more and more extensively. For example, it widely used in engineering management field, especially in the construction management of large construction projects which include a large of spatial information. Generally, the construction management of these projects is very difficult, because it needs a large number of investments, a long construction time complexity of building steps. The traditional engineering management methods for project management can not be informed the progress of the project with fast and visual methods. Besides, it can not efficient control the quality, progress and costs of the project. At present, the applications of engineering management based on the computer information technology are very popular at home and abroad, but it’s rarely use the spatial information technology. Spatial information technology will be introduced to engineering management filed to construct of EGIS (Engineering Geographic Information System). It not only have the past engineering information management system functions, but also have a powerful and unique ability with spatial information technology, such as graphics performance, spatial analysis, 3D visualization , etc. In addition, we could use GPS technology to achieve real-time monitoring and quality controlling of construction process. Based on the analysis and study of the RCC(roller compaction construction) process of an engineering construction management project of dam filling and rolling which the author participated, a RCC EGIS (roller compaction construction Engineering Geographic Information System) based on spatial information technology had been developed. Below, the main functions, technology Route and the key technology of this system will be introduced. The hardware of the RCC EGIS is made up of the GPS systems, the wireless communications systems and some computers, etc. Because of the system's users (owners, the construction side and supervisor) scatter in the different site. And taking into account the requirements of all parties, the network framework of RCC-EGIS is the combination of B/S and C/S based on WebGIS technology. The C/S structures have the Construction Engineering Information Management Center (CEIMC) and engineering Information database. The B/S structure has the construction site mobile monitoring platform (CSMMP). The RCC EGIS can real-time monitor the construction site by the GPS which put on the roller. The position data which collected through the GPS had been sent to the engineering information database by the GPRS wireless network. Through the analysis of the data by the CEIMC, we
can automatic monitor the height of the filling construction site, the position and status of the roller trucks, which could be displayed through the 3D visualization method. Similarly, the times of paver and the roller compacted can be calculated and displayed. All the monitoring results can be published to the CSMMP, which aid the manager of the construction site to supervise with interactive and real-time mode. Because RCC EGIS have real-time, continuous, automated, high-precision and visual characteristics, several key technologies needed advanced study such as real-time monitoring of roller compaction parameters, data compression, data accuracy and spatial interpolation methods. 1 Real-time monitoring of roller compaction parameters According to the observational data of GPS which placed in the roller truck, we can real-time monitor and guide the construction. The RCC EGIS choose GPRS wireless network to send the data of the GPS Differential Reference Station to the moving GPS and send the data of the moving GPS equipments to the CEIMC,which compute the position of every moving GPS equipments each second. 2 Data compression The data redundancy will happen and the time of reading data will be prolonged, when the track of the roller truck displayed directly. So the algorithm of vector data compression based on wavelet had been used in the RCC EGIS, which could accelerate the reading and display speed of the track data. 3 Data accuracy This system uses GPS RTK technology, the distance from the moving GPS equipments to the GPS Differential Reference Station not more than 3 km. Its horizontal position accuracy can meet the requirements, such as the track, speed and direction of the roller trucks, the rolling frequency. After testing and applications, it shows that the height measurement precision can reach (1 ~ 3) cm accuracy if the following aspects can be accomplished. Firstly, the distance between the moving GPS equipments and the GPS Differential Reference Station could be control in a certain range. Secondly, high-performance and anti-jamming dual-frequency GPS receiver could be choosing. At last, the data collection methods in the construction site must be studied. 4 Spatial interpolation Because the construction process need be real-time monitored and quality controlled, the data collected from the roller trucks could generate the elevation surface through spatial interpolation to aid the manager to decide the process of constructing. The Kriging spatial interpolation method had been chosen. It fully utilizes the spatial correlation and reflects the spatial anisotropy of data under the interpolation operation. In this paper, the spatial information technology will be introduced to engineering management filed to construct of EGIS. The RCC EGIS designed based on spatial information technology, which achieved real-time monitoring and quality controlling the construction process. It has a powerful and unique ability with spatial information technology, such as graphics performance, spatial analysis, 3D visualization, etc.