Automatic Measurement Method Of Tunnel Cross Section And Software Development Based On Intelligent Total Station

The New Austrian Tunneling Method (NATM) and composite linings workings are increasingly used as the main construction techniques in native and abroad tunnel construction. In order to avoid the problems of over-break and excessive or insufficient excavation that may lead to unnecessary costs, the state of the surrounding rock during tunnel construction must be investigated. The engineering design can be reliably assessed and later construction guidance can be given. The same work and data collection must also be done in the stage of tunnel operation. For this purpose, the requirement for a very convenient and powerful measurement system have to be developed. The system should carry out fast and reliable tunnel section measurement and data processing in any conditions. The system can also be used to solve problem like automatic measurement of real profile shape and final approval assessment. Since the early 1990s, intelligent total stations came into the tunnel measurement fields. These advanced instruments have led to great influence on the traditional tunnel profile surveying. Users can develop the corresponding online measurement system of tunnel section based on given developing platform that the instrument producers offer, realizing the automatic measurement of tunnel profile.This paper chooses the TCRA1102 series total station produced by Leica company in Switzerland as hardware equipment for automatic measurement of tunnel cross section. The series have proved to be convenient, easy to control and accurate enough in the automatic measurement of tunnel cross section. Based on the open GeoBasic language provided by Leica corporation, the automatic measurement method of tunnel cross section is investigated in this paper. The software is also online developed based on the intelligence total station. In details the main issues studied in this thesis include the following.The GeoBasic instrument control language and instrument control instruction are introduced in the study. The simple and rigorous data adjustment models in the three-dimensional free-stationing measurement are especially discussed. The line median course and coordinate computation method in the free-stationing process are respectively investigated. The seeking method for tunnel cross section azimuth is proposed in this research. The data sorting mode and format conversion in this system are suggested in our experiments. The determination method for the real shape of tunnel cross section and the difference between the designed and formed profile are proposed in the thesis. The resulting data can be used to make formal reports with the corresponding figures and illustration. The online control code and analysis tools of measurement results have been integrated into the complete software. Also the above methods and functions have been realized in our system and the reliability and feasibility of this software have been applied in the tests.The algorithm and method proposed in this paper have been validated in our experiments. The testing results show that the proposed models for measurement of tunnel cross section are reliable. The online data processing software developed in the research can be used in automatic measurement of tunnel cross section in the field construction. The data processing part of the software can be used to compute the real area and analyze the difference between the designed and formed tunnel shapes. At the same time the monitoring report of tunnel cross section change can be established from the developed software. With the further development of the software the derived results from this investigation can be applied in the measurement of tunnel cross section.