The major task of tunneling is excavation and support .Recently, there are some improvements aimed to enhance the “accuracy” & “safety” of D&B method, to promote the efficiency and mobilization of mechanical-excavation , and have achieved some noticeable results .Using pour-in-place concrete and well-mixed shotcrete to maintain the sufficient support in time. Introducing computer technology to integrate the “construction management information” will promote the tunneling construction technology to a higher automation field.
The construction process of a NATM tunnel consists of geological data logging and rock mass rating, monitoring of the changes of rock strain and stress, as well as blasting and excavation. In the past, when conducting the data recording, engineers need to look up many reference books and then to calculate the results by hand. The results could be display on the trend charts to judge the next action. It is difficult and not efficient to execute all of the tasks in the poor jobsite environment.In order to improve the situation, The purpose of this paper is to build up a decision-supported system, named “the Integrated Rock Tunnel Logging and Decision-aid System.” The functions of this system include geotechnical logging, rock mass rating, cross-section prediction, moritoring data recording and its graphical display, and construction data collection and analysis. The system combines the concepts of multimedia MIS and DSS. This system has a convenient user interface and an integrated data structure that encompassed all the information about the tunnel construction process.
The most evident effects caused by external force application, worsening construction material quality or other factors are cracks and water inflow appearing on concrete lining. Techniques such as visual measurement, ground penetration radar, drilling and sampling are still being used for tunnel inspection nowadays. Because these traditional techniques were originally designed to be used for inspection of constructions in open space, efficiency and accuracy using these techniques are not sufficient when they are used to inspect tunnel which is a longitudinal enclosed space. In view of this deficiency and with their long historical background in tunnel constructions, the Europeans have developed an automatic inspection system for this purpose. The system makes use of combined techniques of visual image, thermal image and space scanning techniques. Scanner with 360 degree rotation capability, can very quickly and accurately gather visual image, temperature, and clearance information for the entire length of tunnel. Investigation of the collected data will help to lead us to the reasons of the unusual appearance in the tunnel.
Deformation measurements and profile surveys of tunnels are the key elements to ensure the safety of tunnel construction and to improve the construction quality. Traditional methods not only waste efforts and time but can not reflect the complete conditions of tunnels. Recently, there are great automation improvements developed in these areas. This paper will describe the equipment, the functions and features, the operation procedures, and the data analyses of these automatic techniques. The safety evaluation procedures of the optical measurement technique which are different from traditional methods will be introduced.
The application of shield construction is increasing in urban area, due to its low environmental impact, high efficiency and safety. The shied construction technique which was heavy manpower oriented before has to be improved by automation because of the higher living standards and changing labor conditions. The implementation of automation should be step by step and consider the domestic conditions. This paper will give an overview of current situations of the automation in shield construction. It is hoped that the automated shield construction will be implemented with best efficiency domestically.
Static pile loading test using standard cyclic loading method is a time consuming work which may last for several days. The newly developed equipment presented in this paper consists three parts: driving system, measuring system and micro- processor system. The new test needs one person only to operate the computer controlled system and key in requiring data, load and time duration, for each cycle, and the test will run automatically. Using this method, the reading error and time lag for loading and unloading process happened during conventional test can simply be avoided.
The highway construction in Taiwan is gradually extended to suburban and mountainous area instead of the over developed city area. For the past few years, there are more and more failure cases of tunneling in coal mine area, since the coal mines are located in the northwestern foothills. The tunneling problems, i. e., settlement, deformation, and failure, due to the adjacent coal mine are significant. Careful considering the influence of the coal mine is necessary for a successful tunnel design and construction in this area.In this study, boundary element method together with displacement discontinuity element are used to simulate the problem of tunneling through coal seams. The analysis result of stress and strain distribution around the tunnel can be used to estimate the influence of the mine to the tunnel. A real case in northern Taiwan was analyzed and a mining restricting area is also proposed for the safety of tunneling.