The Development Of The Shield Tunnelling Test System

Shield method is a way of tunnelling in soft soil or rock, a cutting head cuts the rock or soil continuously, and various support materials are installed in the tunnel after cut. Shield method has many advantages, such as high speed, high precision, small vibration, low noise, has little impact on the surrounding buildings, etc. It is important to research and develop high-efficiency, economical shield technology, which is useful for the development of urban underground engineering. This thesis introduced a new developed shield tunnelling test system. This test system included test rig, soil box, cutting head conveyer system, hydraulic system, and measurement system. The test system was used for excavating experiments in different soil and rock, and the results of the experiment will be used to support for better tunnelling organization.Forces on knife when cutting soil or rock were analysed and calculated based on soil and rock mechanics. Furthermore, the force and torque of each knife was calculated by three theoretical methods. The parameters of the cutting were obtained by the theoretical calculation, and the method also founded the optimization of the arrangement and shape of the cutting tools.Based on parameters obtained by theoretical study, the overall mechanical system was designed. Parts such as cutter head, driven system, thrust system, conveyer system and soil box all designed through calculation. The hydraulic system was also designed through detailed calculation. All standard parts involved in the test system included hydraulic component, gear box and sensors were selected by calculation.After the mechanical system were manufactured and installed, a PC base data collecting system was developed. The data collecting and processing system was developed by LabVIEW software, which has functions of calibration of the system, self-test system, data acquisition and processing and so on. This system significantly simplified the experimental process, avoiding the trouble and errors of manual acquisition of large amounts of data. The real-time acquisition and processing of data is more perfect to the model system.All system was debugged after developed and put into use in the experiments. A manual of the operation of the system was also make out, and hence finished the whole development.Latter experiments on the test system show that the development of the whole system is successful, all specifications meet the requirements. The test system has finished many experiments of shield tunnelling in different depth, different geological conditions, the results have played an important role in Beijing subway construction.