Study On The Composition And Ring Selection Technology Of Universal Segments For Shield-driven Tunnels

As a sophisticated tunnel lining type, the universal segments can do a good job in the control of the axis of shield-driven tunnel and the quality of segment ring. The deviation control of segments erection to fit the Designed Tunnel Axis (DTA) is an important standard for the construction quality of shield-driven tunnels. This thesis mainly takes research on the composition and ring dynamic selection technology of universal segments. The details of the research are as follows:Since the designed composition of segment ring is to fit the DTA, we need to describe the line, circle and connecting curve, which are commonly used in DTA, with mathematical model according to their designed parameters. Geometric equations of the axis are deduced in order to realize the coordinate conversion between the ring's mileage and its three-dimensional coordinates. It proves that this method works well, and it has higher precision than the insert-line method.Analysis of segment composition is presented. The flow process about how to choose the optimal erecting position is programmed, following the principle that the minimum deviation is the optimal choice. The designed composition of segments is realized, and we can get the information of rings on the DTA, including the location, erecting position, coordinates, deviation and so on.It is necessary to consider the behavior of the TBM, in order to make the ring dynamic selection close to the lining construction. So the artificial intelligence theory is introduced. The fuzzy algorithm control method is used to adjust the direction of shield machine, and to simulate its short-term excavation. Considering that the TBM should go along the DTA, the difference of jack push-length can be calculated, which takes part in the ring selection process.On the basis of analyzing the factors which influence the ring selection and their relationships, the objective function for selecting ring's turning angle is deduced. It takes jack push-length, shield tail gap, segment turning angle, and deviation of curve fitting as consideration. The rings' prediction and the control of the TBM are...