A numerically controlled tunnel boring machine for experiments with controllable excavation section shape

Abstract

The invention relates to a numerically controlled tunnel boring machine for testing with controllable excavation cross-section shape, which includes a support frame, a motion mechanism that is arranged on the support frame and can move freely in the X-Y-Z direction, is installed on the motion mechanism and The excavation mechanism that moves with it, the movement mechanism includes an X-axis assembly, a Y-axis assembly and a Z-axis assembly that drive its load along the X, Y, and Z directions respectively, wherein the X-axis assembly is arranged on the support frame, The Y-axis assembly is installed on the X-axis assembly, and the Z-axis assembly is placed on the Y-axis assembly. The tunneling mechanism includes a ZD conversion unit, a drive assembly, a spindle and a tool. The ZD conversion unit is set on the Z-axis assembly and can move along the Z direction. , the drive assembly is installed on the ZD conversion unit, one end of the main shaft is connected to the output end of the drive assembly, and the tool is fixed on the other end. Compared with the prior art, the present invention can carry out linkage in three directions, so that tunnels of any shape can be excavated, and the difficulty of tunnel model tests and the like are reduced.

Description

technical field [0001] The invention relates to a tunnel excavation system in a model test, in particular to a numerically controlled tunnel boring machine for testing with controllable excavation section shape. Background technique [0002] Model tests play an important role in revealing the distribution of stress and displacement in the surrounding rock of underground tunnels, as well as the failure form and mechanism of the surrounding rock. When carrying out model tests, how to simulate tunnel excavation is a major difficulty. At present, there are mainly two methods to achieve this: one is to replace the soil to be excavated with other easily removable materials or molds, and just remove the substitutes when simulating excavation. Such as patent CN103616287A, CN104634932A published tunnel excavation model test device respectively will be excavated with rosin with low melting point and easily soluble polystyrene foam material pouring form, the excavation of the tunnel i...

AI Technical Summary

Problems solved by technology

This method is more commonly used but has obvious disadvantages: (1) The properties of the filling material or the mold and the surrounding rock are quite different, and there will be differential bearings during the initial loading, and the initial stress state before the tunnel excavation cannot be truly restored; ( 2) The pouring shape of the filling material or the processing accuracy of the mold are not easy to control, which may easily cause excavation deviation; (3) It is difficult to realize segmental excavation, and most of them can only roughly simulate the instantaneous excavation of the whole section, so the surrounding rock cannot be considered Spatiotemporal Effects of Forced Deformation

Obviously, this method is more realistic, but it is difficult to implement in the test. The main problems are as follows: (1) The excavation accuracy is not high, and the tunnel profile after excavation is uneven, with randomness. If parallel tests are carried out, It is difficult to ensure the same excavation conditions; (2) It is usually used for the excavation of tunnels with simple shapes, but it is difficult to complete the excavation of tunnels with complex contour shapes; (3) Time-consuming and laborious

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