The Study Of Homemade Shield Cutting Tools For The Shield Construction On A Layer Of Gravel And Scree

In recent ten years, the method of shield tunneling has been developed quickly on the construction of urban subway in China. It also had been applied to pipeline crossing Yangzi River and channel, displaying advantages of this crossing method.Shield tunnel construction in the ground of sand and gravel is a major problem for tunnel construction at present. The most important thing is to retain stabilities of advancing face and lengthen using life of cutting tools. This paper takes construction plan design, selection of tunneling machine type, stabilities of cutting face, wearing and replacing of cutting wheel and tools as the problems be solved mainly to study in the course of tunnel construction in the sand and gravel through referring to many documentation and combining project practice.Regarding stabilities of cutting face, there are two approaches to obtain, one is to select and design suitable cutting wheel so as to enlarge the working scope of tunneling machine, another is to adopt proper construction method of cutting face stabilization to prevent face collapse and quicken construction speed. Therefore, through drawing on the construction techniques and case at home and abroad, speed up the mixing ratio and modified testing in the course of study of slurry application, a set of special advancing method in the layer of sand and gravel has been formed for the slurry balance tunnel machine.The cutting tools are the wearing and consumable parts because of advance wearing and bearing stress from advancing among the spare parts. A great number of cutting tools being used is imported at present. In order to reduce dependence on the imported cutting tools, this paper make discussion with clear aim for cutting wheel and tools. During the design and development of cutting wheel and tools, we cooperated with Jiangzuan Engineering limited Company to make research and improvement on cutters so that the quality and performance of products becomes more reliable and perfect through the analysis of stress on the wheel and cutters and record the damage patterns.This subject study has been practiced and applied on the field. It has obvious effects whatever the technical feasibility, practicability and economic benefits.