Study On Construction Techniques Of Composite Shields In Guangzhou Metro

Along with the metro,underground drainage, electricity and other tunnel construction is developing rapidly,shield tunneling technology with the unique intelligence, security, quickness and other features and advantages,has been more extensive promotion and application.This thesis, based on experience of tunnel construction with shield driven method of metros in Guangzhou selects several focal points from a series of key links of construction with shield driven method and probed into them, that is, start of composite shield driven, primary tunneling, mode selection under normal tunneling and conversion of work situation, control of shield driven posture and treatment of rectifying deviation, reaching tunneling and end consolidating treatment, etc.; makes calculated analysis in details for some key parameters, such as thrust force of composite shield and torque moment, etc. and transportation system within tunnel constructed by shield driven method through concrete works examples; deeply studies existed problems and their countermeasures of composite shield under complicated geological conditions; analyzes in details contributing factors of construction accidents in some aspects during composite shield driving and puts forward concrete prevention and resolving measures, and combining with actual works examples, puts forward concrete measures for protecting buildings and dealing with pile foundations intruded into tunnel section during construction of city metros.From above analysis, the thesis gets conclusions as following:①It is the base and key for propitiousness complete shield driven,choosing dynamic schemes, choosing cutter head and cutters,designing diversified assistant functions direct towards cases of stratum.②It is the key for propitiousness driving,designing thrust and torque,because the geology condition is complicated in Guangzhou.③The work ability of screw transportation equipment and seal brush of shield end has prominent affect for driven effect.④The multi drivening modes are corresponding cases of stratum.It should grasp conversion condition of different driven modes,that can adopt compatible driven mode in first time,with reference theory analyzing, information of earth and information of ground subsiding.⑤Tunneling is a complicated systematic project, from selection to the final of the...