This book systematically introduces the new technology used in the construction of underwater large slurry shields under complex conditions. The basic principles, scope of application, construction technology and technical points of the key technologies such as the origin and arrival of the shield, crossing the shallow soil in the middle of the river, crossing the guard, and changing the knife and opening the knife are clarified.

This book proposes the tool change methods for the excessive tool wear in the construction rules of shield tunnel construction in China. From the perspective of shield tunneling, atmospheric pressure tool change, pressure opening and tool change, and other special techniques, the tool change technologies are proposed. It highlights a number of tool-changing techniques and research and development work, including pressure-changing tools, tool-changing tools in the tool-cylinder arm, and cutter-tooth cutter inter-change since the beginning of the construction of the Nanjing Yangtze River Tunnel.