Long-Distance Tunneling of Shields and Replaceme...
During the long-distance shield tunneling，it is very important to effectively solve the tunneling problems such as instability of excavation face，excessive surface subsidence，and dislocation of segment assembly.Among them，the problem of frequent shutdown of shield caused by obstacles or excessive wear of cutters has become an important problem in shield construction in China.Opening maintenance is the main means to eliminate shield faults and remove obstacles.Due to the position of forced shutdown of shield is often in the deep buried depth，complex hydrogeological conditions or the bottom of the river and other adverse environment，under the action of soil pressure and water pressure of the stratum，there is a great safety risk in opening the cabin.Therefore，how to carry out safe cabin opening has become a key technical problem of shield tunnel industry in China.This chapter introduces the long-distance tunneling technology through the adaptability of shield cutter，and summarizes the common faults and corresponding detection technology of shield.At the same time，combined with the mud film air-closure method，the shield cutter replacement technology with pressure is introduced.