English：

In order to solve the technical problem of safe tunneling in ultra-small spacing parallel shieldconstruction, based on the Fenghong section tunnel project of Suzhou Metro Line 7, aiming at theproblem of ultra-small spacing interaction, a new protection system for small spacing parallel shieldconstruction is innovatively adopted, which is “MJS interlocking isolation wall + radial deep hole groutingin tunnel + synchronous support of tunnel first + mud effect grouting outside shield later”. A synchronousbalance roof support system with servo precise control, automatic walking, large angle climbing and smallcurve turning function was independently developed. The external load, horizontal displacement ofinterlayer soil, segment convergence and pipeline settlement were monitored and analyzed, and thevariation law and influence range of parallel crossing additional load and horizontal displacement ofinterlayer soil under different conditions were revealed. Finally, the safety control of ultra-small spacingparallel shield construction is realized.