Research on in-tunnel disassembly schemes of shields in confined space metro section tunnels
Shield method is a widely adopted construction method for metro section tunnels.In situations where a receiving well is not available,in-tunnel disassembly of the shield upon arrival would become necessary.However,disassembling the shield in a confined space presents significant technical challenges and construction risks.This study addresses the issue of continuous dismantling of multiple shield machines in the tunnel construction project of the airport to the Qianhai section of the Guangzhou-Dongguan-Shenzhen intercity railway.Through an in-depth analysis of the key difficulties in the construction process,such as the complexity of shield equipment removal,limited workspace within the tunnel,difficulties in retracting double-mode shields,constraints on lining templates,and numerous safety risks,a construction scheme and process tailored to the engineering situation were developed.Additionally,key construction technologies for the continuous dismantling of multiple shield machines were proposed.Through a suitability analysis of the dismantling plan,successfully enhanced its economic viability and dismantling efficiency.The research results serve as a reference for shield in-tunnel disassembly projects in confined space metro sections.