Research purposes: Control of the safety risks of shield machine launching and gong out of the tnnel is a critical process in construction of shield tunnel. For construction of the river - crossing slurry shield tunnel of the Line 2 of Wuhan metro,this paper presents the safety control system for the shield machine launching and going out of the tunnel and analyzes the application effect of the risk control so as to provide the reference to the similar works.
Research conclusions:The rapid,effective and reliable balance between the environment and shield construction parameters can be established by conducting the risk control of the whole process,including the beforehead control,matter control and subsequent control in the construction phrase. In the launching process of the shield machine,the monitoring points should be installed along the vertical axial cord position of tunnel according to the relative standards.During the tunneling of the shield machine,the tracing monitoring should be conducted and the dynamic analysis,the advanced alarm and the feedback should be conducted with the security alarm system for metro construction in order to provide the decision - making basis for adjusting the construction parameters of the launching tunneling section.