Abstract:

Ground settlement is hard to control during EPB shield tunneling in saturated fine sand. If the supporting measures for buildings, which are underpassed by shield, are not adequate, the buildings are easy to settlement, crack or collapses. Taking the settlement control for Tianruncheng commercial building and Tianruncheng bus station, which are located on No.3 line of Nanjing metro and underpassed by EPB shield in saturated fine sand of Yangtze River floodplain, as study object, experimental driving and parameter election before shield tunneling, tunneling parameters analysis and adjustment during shield driving and buildings monitoring and evaluation after shield driving are presented in this paper. In light of the analysis of measures and parameters used in shield driving under buildings, some suggestions are proposed for shield driving in fine sand and settlement control, including immediately filling clearance between surrounding rock and segments during shield driving in saturated fine sand; thrust, advance speed, rotation speed of cutterhead and muck conditioning during tunneling is vital for stratum stability; efficiently settlement control and environmental protection can be achieved, via efficient settlement control measures and comprehensive and careful analysis and dynamic parameters adjustment during shield driving. 

Key words: shield, floodplain of Yangtze River, saturated fine sand, settlement control