Study on Railway Subgrade Settlement induced by an Ultra-Large-Diameter Shield Tunnel Crossing under Railway Subgrade

This paper presents a study on the influence of construction an ultralarge-diameter shield tunnel undercrossing existing high-speed railway using empirical method, numerical analysis and geotechnical centrifuge model experiment based Wuhan Lianghu Highway Tunnel project. The comparison results obtained from three methods shows first, that simulation match well with method for worst-case scenario most likely scenario, which are consistent unfavorable geological conditions modeled in test possible simulation. Second, both show asymmetry settlement subgrade was induced by tunnel, while curve is gradually weakening tunneling. Third, maximum could vary between 20 mm (in scenario) 65 worst scenario). Both allowed value differential along (5 mm/10 m) would be exceeded when excavation passes first track at 10 m. It indicates some mitigation measures should taken controlling especially machine about underneath pass subgrade. suggested underpass during skylight period operation.