Research On The Soil Disturbance Between10m Diameter Shield And6m Diameter Shield

Nowadays, more and more tunnels are used large-diameter shield method toexcavation. In order to improve the efficiency of construction, the excavation diameterof the shield is also increasing. Shield tunnel excavation process, inevitably willstratum to disturb a certain disturbance, and make the displacement and deformation tothe surrounding strata and surface. When the deformation of ground surface is largeenough, it will pose a threat to the safety of the underground pipeline. There has been alot of research about the soil disturbance, deformation laws and sphere of influence forthe small diameter shield. But specifically for the large-diameter is limited.With the construction of the section of Dongfengbeiqiao–Jiangtailu on the line14,by the field trials, theoretical analysis, it summed up the settlement percentage in thevarious settlement stages when the large diameter shield is excavating in this regionand analyzed the influence range on the transverse surface settlement.FLAC3D software is used to build a numerical model of large-diameter shieldconstruction. It simulated the settlement trough between the large-diameter excavationand small-diameter excavation, and compared them. And put forward the forecastingand assessment methods, thereby reducing the impact and avoided the risk-averse, sothat the smooth construction.There is something gap between the prediction and actual measure with the PECKformula of large diameter shield. Therefore, this article proposed a correction factor αand β to the settlement trough and the width of settlement trough, to predict thesettlement of large diameter shield of the Beijing accurately.