ANALYSIS OF GROUND SETTLEMENTS INDUCED BY SUBWAY SHIELD EXCAVATION CONSIDERING SHELTERING
OVERLAPPED EFFECTS
ZHANG Zhiguo1，2，3，HUANG Maosong3，WANG Weidong4
(1. School of Environment and Architecture，University of Shanghai for Science and Technology，Shanghai 200093，China；2. State Key Laboratory for Geomechanics and Deep Underground Engineering，China University of Mining and Technology，Xuzhou，Jiangsu 221116，China；3. Department of Geotechnical Engineering，Tongji University，Shanghai 200092，China；4. East China Architecture Design and Research Institute Co.，Ltd.，Shanghai 200002，China)
Abstract：Ground settlements and underground structure deformation induced by subway tunneling are hot issues in the underground transportation construction safety control and risk assessments. Previous researches on ground settlements are basically concentrated on the soil free displacements，and the sheltering effects of adjacent existing underground structures are not considered. Based on the Shanghai tunneling case，the ground settlement rules induced by earth pressure balance(EPB) shield considering sheltering effects of tunnels in service are presented by using simplified analytical method，3D finite element(FE) numerical simulation method，and in-situ monitoring method. An in-depth analysis is conducted between ground settlements considering sheltering effects and those considering free soil displacements. In addition，the predicted deformation of subway tunnel induced by EPB shield during complex overlapped traversing process is also presented. It is observed that the simplified analytical method and 3D finite element method can perfectly simulate the ground movements induced by subway shield excavation considering sheltering overlapped effects. Furthermore，the sheltering effects have a major influence on ground settlements induced by EPB shield when the tunnels are excavated in the vicinity of existing buildings and structures. The differences compared with the results considering free soil displacements are obtained. Finally，the deformation controlling technical measures considering sheltering overlapped effects are proposed in combination of in-situ monitoring data. It may provide certain basis to build up correctly protective measures of geotechnical environments influenced by subway tunneling，especially the sites adjacent to existing buildings and structures.
LOGANATHAN N，POULOS H G. Analytical prediction for tunneling-induced ground movements in clays[J]. Journal of Geotechnical and Geoenvironmental Engineering，1998，124(9)：846-856.
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2013, Vol. 32 
