The transverse settlement induced by the construction of a parallel shield tunnel alongside the building has raised considerable attention

whereas few studies focus on the longitudinal settlement. Therefore

the spatial deformation of ground developed from this tunneling form is investigated. In this study

some field measurements from the shield tunnel section of Tianjin Metro Line 6 parallel to four similar masonry buildings in vicinity are analyzed first

and the deformation pattern is established. Then

a hardening soil model calibrated against field measurement

considering small strain stiffness

is implemented in a three-dimension finite element simulation to evaluate the longitudinal deflection of the buildings

the ground deformation

and the soil stress distribution. Additionally

the effect of building aspect ratio is discussed. The simulation results show that tunneling-induced sagging deformation develops along the longitudinal direction of the building

and the settlement at the middle of a longitudinal wall is twice of that at the corners. Therefore

the study of tunneling parallel to buildings cannot be simplified to a plane strain problem. The building construction and tunneling activity result in the soil above the tunnel crown experiencing a complicated stress history

which can be divided into six stages. In longitudinal direction

compared with the part below the building foundation corners

the soil in the middle initially behaves larger compressive deformation due to building construction

followed by greater unloading deformation caused by tunnel excavation. In addition

the longitudinal sagging is significantly reduced for the buildings with aspect ratio less than 2.