The sediment of the Kangding Bank of Luding Dadu River Bridge of Sichuan-Tibet Expressway mostly consists of very thick moraine soli. In order to study the shear creep characteristic of moraine soil and the long-term deformation of bridge gravity anchor, the in-situ shear creep test was carried out using automatic data acquisition system. Based on the test result, the shear creep characteristic, creep model and long-term deformation of gravity anchor of moraine soil were analyzed. The results showed that the duration of transient creep was less than 0.1 h. In addition, the transient creep was characterized by delayed deformation after loading, and the creep rate fluctuant decrease in the decelerating creep stage. In addition, the creep rate was characterized by stepped growth and multi-stage change in steady creep stage, and jump phenomenon could be found in the shear deformation-time curve, which indicated the deformation adjustment effect of soil skeleton particle. The experiment of shear creep test of moraine soil showed a small creep deformation and convergence creep characterized by creep rate gradual decreasing when the shear stress was less than the long-term strength. The creep deformation rapidly increased when the shear stress was close to or larger than the long-term strength. For the convergence creep characteristic of moraine soil, the non-linear modified Burgers model was used to describe the shear creep characteristic of moraine soil. According to the fitting model of the test result corresponding to the stress level of gravity anchor of Luding Dadu River Bridge, the long-term deformation of gravity anchor of Luding Dadu River Bridge is predicted to be millimeter magnitude, which is preliminarily validated by time series InSAR and deep displacement monitoring. The proposed method of analyzing long-term deformation and stability of structures based on shear creep test result, can be considered as a reference for design.
