Application of a novel constitutive model to evaluate the shear deformation of discontinuity

Landslides are one of the most common geological disasters with the complicated spatiotemporal processes, which can be partially reproduced in slip shear failure along the discontinuity in laboratory tests. However, the assessment and evaluation of shear behavior along the discontinuity is time-consuming and high-cost. To solve this problem, a new constitutive model is proposed to predict the shear deformation behavior of the disconti-nuity. In this model, the discontinuity is assumed to be composed of intact units and failed units. In the shearing process, intact units and failed units jointly bear the external loads, and intact units are gradually transformed into failed units. A damage control variable is introduced to link the mechanical response of units with the macroscopic discontinuous deformation, thereby obtaining the final expression of the new model. The model parameters can be determined directly from several standard laboratory shear tests. Subsequently, the com-parison analysis among the predictive results of the new model, previous models and engineering projects is conducted. Finally, the sensitivity of model parameters is systematically discussed. A hardening index HI is proposed to characterize the shear deformation characteristics in the hardening stage, and its relationship with model parameters C and r is in a power form. The results are expected to provide theoretical guidance for landslide prediction and thus reduce the occurrence frequency of geohazards.