基于Gudehus-Bauer理论的土-结构接触面亚塑性模型及应用OA

To describe the nonlinear,dilative,and strain-softening responses of soil-structure interfaces during shearing,a hypoplastic constitutive model for sand-structure interfaces that accounts for in-plane stresses is developed based on the eight-parameter Gudehus-Bauer hypoplastic model for sand.The pro‐posed model avoids the need to predefine yield surfaces and flow rules and overcomes the difficulty of ex‐tending conventional elastoplastic interface models to three-dimensional conditions.First,the three-dimensional stress tensor is reduced to a four-dimensional vector comprising the normal stress,two orthogonal shear stresses,and the in-plane stress,and a corresponding strain-rate vector is constructed.The modified stress and strain-rate components are substituted into the fundamental hypoplastic equation to derive the linear and nonlinear terms for the interface state.The model is then implemented in ABAQUS through a user material subroutine UMAT for finite-element analysis,and its predictive perfor‐mance is validated against test results for interfaces between dam fill materials and steel plates,Hostun sand of different densities and smooth panels,and Ticino sand and aluminum plates.Finally,the QZ4-D2 test pile of the Beijing Sub-Center Station Integrated Transportation Hub is simulated using an axisymmet‐ric finite-element model with a pile length of 68.3 m and a diameter of 1.2 m.For loads below 8 000 kN,the predicted settlements are in good agreement with the measurements,while at higher loads the proposed model provides more accurate predictions than the Mohr-Coulomb model does.At a load of 16 000 kN,the predicted shaft resistances at 12 depths have a mean absolute error of 9.13 kN and a mean absolute percent‐age error of 17.2%.The model also reasonably predicts the pile axial force,shaft resistance,and toe resis‐tance,demonstrating its numerical robustness and practical applicability.