岩土力学2026，Vol.47Issue(8)：2665-2675,11.DOI:10.16285/j.rsm.2025.0881
考虑结构性演化的非饱和黄土水-力耦合弹塑性本构模型
Hydro-mechanical coupling elastoplastic constitutive model of unsaturated loess considering structural evolution
摘要
Abstract
Loess exhibits distinctive properties,including notable macroporosity,water sensitivity,and structural characteristics,with its mechanical behavior being significantly affected by saturation levels.This study focuses on the constitutive modeling of the coupled hydro-mechanical elastoplastic behavior in structured loess,employing Bishop's effective stress and saturation as the primary driving variables within the model framework,while considering the corresponding soil skeleton strain and suction as conjugate variables.Accounting for the variation in structural properties with saturation,we introduce saturation-dependent yield stress structural parameters and frictional strength structural parameters,and formulate an evolution equation for these structural parameters in relation to plastic strain and saturation.Utilizing the yield equation for remolded saturated loess as a foundation,we construct the LC(loading-collapse)yield equation for unsaturated structured loess within the effective stress-saturation space,based on the correlation between saturation and yield stress.A volumetric strain-dependent soil-water characteristic curve is adopted to delineate the hydraulic behavior of loess.By integrating volumetric strain with its mechanical response,we establish a coupled hydro-mechanical elastoplastic constitutive model for unsaturated loess.The model encompasses 14 parameters,which can be calibrated through standard unsaturated triaxial tests and isotropic consolidation tests.The model's validity is confirmed by predicting the outcomes of compression and shear tests on loess under conditions of constant suction and constant moisture content,and comparing these predictions with established experimental data.The findings demonstrate that the model accurately captures the yield strength of loess across varying saturation levels,forecasts the strain softening behavior of unsaturated loess under low confining pressures,and adequately describes the coupled hydro-mechanical behavior of structured loess,thereby offering essential theoretical underpinnings for deformation and stability analyses in loess engineering.关键词
非饱和黄土/结构性参数/水-力耦合/软化行为/结构性演化Key words
unsaturated loess/structural parameter/hydro-mechanical coupling/softening characteristics/structural evolution分类
建筑与水利引用本文复制引用
李林,张淼,李尧,段智博..考虑结构性演化的非饱和黄土水-力耦合弹塑性本构模型[J].岩土力学,2026,47(8):2665-2675,11.基金项目
国家自然科学基金(No.52578385,No.52508429) （No.52578385,No.52508429）
中国博士后基金特别资助项目(No.2023T160560) （No.2023T160560）
中央高校基本科研业务费资助项目(No.300102215101) （No.300102215101）
省部共建特色金属材料与组合结构全寿命安全国家重点实验室开放课题(No.MMCS2023OF03).This work was supported by the National Natural Science Foundation of China(52578385,52508429),the Special Support Project of the China Postdoctoral Science Foundation(2023T160560),the Fundamental Research Funds for the Central Universities(300102215101)and the Open Foundation of State Key Laboratory of Featured Metal Materials and Life-cycle Safety for Composite Structures(MMCS2023OF03). （No.MMCS2023OF03）
