Stress Characteristics of Voided Asphalt Concrete Panels

LING Bo; ZHAN Benxiang; LIU Anyao; LING Huikun

doi:10.3969/j.issn.1004-7328.2025.06.017

Abstract：Void defects pose a significant threat to the structural integrity of asphalt concrete-faced rockfill dams and downstream safety.A two-dimensional finite element model was established for a specific dam to analyze the stress types,magnitudes,and distribution characteristics in the face slab and cushion layer under different operating conditions,considering various positions and sizes of voided areas.The results show that voiding in the face slab leads to significant increases in tensile and shear stresses in both the slab and cushion layer at the voided area.The most pronounced tensile stress increases occur when voids are located near the dam crest or toe.Smaller voided areas are associated with higher tensile stresses,while larger voided areas lead to extensive tensile and shear stresses zones in both the cushion layer and face slab.Increased shear stress may exacerbate the voiding and separation effects between the face slab and cushion layer.The maximum tensile stress in the cushion layer occurs during rapid water level drawdown,while the face slab experiences maximum tensile stress at normal water storage levels.Both the cushion layer and face slab exhibit maximum shear stress during rapid water level rise.These findings provide valuable insights for preventing and mitigating voiding hazards in asphalt concrete face rockfill dams.