PURPOSES: This study proposes a cohesive shrinkage particle model that can be used to simulate a variety of dynamic behaviors and phase changes of construction materials, including road subsidence and debris flow, and phase change curing, via discrete element method (DEM).
METHODS : From the perspective of DEM modeling, the water-content-dependent characteristics of soil particles and related modeling techniques are reviewed from literature. The static friction, cohesion, and particle size change are considered as the major parameters that should be reflected in DEM modeling for a more realistic simulation. The relationships of water content with cohesive force and particle radius, as determined from experimental test results in the relevant study, are utilized to develop the cohesive shrinkage model. For each water content value, the snapshot in simulation is compared to that in the experimental study.
RESULTS: The numerical simulation shows very good agreement with the experimental test in terms of overall sample radius and thickness change due to drying. However, the local curling of soil sample in the DEM simulation does not perfectly match that in the experimental test. CONCLUSIONS : The cohesive shrinking particle model seems to be good enough for simulating the volumetric and phase changes of soil samples due to drying. However, it seems necessary to consider both bonding and cohesive contact models in DEM modeling because the only cohesive contact model exhibited limitations in the simulation of curling and crack development.

ABSTRACT
1. 연구배경 및 목적
2. 문헌고찰
    2.1. 함수비의 영향을 고려한 입자 모형
3. 토립자의 특성 변화 모형
    3.1. 완전 건조 - 표면 건조 상태
    3.2. 표면 건조 - Capillary 상태
    3.3. Capillary 상태 - Slurry 상태
4. 건조 수축 모사
    4.1. 접착성 수축 - 팽창 입자 모형
    4.2. 접착성 수축-팽창 모형을 활용한 모사 조건
    4.3. 접착성 수축-팽창 모형을 활용한 모사 결과
5. 결론 및 고찰
REFERENCES

• 윤태영(한국건설기술연구원) | Yun Taeyoung 교신저자