Dredged soft soil reclamation area using ocean clays experiences sedimentation and
self-weight consolidation process. Simultaneously, the dry process progresses on the surface of dredged soil area so that a desiccated surface crust layer is created. For the evaluation of trafficability on this dredged soil area, a reasonable calculation of bearing capacity is necessary. Nevertheless, researches on the bearing capacity of the soft clay layer including upper crust layer are deficient.
In this paper, the Discrete Element Method (DEM) is applied for reasonably estimating the bearing capacity of heterogeneous multi-layered soil deposits which have a crust layer between the very soft clay and over filling sand layers. The main advantages of the proposed method are that it easily simulates the tensile reinforcement effects and considers a variety of possible failure modes. By applying the proposed method, the distribution of shear stress and plastic states in the assumed failure plane can be estimated. For the validation of the proposed method, the DEM analysis results were compared with the results of the suggested bearing capacity theories. Various example problems of the cases of single layer, two layers and reinforced two layered soil were analyzed and the results were compared with those of plate loading tests. Parameteric studies on important parameters which affect the ultimate bearing capacity were also carried out.
Consequently, the proposed method resulted in valid solutions for all the cases and thus the bearing capacity of reinforced multi-layered soil deposits could be appropriately evaluated by the proposed DEM analysis program.
준설 매립 지반은 침강 및 자중 압밀 과정을 겪게 되고 표면에서는 건조 과정이 진행되어 건조 고결층이 형성된다. 이러한 지반에서의 장비 주행성 평가를 위해 합리적인 지지력 산정이 필요하다. 본 논문에서는 합리적인 지지력 산정을 위하여 개별요소법(DEM)이 적용되었다. 제안된 방법의 효용성 평가를 위해 단일층, 이층 지반, 보강된 이층 지반의 경우에서의 다양한 예제들이 해석되었고 그 결과를 현장평판재하시험 결과와 비교하였다. 또한 극한지지력 산정에 중요한 영향을 미치는 요소들에 대한 민감도 분석도 실시하였다. 결론적으로 모든 경우에 있어서 제안된 방법은 유효한 해석결과를 보였고 보강된 다층 지반의 지지력도 제안된 DEM 해석 프로그램에 의해 합리적으로 산정 가능하다고 판단된다.
